Boomplantweek en die Internasionale Jaar van Woude - Dendro.co.za
Boomplantweek en die Internasionale Jaar van Woude - Dendro.co.za
Boomplantweek en die Internasionale Jaar van Woude - Dendro.co.za
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EXTRA
Aloe dichitoma » Foto: Jan Lerm<br />
Acacia erioloba (kameeldoring), Thabazimbi » Foto: Gideon Steyn<br />
<strong>Boomplantweek</strong> <strong>en</strong> <strong>die</strong> <strong>Internasionale</strong><br />
<strong>Jaar</strong> <strong>van</strong> <strong>Woude</strong> 2011<br />
Die meeste natuurlike inheemse bosse <strong>en</strong> woude<br />
in Suid-Afrika kom hoofsaaklik in <strong>die</strong> ooste <strong>van</strong><br />
<strong>die</strong> land, al langs <strong>die</strong> kuslyn voor. Alhoewel hier<strong>die</strong><br />
inheemse woude <strong>die</strong> kleinste biome is, word <strong>die</strong><br />
grootste biodiversiteit hier aangetref. Verder noord<br />
<strong>en</strong> in <strong>die</strong> binneland kan klein lappies woude aan<br />
<strong>die</strong> suid-oostelike hange <strong>van</strong> <strong>die</strong> Soutpansberg <strong>en</strong><br />
Drak<strong>en</strong>sberg in Limpopo <strong>en</strong> Mpumalanga, asook in<br />
<strong>die</strong> binneland <strong>van</strong> <strong>die</strong> Oos-Kaap <strong>en</strong> Kwa-Zulu Natal,<br />
aangetref word. Die meeste <strong>van</strong> hier<strong>die</strong> woude is<br />
nie groter as 100km2 nie. Die uitsondering is <strong>die</strong><br />
<strong>die</strong> Knysa- <strong>en</strong> Tsitsikama-woude, wat relatief groot<br />
oppervlaktes beslaan. Die totale oppervlakte <strong>van</strong><br />
inheemse woude in Suid-Afrika beslaan ‘n skamele<br />
0.5miljo<strong>en</strong> hektaar <strong>van</strong> <strong>die</strong> totale oppervlakte<br />
<strong>van</strong> Suid-Afrika. Daarte<strong>en</strong>oor bedek uitheemse<br />
aangeplante plantasies, wat hoofsaaklik uit<br />
Eucalyptus <strong>en</strong> Acacia spp. afkomstig uit Australlië<br />
<strong>en</strong> Pinus radiata uit Noord-Amerika bestaan, 1.7<br />
miljo<strong>en</strong> hektaar of 1.2% <strong>van</strong> <strong>die</strong> totale landmassa in<br />
Suid-Afrika.<br />
E<strong>en</strong>s op ‘n tyd het natuurlike woude <strong>die</strong> grootste<br />
gedeelte <strong>van</strong> <strong>die</strong> aarde se oppervlakte bedek.<br />
Vandag word hier<strong>die</strong> woude te<strong>en</strong> ‘n tempo <strong>van</strong> 35<br />
km2 per dag vernietig. Die ketting reaksie wat dit<br />
veroorsaak het ‘n vernietig<strong>en</strong>de uitwerking op <strong>die</strong><br />
biodiversiteit, verhoogde grond erosie <strong>en</strong> verlies<br />
aan water. Voor <strong>die</strong> aankoms <strong>van</strong> Europeërs in<br />
Suid-Afrika gedur<strong>en</strong>de <strong>die</strong> 17de eeu, het groot<br />
troppe olifante <strong>en</strong> buffels in <strong>die</strong> Suid-Kaapse<br />
woude voorgekom. Die <strong>die</strong>re moes swig voor <strong>die</strong><br />
geweervuur <strong>van</strong> <strong>die</strong> kolonialiste, <strong>en</strong> in 1883 is <strong>die</strong><br />
laaste buffel in <strong>die</strong> Knysna-woud geskiet. In 1920<br />
was daar ongeveer 12 olifante in <strong>die</strong> woud oor, <strong>en</strong><br />
volg<strong>en</strong>s ‘n opname in 1994, was daar slegs e<strong>en</strong><br />
olifant oor. Vandag is dit onseker of daar nog <strong>en</strong>ige<br />
olifante in <strong>die</strong> woud voorkom. Die Dukukdukuwoud<br />
in <strong>die</strong> noorde <strong>van</strong> Kwa-Zulu Natal, wat e<strong>en</strong>s<br />
e<strong>en</strong> <strong>van</strong> <strong>die</strong> grootste inheemse woude in Suid-Afrika<br />
was, beslaan <strong>van</strong>dag ‘n oppervlakte <strong>van</strong> net 3500<br />
hektaar. Gedur<strong>en</strong>de <strong>die</strong> tydperk tuss<strong>en</strong> 1800 <strong>en</strong><br />
2000 het <strong>die</strong> inheemse woud oppervlakte in Suid-<br />
Afrika met ongeveer 40% verminder. Die grootste<br />
volume <strong>van</strong> woud produkte word deur plattelandse<br />
Naas Grové<br />
voorwoord<br />
preface<br />
geme<strong>en</strong>skappe b<strong>en</strong>ut, waar<strong>van</strong> brandhout<br />
ongeveer 51% verte<strong>en</strong>woordig. Die gebruik <strong>van</strong><br />
plantprodukte in tradisionele medisinale praktyke,<br />
afkomstig <strong>van</strong> spesies soos Cassiporea malosana,<br />
Erythropleum lasianthum, Oc<strong>co</strong>tea bulatta, Catha<br />
edulis <strong>en</strong> Warburgia salutaris, het tot gevolg dat <strong>die</strong><br />
meeste <strong>van</strong> <strong>die</strong> hier<strong>die</strong> spesies op <strong>die</strong> rand <strong>van</strong><br />
uitwissing is.<br />
Dit is onder andere te<strong>en</strong> dié agtergrond dat <strong>die</strong><br />
Ver<strong>en</strong>igde Nasies besluit het om 2011 as <strong>die</strong><br />
<strong>Internasionale</strong> <strong>Jaar</strong> <strong>van</strong> <strong>Woude</strong>, met <strong>die</strong> hooftema<br />
M<strong>en</strong>se <strong>en</strong> <strong>Woude</strong> te verklaar. Die doel hiermee is<br />
om <strong>die</strong> m<strong>en</strong>sdom bewus te maak dat volhoubare<br />
woud bestuur, bewaring <strong>en</strong> volhoubare<br />
ontwikkeling <strong>van</strong> alle tipes woude tot voordeel<br />
<strong>van</strong> <strong>die</strong> huidige <strong>en</strong> toekomstige geslagte is. Ons<br />
het immers nie <strong>die</strong> aarde by ons ouers geërf nie,<br />
maar le<strong>en</strong> dit by ons kinders.<br />
Ek het myself al baie <strong>die</strong> vraag gevra of e<strong>en</strong> m<strong>en</strong>s, of<br />
e<strong>en</strong> geme<strong>en</strong>skap of ‘n paar vrywillige organisasies<br />
‘n verskil kan maak in <strong>die</strong> lewe <strong>van</strong> kinders, <strong>die</strong><br />
planeet <strong>en</strong> ons omgewing? Dit is m<strong>en</strong>se soos<br />
Wangari Maathai, <strong>die</strong> K<strong>en</strong>iaaanse kampvegter vir<br />
<strong>die</strong> bewaring <strong>van</strong> K<strong>en</strong>ia se inheemse woude, wat ‘n<br />
m<strong>en</strong>s weer hoop gee. Sedert 1977 was sy betrokke<br />
by <strong>die</strong> ‘Gre<strong>en</strong> Belt Movem<strong>en</strong>t’ in K<strong>en</strong>ia <strong>en</strong> dit het in<br />
2004 aan haar <strong>die</strong> Nobel prys vir Vrede besorg.<br />
Haar leuse inspireer <strong>van</strong>dag nog duis<strong>en</strong>de gewone<br />
m<strong>en</strong>se: ‘…wh<strong>en</strong> we plant trees, we plant the seeds of<br />
peace and seeds of hope’.<br />
Behalwe vir <strong>die</strong> verskill<strong>en</strong>de boomplant aksies<br />
waarby <strong>die</strong> D<strong>en</strong>drologiese Ver<strong>en</strong>iging <strong>van</strong>jaar<br />
betrokke was, is daar ook in samewerking met<br />
<strong>die</strong> SABC se Radio Sonder Gr<strong>en</strong>se (RSG) ‘n projek<br />
geloods om inheemse groot bome op te meet. (kyk<br />
berigte elders). Dit is ‘n projek waarby <strong>die</strong> hele<br />
familie betrokke kon raak, <strong>die</strong> natuurwet<strong>en</strong>skappe<br />
onderwyser, sy leerlinge asook <strong>die</strong> boer op<br />
<strong>die</strong> plaas. Wanneer ons dus hier<strong>die</strong> jaar ‘n<br />
boom plant, do<strong>en</strong> ons dit met ‘n gesindheid <strong>van</strong><br />
verantwoordelikheid <strong>en</strong> <strong>die</strong> wete dat ons saam ‘n<br />
verskil kan maak.
Cussonia paniculata var. sinuata » Foto: Marnhe du Plooy<br />
I never saw a dis<strong>co</strong>nt<strong>en</strong>ted tree. They grip the ground as though they<br />
liked it, and though fast rooted they travel about as far as we do. They go<br />
wandering forth in all directions with every wind, going and <strong>co</strong>ming like<br />
ourselves, traveling with us around the sun two million miles a day, and<br />
through space heav<strong>en</strong> knows how fast and far!<br />
26<br />
32<br />
34<br />
65<br />
Dialogue / Dialoog<br />
07 Die Gansbaai-boom<br />
Tree Stories / Boomstories<br />
09 Die Thabazimbi-bosveld se groot kremetart<br />
12 Komm<strong>en</strong>taar oor <strong>die</strong> groot kremetart <strong>van</strong> Gannahoek<br />
15 The twins that became triplets<br />
16 Tree Survey in Sekhukhuneland<br />
Review / Review<br />
STAY IN TOUCH / BLY IN KONTAK<br />
Web: www.d<strong>en</strong>dro.<strong>co</strong>.<strong>za</strong><br />
Email: d<strong>en</strong>drosoc@esnet.<strong>co</strong>.<strong>za</strong><br />
Fax: 086 670 7715<br />
Postal: Postnet 2054, Private Bag 82234, Rust<strong>en</strong>burg, 0300<br />
Besoek ons ook op Facebook vir meer interaksie.<br />
Find us on Facebook for more intercation.<br />
COVER PHOTO / VOORBLAD FOTO<br />
Carp<strong>en</strong>ter Bee on Crotolaria cap<strong>en</strong>sis (Cape Rattle-pod)<br />
Foto g<strong>en</strong>eem deur: Lloyd Edwards<br />
inhoud<br />
<strong>co</strong>nt<strong>en</strong>ts<br />
23 Some <strong>co</strong>mm<strong>en</strong>ts on Tšate from a member of the Botanical Society<br />
26 Die Maroelabos <strong>van</strong> Tshipise-”duin”<br />
28 Palmbome: Koninklike plante<br />
32 Mynbou in Limpopo provinsie Die D<strong>en</strong>drologiese Ver<strong>en</strong>iging se rol<br />
34 Classification and nom<strong>en</strong>clature of the g<strong>en</strong>us Acacia<br />
44 Underground trees of the Pondoland C<strong>en</strong>tre<br />
47 Virtual Tree Herbarium (ViTH)<br />
49 The Tsate Heritage Site in Sekhukhuneland<br />
52 Vertroetel jy uitheemse indringerplante in jou tuin?<br />
55 Is bome swak kosmakers?<br />
58 New tree species dis<strong>co</strong>vered in KwaZulu-Natal<br />
59 Die invloed <strong>van</strong> swart turf op boomdiversiteit<br />
Bye<strong>en</strong>komste / Ev<strong>en</strong>ts<br />
65 Grootvadersbos excursion<br />
66 Grootboommeet-kompetisie<br />
68 Boomplantfunksie saam met Solidariteit Help<strong>en</strong>de Hand<br />
68 D<strong>en</strong>drological Society Pays for Radar Scan of Tree Giant<br />
68 New Africa Tree Re<strong>co</strong>rd<br />
5<br />
DENDRON » No/Nr: 43 » November 2011
DENDRON » No/Nr: 43 » November 2011<br />
6<br />
editorial<br />
boomgroete<br />
EDITOR / REDAKSIE:<br />
Naas Grové<br />
LANGUAGE EDITING /<br />
TAAL REDIGERING:<br />
Naas Grové<br />
DESIGN / ONTWERP:<br />
Marnhe du Plooy,<br />
Room for Design<br />
COVER PHOTO:<br />
Lloyd Edwards<br />
PUBLISHER/UITGEWER:<br />
D<strong>en</strong>drological Society of<br />
South Africa<br />
D<strong>en</strong>drologiese Ver<strong>en</strong>iging<br />
<strong>van</strong> Suid-Afrika<br />
PRINTING:<br />
4 Images<br />
ADVERTISING /<br />
ADVERTENSIE:<br />
d<strong>en</strong>drosoc@esnet.<strong>co</strong>.<strong>za</strong><br />
MEMBERSHIP /<br />
LIDMAATSKAP:<br />
d<strong>en</strong>drosoc@esnet.<strong>co</strong>.<strong>za</strong><br />
ADDRESS / ADRES:<br />
Honorary secretary/<br />
Ere-sekretaris<br />
Postnet 2054,<br />
Private Bag/ Privaatsak<br />
82234<br />
Rust<strong>en</strong>burg, 0300<br />
PHONE / FOON:<br />
+(27) 82 575 4244<br />
FAX / FAKS:<br />
+(27) 86 670 7715<br />
EMAIL / E-POS:<br />
d<strong>en</strong>drosoc@esnet.<strong>co</strong>.<strong>za</strong><br />
WEB:<br />
www.d<strong>en</strong>dro.<strong>co</strong>.<strong>za</strong><br />
ISSN : 1991-1539<br />
What do members get for their annual<br />
subscribtion fee?<br />
Very oft<strong>en</strong> we are <strong>co</strong>nfronted by members who chall<strong>en</strong>ge the C<strong>en</strong>tral Committee<br />
with questions such as ‘what b<strong>en</strong>efits are there in joining the Society and what do we<br />
get for our subscription?’<br />
Although this is not an attempt to justify the work of the members of the C<strong>en</strong>tral<br />
Committee, it is maybe worth the effort to <strong>co</strong>ntemplate on what has be<strong>en</strong> happ<strong>en</strong>ing<br />
‘behind the sc<strong>en</strong>es the past year’.<br />
editorial<br />
boomgroete<br />
• Annual newsletters are designed and published at a <strong>co</strong>st of approximately R 6 500 per newsletter<br />
• Publishing of the glossy D<strong>en</strong>dron magazine at the <strong>en</strong>d of the year at a <strong>co</strong>st of betwe<strong>en</strong> R 24 000 and R 38 000<br />
• The time that goes into the <strong>co</strong>nt<strong>en</strong>t managem<strong>en</strong>t, image sourcing, layout and proofreading, roughly amounts<br />
to 120 hours – that excludes the time and efforts of the <strong>co</strong>ntributors.<br />
The total annual rev<strong>en</strong>ue of the society through subscription fees amounts to ± R 65 000. The curr<strong>en</strong>t debtors<br />
are at < R 15 000. From the C<strong>en</strong>tral Committee’s managem<strong>en</strong>t position we secured substantial donations and/or<br />
sponsorships for the following projects, which in all fairness should in a perfect world be financed by means of<br />
normal rev<strong>en</strong>ue streams:<br />
• Upgrading and maint<strong>en</strong>ance of the website (<strong>co</strong>ding, SEO optimisation, maint<strong>en</strong>ance, annual registration)<br />
• Because most of the members of the C<strong>en</strong>tral Committee are still e<strong>co</strong>nomically active, Machelle Kukard does<br />
all the administration at a nominal fee of R 500 / month, donated by one of the members of the C<strong>en</strong>tral<br />
Committee. Machelle can be directly <strong>co</strong>ntacted for membership and subscription <strong>en</strong>quiries via e-mail at:<br />
info@electro<strong>die</strong>sel.<strong>co</strong>.<strong>za</strong><br />
• Printing of promotional material which is being issued to schools and other interested parties at special<br />
occasions such as arbor week to create awar<strong>en</strong>ess and grow our society<br />
• Upgrading of our ac<strong>co</strong>unting and membership administration systems<br />
• Inputs to the National Register of Big Trees in South Africa where we travel vast distances to measure<br />
nominated trees, all at own <strong>co</strong>st<br />
• Developm<strong>en</strong>t of tree id<strong>en</strong>tification training <strong>co</strong>urses (both theoretical and practical). Curr<strong>en</strong>tly we offer four<br />
<strong>co</strong>urses per year with a total rev<strong>en</strong>ue of R 20 000<br />
• In <strong>co</strong>njunction with SABC Radio Sonder Gr<strong>en</strong>se we launched, as part of Arbor Week 2011 and the International<br />
Year of Forests, various radio talk shows betwe<strong>en</strong> 1 and 8 September as well as a ‘big tree measurem<strong>en</strong>t’<br />
<strong>co</strong>mpetition. All the prizes for the latter have be<strong>en</strong> sponsored by individuals.<br />
• Together with SANBI we printed A0 Tree of the Year posters which is distributed to our sponsors, schools,<br />
nurseries, etc.<br />
• The Society donated R 10 000 from sponsorships received to the Dictionary of South African Trees by Van<br />
Wyk, Van d<strong>en</strong> Berg, Coates-Palgrave & Jordaan<br />
• None of the above would have be<strong>en</strong> possible had we only relied on membership fees.<br />
Over and above what I have already m<strong>en</strong>tioned, members of the C<strong>en</strong>tral Committee pay visits to various branches<br />
throughout South Africa at their own <strong>co</strong>st. We also travel long distances to deliver tree talks at various occasions<br />
such as agricultural shows, <strong>co</strong>nfer<strong>en</strong>ces, schools, etc.<br />
With regards to activities at branch level we leave it pretty much to the local structures to keep our members<br />
satisfied, stimulated and involved. It is the local managem<strong>en</strong>t <strong>co</strong>mmittee’s prerogative to interpret the society’s<br />
mission in a way they deem fit, as long as it doesn’t damage or <strong>co</strong>mpromise the society’s image in any way.<br />
However, it is always problematic where these structures do not exist.<br />
At the initiative of the C<strong>en</strong>tral Committee we have arranged joined outings in which various branches participated<br />
and w<strong>en</strong>t as far as Pafuri in the Limpopo Province, Leshiba Wilderness, Nwanedi and Gundani in the Soutpansberg,<br />
St Lucia Lake in Kwa-Zulu Natal and Modikwa in the North West Province to name a few. As a valued member<br />
of the Society I urge every member to join in at any activity arranged by any branch, anywhere and to share<br />
your wonderful experi<strong>en</strong>ces with us. These will appreciatively be carried in either one of the newsletters or the<br />
D<strong>en</strong>dron.<br />
On behalf of the C<strong>en</strong>tral Committee I wish you all the timeless treasures of D<strong>en</strong>drology, the worth of home and the<br />
love of your family and above all the good <strong>co</strong>mpany of caring, true fri<strong>en</strong>ds during the festive season.<br />
Naas Grové<br />
Presid<strong>en</strong>t<br />
7<br />
DENDRON » No/Nr: 43 » November 2011
DENDRON » No/Nr: 43 » November 2011<br />
8<br />
dialogue<br />
dialoog<br />
Laat my net toe om julle <strong>van</strong> ons “ Boom “ op Gansbaai te vertel. Ons<br />
boom is `n Melkhoutboom (Sideroxylon inerme) geleë te Kerkstraat 27,<br />
Gansbaai <strong>en</strong> dit beslaan ongeveer e<strong>en</strong> derde <strong>van</strong> ons erf. ( 225m 2 )<br />
DIE BOOM GANSBAAI<br />
My Pa het <strong>die</strong> erf in 1988 gekoop na aanleiding <strong>van</strong> <strong>die</strong> volg<strong>en</strong>de<br />
gebeurt<strong>en</strong>is: Die vorige aand /nag het my Pa <strong>van</strong> ‘n groot boom<br />
gedroom <strong>en</strong> nadat hy <strong>die</strong> volg<strong>en</strong>de dag saam met my ma ‘n <strong>en</strong>t gaan<br />
stap het, het hulle <strong>die</strong> boom gewaar. Net daar <strong>en</strong> dan is daar toe<br />
besluit om hier<strong>die</strong> huis aan te koop. Die huisie was maar egter bitter<br />
klein, slegs 100m 2 , maar dit was <strong>die</strong> boom wat hom aangetrek het.<br />
Na <strong>die</strong> aankoop <strong>van</strong> <strong>die</strong> huis / boom het ons egter nog net pret onder<br />
<strong>die</strong> boom gehad. Daar is sedert 1988 elke jaar ‘n Kerspartytjie onder <strong>die</strong> boom gehou asook ons<br />
Nuwejaarspartytjies. Hier<strong>die</strong> boom is so groot dat dit maklik 60 m<strong>en</strong>se kan huisves.<br />
Ek ontmoet my vrou dan 10 jaar later onder <strong>die</strong>selfde boom <strong>en</strong> nadat ongeveer nog 6 jaar verloop, trou ons. Die<br />
boom is jaarliks <strong>die</strong> bymekaarkomplek <strong>van</strong> vri<strong>en</strong>de <strong>en</strong> familie. <strong>Jaar</strong>liks word daar ter ere <strong>van</strong> <strong>die</strong> boom ‘n CD<br />
vrygestel <strong>en</strong> sal dit <strong>die</strong> derti<strong>en</strong>de keer wees wat dit gebeur.<br />
Die boom is nie net vir ons spesiaal nie maar stories in Gansbaai do<strong>en</strong> <strong>die</strong> rondte dat <strong>die</strong> Vissermanne ook in <strong>die</strong><br />
verlede hulle jaareindfunksies daar gehou het. Daar word ook vertel <strong>van</strong> m<strong>en</strong>igte ander funksies wat onder hier<strong>die</strong><br />
boom gehou is.<br />
Die boom is vir ons ‘n gerieflike <strong>en</strong> gemaklike kuierplek <strong>en</strong> dit huisves onsett<strong>en</strong>d baie verskill<strong>en</strong>de voëlspesies <strong>en</strong><br />
party dae is dit sommer net lekker om onder <strong>die</strong> boom te sit <strong>en</strong> luister hoe <strong>die</strong> voëls in <strong>die</strong> takke baljaar.<br />
Die Gansbaai-boom is nie net onder <strong>die</strong> plaaslike geme<strong>en</strong>skap bek<strong>en</strong>d nie. Talle besoekers <strong>van</strong> Nederland,<br />
Frankryk <strong>en</strong> Kanada het al besoek by <strong>die</strong> boom afgelê <strong>en</strong> deel ons s<strong>en</strong>tim<strong>en</strong>t oor <strong>die</strong> plesier wat dit aan ons<br />
verskaf.<br />
Ek hoop <strong>en</strong> vertrou dat hier<strong>die</strong> skrywe julle sal kan laat verstaan <strong>die</strong> groot waardering wat ons vir hier<strong>die</strong> boom<br />
het <strong>en</strong> dat ons graag sal wil hê dat dit as ‘n spesiale boom registreer word nie net <strong>van</strong>weë sy grootte nie maar ook<br />
omdat dit vir ons so spesiaal is.<br />
Vri<strong>en</strong>delike Boomgroete<br />
Pieter Swart<br />
Redaksionele Komm<strong>en</strong>taar:<br />
Die Gansbaai-boom<br />
Pieter Swart - Gansbaai<br />
Pieter Swart het <strong>die</strong> boom onder ons aandag gebring na aanleiding <strong>van</strong> <strong>die</strong> Boompraatjies wat op RSG uitgesaai<br />
was. Die boom sal binnekort besoek word om opgemeet te word.<br />
dialogue<br />
dialoog<br />
9<br />
DENDRON » No/Nr: 43 » November 2011
THABAZIMBI SE GROOT KREMETART » Foto: Naas Grové<br />
tree stories<br />
boomstories<br />
Die Thabazimbi-bosveld se groot kremetart<br />
Die m<strong>en</strong>se <strong>van</strong> Leeupoort-vakansiedorp is lief vir<br />
<strong>die</strong> natuur. Die Koedoeskop omgewing bied<br />
oneindig veel, onder andere ’n ryk verskeid<strong>en</strong>heid <strong>van</strong><br />
inheemse bosveld bome. ‘n Groep natuurliefhebbers<br />
wat ’n besondere belangstelling in <strong>die</strong> omgewing se<br />
bome het, is <strong>die</strong> lede <strong>van</strong> <strong>die</strong> Kierieklappertak <strong>van</strong><br />
<strong>die</strong> D<strong>en</strong>drologiese Ver<strong>en</strong>iging <strong>van</strong> Suid-Afrika.Hier<strong>die</strong><br />
groep glo dat liefde vir <strong>die</strong> natuur word geskep<br />
deur k<strong>en</strong>nis <strong>van</strong> <strong>die</strong> natuur. Daarom poog hulle om<br />
elke tweede Wo<strong>en</strong>sdag <strong>van</strong> <strong>die</strong> maand iewers in <strong>die</strong><br />
omgewing te gaan stap, met <strong>die</strong> hoofdoel om meer<br />
te leer <strong>van</strong> bome. Dit is vebas<strong>en</strong>d hoeveel meer<br />
nuwe bome bygeleer word, maar ook hoeveel nuwe<br />
inligting oor reeds bek<strong>en</strong>de bome bekom word.<br />
Hier<strong>die</strong> groep het in Augustus 2010 besluit om besoek<br />
af te lê by <strong>die</strong> groot kremetart by Gannahoek. Die<br />
Augustus ogg<strong>en</strong>d lug was g<strong>en</strong>iepsig koud toe sewe<br />
voertuie <strong>en</strong> 22 opgewonde siele by Leeupoort se<br />
hek uitry. Die roete na Gannahoek neem hulle deur<br />
Vliegepoort verby Dwaalboom <strong>en</strong> anderkant <strong>die</strong><br />
Rooibokkraal grondpad is <strong>die</strong> ingang na Gannahoek<br />
Game Lodge. Die ei<strong>en</strong>aar Jean Taljaard on<strong>van</strong>g <strong>die</strong><br />
gaste hartlik <strong>en</strong> na so drie kilometer deur Acacia-veld,<br />
asof uit <strong>die</strong> niet veskyn <strong>die</strong> kolos <strong>van</strong> ’n bosveld reus<br />
voor hulle op.<br />
Die stilte is tasbaar <strong>en</strong> met <strong>die</strong> naderstap kan <strong>die</strong><br />
verstomming op almal se gesigte duidelik gesi<strong>en</strong><br />
word. Dit neem ’n aansi<strong>en</strong>like tyd om almal aan Jean<br />
voor te stel. Daar word onder mekaar vertel dat<br />
geleerdes me<strong>en</strong> <strong>die</strong> boom kan ‘n 1 000 jaar oud wees!<br />
Die kremetart (Adansonia digitata) is <strong>die</strong> aarde se<br />
grootse ‘vetplant’. Die g<strong>en</strong>usnaam Adansonia is<br />
ter ere <strong>van</strong> <strong>die</strong> Franse snydokter Michel Adanson<br />
(1727 – 1806) <strong>en</strong> digitata verwys na <strong>die</strong> handvormige<br />
saamgestelde blaar wat normaalweg uit vyf blaartjies<br />
bestaan. Die kremetart word in Afrika, meestal suid <strong>van</strong><br />
<strong>die</strong> Sahara aangetref. In Suid-Afrika is <strong>die</strong> natuurlike<br />
verspreiding beperk tot Mpumalanga <strong>en</strong> <strong>die</strong> Limpopo<br />
provinsies. Wat <strong>die</strong> spesifieke plant so uniek maak is<br />
dat dit waarskynlik <strong>die</strong> grootste natuurlike kremetart<br />
is wat <strong>die</strong> verste suid <strong>en</strong> wes in Suid-Afrika voorkom.<br />
Soos wat dit maar gaan met <strong>die</strong> geskied<strong>en</strong>is is daar<br />
ook vele staaltjies, leg<strong>en</strong>des <strong>en</strong> mites gekoppel aan<br />
<strong>die</strong> bestaan <strong>van</strong> <strong>die</strong> boom. Omdat <strong>die</strong> boom so<br />
geisoleerd <strong>en</strong> amper buite sy natuurlike verspreidings<br />
gebied voorkom, bestaan <strong>die</strong> leg<strong>en</strong>de dat <strong>die</strong><br />
oorspronklike saad afkomstig is uit K<strong>en</strong>ia. Dit sou hier<br />
beland het as gevolg <strong>van</strong> m<strong>en</strong>se wat vir <strong>die</strong> koningin<br />
<strong>van</strong> Skeba goud uit <strong>die</strong> Pilanesberg kom haal het!<br />
Hier<strong>die</strong> leg<strong>en</strong>de word versterk deur <strong>die</strong> storie dat<br />
Doep Du Plessis - Kierieklappertak<br />
<strong>die</strong>selfde koninging haar tin <strong>van</strong>af Leeupoort gekry<br />
het. Die mees logiese rede vir <strong>die</strong> verspreiding <strong>van</strong><br />
<strong>die</strong> saad is dat dit deur <strong>die</strong>re, soos olifante, geskied<br />
het.<br />
’n Ander leg<strong>en</strong>de wil hê dat <strong>die</strong> Boesmans<br />
verantwoordelik was vir <strong>die</strong> gat in <strong>die</strong> stam <strong>en</strong> dat<br />
hulle daarin sou skuil. Van <strong>die</strong> name wat op <strong>die</strong> stam<br />
uitgekerf is lyk nogal soos Boesman tek<strong>en</strong>inge.<br />
Tyd<strong>en</strong>s Paul Kruger se leeftyd – so word vertel, was<br />
hier<strong>die</strong> deel <strong>van</strong> <strong>die</strong> bosveld net in <strong>die</strong> winter besoek<br />
om te jag. Noord <strong>van</strong> Vliegepoort was tsetsevlieg<br />
gebied wat <strong>die</strong> wêreld ongeskik gemaak het vir<br />
boerdery. Dit is bek<strong>en</strong>d dat <strong>die</strong> ou Presid<strong>en</strong>t gereeld<br />
in <strong>die</strong> winter op <strong>die</strong> plaas Gannahoek gejag het <strong>en</strong><br />
onder <strong>die</strong> kremetart kamp opgeslaan het. Dit is ook<br />
tyd<strong>en</strong>s e<strong>en</strong> <strong>van</strong> <strong>die</strong> jagtogte dat sy hand vermink was<br />
in ’n ongeluk met ’n pangeweer.<br />
Aan <strong>die</strong> begin <strong>van</strong> <strong>die</strong> vorige eeu is daar begin om<br />
plase in <strong>die</strong> omgewing uit te meet. Omdat hier<strong>die</strong><br />
boom so ’n besondere bak<strong>en</strong> was het landmeters<br />
dit gereeld as verwysingspunt gebruik. Vuurpyle is<br />
<strong>van</strong>uit <strong>die</strong> kruin <strong>van</strong> <strong>die</strong> boom geskiet om hul posisies<br />
in plat bosveld te kon bepaal.<br />
Dit wil lyk asof <strong>die</strong> plaas Gannahoek aan Paul Kruger<br />
toegek<strong>en</strong> was, of aan e<strong>en</strong> <strong>van</strong> sy dogters of aan ’n <strong>en</strong>e<br />
Eloff wat met e<strong>en</strong> <strong>van</strong> sy dogters getroud was. ’n Dr. de<br />
Ridder is weer met e<strong>en</strong> <strong>van</strong> Eloff se dogters getroud<br />
<strong>en</strong> klein Rob <strong>van</strong> R<strong>en</strong>sburg trou toe met ’n dogter <strong>van</strong><br />
De Ridder. Gedur<strong>en</strong>de dié jare was <strong>die</strong> kremetart<br />
boom ’n gewilde bymekaar komplek. Dit is dan ook<br />
nie vreemd nie dat posstukke afkomstig uit Botswana<br />
hier gelaat is om afgehaal te word uit Pretoria. Baie <strong>van</strong><br />
<strong>die</strong> groep wat <strong>die</strong> boom dié dag besoek het, het in <strong>die</strong><br />
omgewing groot geword. So word vertel dat Geloftefeeste<br />
hier gehou was. Politieke partye het hul stryd<br />
in <strong>die</strong> skadu <strong>van</strong> <strong>die</strong> boom gevoer. ’n Ander ou vertel<br />
<strong>van</strong> jukskei wat hier gespeel was <strong>en</strong> hoe jong kinders<br />
wegkruipertjie in <strong>die</strong> boom gespeel het. As <strong>die</strong> boom<br />
kon praat, wat sou hy ons vertel het?<br />
Almal het met groot ontsag om <strong>die</strong> boom beweeg,<br />
dit aangeraak, <strong>en</strong> <strong>die</strong> name wat op <strong>die</strong> stam uitgekerf<br />
is probeer ontrafel. Die baie kartels <strong>en</strong> plooie in <strong>die</strong><br />
stam herinner ’n m<strong>en</strong>s aldeur aan ouderdom. By <strong>die</strong><br />
bek <strong>van</strong> <strong>die</strong> gat in <strong>die</strong> stam soek ek na ’n patroon<br />
doppie wat ek 40 jaar gelede daar gesi<strong>en</strong> het. Dit is<br />
nog steeds daar asof dit gister daar ingeslaan was.<br />
Dit is ’n indrukwekk<strong>en</strong>de boom <strong>en</strong> <strong>van</strong> <strong>die</strong> waarnemings<br />
wat gemaak is, is <strong>die</strong> volg<strong>en</strong>de:<br />
11<br />
DENDRON » No/Nr: 43 » November 2011
DENDRON » No/Nr: 43 » November 2011<br />
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tree stories<br />
boomstories<br />
DIE THABAZIMBI-BOSVELD SE GROOT KREMETART<br />
• Daar is baie bogrondse wortels, sommige 20m<br />
lank. Het dit iets te make met <strong>die</strong> grond tipe?<br />
• Dit het nege mans wat hande vat g<strong>en</strong>eem om <strong>die</strong><br />
boom te omsingel.<br />
• Die te<strong>en</strong>woordigheid <strong>van</strong> vlermuise is duidelik<br />
aan <strong>die</strong> hoeveelheid vlermuis mis wat in <strong>die</strong> gat<br />
in <strong>die</strong> stam voorkom. Vlermuise is onder andere<br />
verantwoordelik vir <strong>die</strong> bestuiwing <strong>van</strong> <strong>die</strong><br />
blomme <strong>van</strong> <strong>die</strong> plant.<br />
• Daar is opvall<strong>en</strong>d baie name op <strong>die</strong> stam<br />
uitgekerf. Sommige datums dateer 100 terug.<br />
Paul Kruger se voorletters is uitk<strong>en</strong>baar saam<br />
met talle ander, wat ’n aanduiding is dat <strong>die</strong><br />
boom deur baie m<strong>en</strong>se besoek was. Saam met<br />
<strong>die</strong> groei <strong>van</strong> <strong>die</strong> boom het <strong>die</strong> name ook al hoër<br />
te<strong>en</strong> <strong>die</strong> stam opgeskuif.<br />
• Veertig jaar gelede was <strong>die</strong> bek <strong>van</strong> <strong>die</strong> gat in<br />
<strong>die</strong> stam so groot dat ’n volwasse man daar kon<br />
inklim. Dit is nou so klein dat slegs ’n jong kind dit<br />
sal regkry.<br />
• Bo in <strong>die</strong> takke is daar oorblyfsels <strong>van</strong> voël neste.<br />
Jean vertel dat bruinslangar<strong>en</strong>de gereeld in<br />
<strong>die</strong> boom kom broei. Dit verklaar dan ook <strong>die</strong><br />
slangvel reste wat hoog in <strong>die</strong> takke hang.<br />
• Oorblyfsels <strong>van</strong> blomme e<strong>en</strong> vrugte is onder <strong>die</strong><br />
boom gevind wat bevestiging is dat <strong>die</strong> vlermuise<br />
hul werk do<strong>en</strong>.<br />
INSKRIPSIES OP DIE STAM » Foto: Naas Grové<br />
Dit is voorwaar ’n indrukwekk<strong>en</strong>de boom <strong>en</strong> het dit <strong>die</strong> groep<br />
twee ure g<strong>en</strong>eem om fotos te neem, <strong>die</strong> te<strong>en</strong>woordigheid <strong>van</strong><br />
<strong>die</strong> kolos in te adem <strong>en</strong> om afskeid te neem.<br />
OU BEN VAN GANNAHOEK, wat sy eie storie het om te vertel » Foto: Naas Grové<br />
J.A. Schoonees vra in sy brief <strong>van</strong> 23 Desember of sy<br />
kremetart in Pretoria <strong>die</strong> verste suid in Afrika is.<br />
By wyle g<strong>en</strong>l. Van der Spuy se plaasopstal, ‘n paar<br />
kilometer suid <strong>van</strong> <strong>die</strong> Wit Umfolozi-rivier langs <strong>die</strong> pad<br />
tuss<strong>en</strong> Ulundi <strong>en</strong> Melmoth, is ‘n kremetart aangeplant. In<br />
<strong>die</strong> sew<strong>en</strong>tigerjare, toe ek by Ulundi werksaam was, was<br />
<strong>die</strong> kremetart al ‘n skotige 4 m hoog.<br />
Die suidelikste natuurlike kremetartboom waar<strong>van</strong> ek weet,<br />
is <strong>die</strong> e<strong>en</strong> op <strong>die</strong> plaas Gannahoek tuss<strong>en</strong> Thabazimbi <strong>en</strong><br />
Makoppa in <strong>die</strong> Thabazimbi-distrik.<br />
Dat hier ‘n natuurlike e<strong>en</strong> gegroei het, is self snaaks, want<br />
daar is nie ander naby nie <strong>en</strong> hulle is nie alle<strong>en</strong>loper-bome<br />
nie. Hoe <strong>die</strong> moederpit daar gekom het, kan m<strong>en</strong>s maar<br />
raai. ‘n Olifant wat baie ver langs <strong>die</strong> Limpopo op geloop<br />
het, is <strong>die</strong> <strong>en</strong>igste moontlike draer waaraan ek kan dink.<br />
Pres. Paul Kruger het glo ‘n winter of twee by <strong>die</strong> kremetart<br />
sy jagkamp opgeslaan.<br />
Bron:<br />
http://152.111.1.88/argief/berigte/beeld/2002/12/24/8/3.html<br />
DIE THABAZIMBI-BOSVELD SE GROOT KREMETART<br />
Briewe uit <strong>die</strong> argiewe<br />
Dié kremetart is <strong>die</strong> verste suid<br />
Paul Fouche - Modimolle (Nylstroom)<br />
tree stories<br />
boomstories<br />
?<br />
13<br />
DENDRON » No/Nr: 43 » November 2011
DENDRON » No/Nr: 43 » November 2011<br />
14<br />
tree stories<br />
boomstories<br />
KOMMENTAAR OOR DIE GROOT KREMETART VAN GANNAHOEK<br />
Komm<strong>en</strong>taar oor <strong>die</strong> groot kremetart <strong>van</strong> Gannahoek<br />
Die groot kremetart <strong>van</strong> Gannahoek naby Makoppa in<br />
<strong>die</strong> Thabazimbi-distrik trek reeds vir jare <strong>die</strong> aandag,<br />
nie alle<strong>en</strong> we<strong>en</strong>s sy ooglop<strong>en</strong>d hoë ouderdom nie,<br />
maar veral omdat dit <strong>die</strong> <strong>en</strong>igste <strong>van</strong> sy soort in<br />
daar<strong>die</strong> omgewing is <strong>en</strong> we<strong>en</strong>s <strong>die</strong> talle leg<strong>en</strong>des<br />
<strong>en</strong> staaltjies daarom he<strong>en</strong>. Daar is ook al beweer dat<br />
dit <strong>die</strong> kremetart met <strong>die</strong> mees suidelike natuurlike<br />
verspreiding in Afrika is.<br />
Is <strong>die</strong> Gannahoek-verspreiding by 24˚ 26’ 16.7’’<br />
Suid buit<strong>en</strong>gewoon vir ‘n kremetart?<br />
Gannahoek se kremetart is naby <strong>die</strong> suidelikste gr<strong>en</strong>s<br />
<strong>van</strong> <strong>die</strong> spesie se verspreiding in Afrika. Maar dit is nie<br />
<strong>die</strong> mees suidelike natuurlike boom <strong>van</strong> dié spesie<br />
op <strong>die</strong> kontin<strong>en</strong>t nie. Dié status behoort waarskynlik<br />
aan ‘n kremetart in <strong>die</strong> Nasionale Krugerwildtuin of<br />
Mosambiek. Daar staan byvoorbeeld in <strong>die</strong> wildtuin<br />
‘n boom wat vir toeriste toeganklik is by 24˚ 37’ 6.29”<br />
Suid. Alhoewel dit met <strong>die</strong> eerste oogopslag lyk of <strong>die</strong><br />
Gannahoekboom wat verspreiding betref ‘n uitskieter is<br />
wat buite <strong>die</strong> spesie se natuurlike verspreidingsgebied<br />
groei, is dit nie <strong>die</strong> geval nie. Net wes <strong>van</strong> Gannahoek<br />
<strong>en</strong> op byna <strong>die</strong>selfde breedtegraad in Botswana groei<br />
daar kremetarte by Mochudi. Laasg<strong>en</strong>oemde is na<br />
bewering <strong>die</strong> suidelikste natuurlike verspreiding in<br />
Botswana. Elders in <strong>die</strong> Waterberg is daar <strong>en</strong>kele<br />
kremetarte noordoos <strong>van</strong> Gannahoek in onder<br />
andere <strong>die</strong> Lapalala-wildernisgebied. Die naaste<br />
hoofverspreidingsgebied <strong>van</strong> <strong>die</strong> kremetart is egter<br />
verder noord in <strong>die</strong> Limpopovallei, veral agter <strong>die</strong><br />
Soutpansberg. In <strong>die</strong> meegaande bydrae word<br />
g<strong>en</strong>oem dat <strong>die</strong> Gannahoekkremetart <strong>die</strong> grootste<br />
natuurlike boom <strong>van</strong> sy soort is wat <strong>die</strong> verste wes (by<br />
27˚ 08’ 46.7” Oos) in Suid-Afrika voorkom. Die stelling<br />
blyk korrek te wees.<br />
Hoe word <strong>die</strong> geïsoleerde voorkoms <strong>van</strong> <strong>die</strong><br />
Gannahoekboom verklaar?<br />
Die boom by Gannahoek is óf <strong>die</strong> laaste oorblyw<strong>en</strong>de<br />
lid <strong>van</strong> kremetartbevolkings wat vroeër in daar<strong>die</strong><br />
gebied gegroei het, óf dit het daar beland nadat ‘n<br />
saad deur langafstandverspreiding ver weg <strong>van</strong> <strong>die</strong><br />
moederboom suksesvol ontkiem <strong>en</strong> gevestig het.<br />
Dit is bek<strong>en</strong>d dat <strong>die</strong> verspreiding <strong>van</strong> plantspesies<br />
oor tyd verander in oore<strong>en</strong>stemming met veral<br />
natuurlike klimaatsveranderinge. So byvoorbeeld is<br />
daar al stuifmeel <strong>van</strong> bosveldbome in afsettinge in<br />
<strong>die</strong> Waterberg gevind wat tans nie meer natuurlik in<br />
<strong>die</strong> gebied voorkom nie. Dit is nie onmoontlik dat <strong>die</strong><br />
Prof. Braam <strong>van</strong> Wyk<br />
kremetart by tye in <strong>die</strong> verlede in groter getalle verder<br />
suid as tans gegroei het nie. In sodanige geval sou <strong>die</strong><br />
boom by Gannahoek ‘n reliek uit ‘n vervloë tyd wees.<br />
‘n Meer waarskynlike verklaring is dat<br />
<strong>die</strong> Gannahoekboom gevestig het na<br />
langafstandsaadverspreiding. Die geskied<strong>en</strong>is <strong>van</strong><br />
<strong>die</strong> m<strong>en</strong>s is nou verweef met <strong>die</strong> verspreiding <strong>van</strong><br />
baie plantsoorte in Afrika. Die m<strong>en</strong>s is nie alle<strong>en</strong><br />
inheems in Afrika nie, maar dit is bek<strong>en</strong>d dat hy<br />
in historiese tye ‘n aktiewe rol gespeel het in <strong>die</strong><br />
verspreiding <strong>van</strong> baie boomsoorte op <strong>die</strong> kontin<strong>en</strong>t.<br />
In <strong>die</strong> opsig is <strong>die</strong> kremetart ‘n bek<strong>en</strong>de voorbeeld.<br />
Verspreidings waarby <strong>die</strong> m<strong>en</strong>s betrokke was is<br />
dikwels met argeologiese terreine geassosieer. Dit<br />
sal insiggew<strong>en</strong>d wees om uit te kyk vir moontlike<br />
argeologiese tek<strong>en</strong>s <strong>van</strong> m<strong>en</strong>slike aktiwiteit in <strong>die</strong><br />
omgewing <strong>van</strong> <strong>die</strong> Gannahoekboom.<br />
Die leg<strong>en</strong>de dat saad <strong>van</strong> <strong>die</strong><br />
Gannahoekboom deur <strong>die</strong> m<strong>en</strong>s <strong>van</strong> sover weg as<br />
K<strong>en</strong>ia na sy huidige groeiplek gebring is, is alhoewel<br />
nie onmoontlik nie, hoogs onwaarskynlik. Daar is<br />
soveel ander kremetartbome nader aan Gannahoek<br />
waar<strong>van</strong>daan saad veel makliker kon gekom het. Die<br />
kremetart toon groot g<strong>en</strong>etiese variasie in verskill<strong>en</strong>de<br />
dele <strong>van</strong> Afrika, tot so ‘n mate dat daar al voorstelle was<br />
om dit in verskill<strong>en</strong>de spesies te onderverdeel. Veral<br />
<strong>die</strong> vorm <strong>van</strong> <strong>die</strong> vrugte toon groot streeksvariasie.<br />
Dit sal sekerlik moontlik wees om met gesofistikeerde<br />
DNS-tegnieke <strong>die</strong> naaste verwante <strong>van</strong> <strong>die</strong><br />
Gannahoekboom te bepaal, of t<strong>en</strong> minste ‘n beweerde<br />
Oos-Afrika verbint<strong>en</strong>is uit te skakel of te bevestig. In<br />
<strong>die</strong> verband is dit interessant dat <strong>die</strong> onderbroke<br />
verspreiding <strong>van</strong> ‘n ander bosveldboom, <strong>die</strong> veel<br />
skaarser bosveldrooiklapperbos (Erythrophysa<br />
transvaal<strong>en</strong>sis), ook al gekoppel is aan bewegings<br />
<strong>van</strong> <strong>die</strong> m<strong>en</strong>s tuss<strong>en</strong> plekke waar in antieke tye onder<br />
andere vir tin gemyn is in Suid-Afrika <strong>en</strong> Zimbabwe.<br />
Saad <strong>van</strong> <strong>die</strong> spesie is vermoedelik deur <strong>die</strong> m<strong>en</strong>se<br />
as krale gebruik.<br />
Kremetartsaad is bestand te<strong>en</strong> uitdroging,<br />
bly lank kiemkragtig <strong>en</strong> kan pot<strong>en</strong>sieel oor lang<br />
afstande versprei. Dit het ook ‘n harde saadhuid (is<br />
sog<strong>en</strong>aamd hardskalig) <strong>en</strong> ontkiem beter nadat dit<br />
deur <strong>die</strong> spysverteringskanaal <strong>van</strong> ‘n <strong>die</strong>r gegaan het.<br />
B<strong>en</strong>ew<strong>en</strong>s <strong>die</strong> m<strong>en</strong>s kon verskeie ander <strong>die</strong>re ‘n rol<br />
by <strong>die</strong> inbring <strong>van</strong> <strong>die</strong> Gannahoekboom se saad <strong>van</strong><br />
iewers elders gespeel het. Moontlike saadverspreiders<br />
oor langer afstande sluit in <strong>die</strong> olifant, swartr<strong>en</strong>oster <strong>en</strong><br />
sekere boksoorte, byvoorbeeld <strong>die</strong> eland. Bobbejane<br />
versprei <strong>die</strong> saad in hul mis <strong>en</strong> speel ‘n belangrike rol<br />
om kremetarte oor veral korter afstande te versprei.<br />
Min is bek<strong>en</strong>d oor <strong>die</strong> verspreiding <strong>van</strong> kremetartsaad<br />
deur voëls (byvoorbeeld neushoringvoëls <strong>en</strong><br />
bosveldpapegaaie), maar dit is beslis ook ‘n<br />
moontlikheid.<br />
Waarom is daar slegs ‘n <strong>en</strong>kele kremetartboom<br />
by Gannahoek?<br />
Die feit dat daar in <strong>die</strong> omgewing <strong>van</strong> Gannahoek<br />
nie ‘n bevolking <strong>van</strong> kremetarte is soos wat m<strong>en</strong>s<br />
sou verwag nie, is ongewoon. Dit mag onder andere<br />
daarop dui dat huidige omgewingstoestande nie<br />
meer gunstig is vir <strong>die</strong> natuurlike vestiging <strong>van</strong><br />
kremetartsaailinge in <strong>die</strong> betrokke omgewing nie. So<br />
iets sou m<strong>en</strong>s verwag indi<strong>en</strong> <strong>die</strong> boom inderdaad ‘n<br />
reliek is wat uit ‘n tydperk dateer toe <strong>die</strong> gebied se<br />
klimaat anders was as wat dit tans is.<br />
‘n Sleutelvraag is of <strong>die</strong> Gannahoekboom vrugte<br />
dra <strong>en</strong> indi<strong>en</strong> wel, of hulle kiemkragtige saad bevat.<br />
Bestuiwing by <strong>die</strong> kremetart word bewerkstellig deur<br />
veral vrugtevlermuise, maar ook nagapies <strong>en</strong> verskeie<br />
soorte insekte. Dit kan aanvaar word dat bestuiwing<br />
<strong>van</strong> <strong>die</strong> Gannahoekboom se blomme nie ‘n probleem<br />
behoort te wees nie.<br />
Ondanks <strong>die</strong> feit dat <strong>die</strong> kremetart e<strong>en</strong> <strong>van</strong> <strong>die</strong> mees<br />
bestudeerde bome in Afrika is, is daar nog onsekerhede<br />
oor aspekte <strong>van</strong> sy voortplantingsbiologie. Daar word<br />
Stu<strong>die</strong>s het aangetoon dat <strong>die</strong> gemiddelde<br />
to<strong>en</strong>ame in groei in omtrek <strong>van</strong> ‘n kremetartboom<br />
in <strong>die</strong> Zambesi vallei kan wissel <strong>van</strong> 0.15cm - ±<br />
0.75cm / jaar was te<strong>en</strong>oor <strong>die</strong> 0.01cm / jaar in <strong>die</strong><br />
Limpopovallei. (Guy, G. L. 1970. Adansonia digitata<br />
and its rate of growth in relation to rainfall in South<br />
C<strong>en</strong>tral Africa. Proceedings Transactions Rhodesia<br />
Sci<strong>en</strong>tific Association 54 (2) 69-84).<br />
Sodra kremetartbome ouer word verminder <strong>die</strong><br />
groeitempo <strong>en</strong> kan hulle ‘krimp’ as gevolg <strong>van</strong><br />
hidroskopiese kondisies. Veranderinge is ook meer<br />
drasties as <strong>die</strong> boom vol blare is <strong>en</strong> <strong>van</strong>selfsprek<strong>en</strong>d<br />
speel <strong>die</strong> 40% water inhoud in <strong>die</strong> stam ook ‘n rol in<br />
<strong>die</strong> bepaling <strong>van</strong> <strong>die</strong> werklike stam omtrek <strong>van</strong> <strong>die</strong><br />
boom. (F<strong>en</strong>ner, M. 1980. Some measurem<strong>en</strong>ts on<br />
the water relations of baobab trees. Biotropica 12(3):<br />
205-209). So byvoorbeeld is ‘n kremetart boom wat in<br />
1946 opgemeet is 60 cm dunner gewees as wat dit in<br />
1931 was! (Esterhuyse et al. 2001)<br />
KOMMENTAAR OOR DIE GROOT KREMETART VAN GANNAHOEK<br />
Redaksionele Komm<strong>en</strong>taar<br />
tree stories<br />
boomstories<br />
byvoorbeeld steeds gespekuleer of ‘n kremetart<br />
na bestuiwing met sy eie stuifmeel vrugbare saad<br />
kan vorm al dan nie, met ander woorde is <strong>die</strong> boom<br />
selfver<strong>en</strong>igbaar of selfonver<strong>en</strong>igbaar. Die aanduidings<br />
is dat stuifmeel <strong>van</strong> ‘n ander boom nodig is om vrugbare<br />
saad te vorm, met ander woorde <strong>die</strong> kremetart is<br />
selfonver<strong>en</strong>igbaar <strong>en</strong> b<strong>en</strong>odig kruisbestuiwing.<br />
Maar dit is nie so e<strong>en</strong>voudig nie. Dit wil voorkom<br />
asof kremetarte wat buite hul natuurlike<br />
verspreidingsgebied aangeplant is na selfbestuiwing<br />
wel vrugte met saad vorm, maar dat <strong>die</strong> embrio op<br />
‘n vroeë stadium aborteer <strong>en</strong> dat <strong>die</strong> saad gevolglik<br />
nie kiemkragtig is nie, ‘n verskynsel bek<strong>en</strong>d as laatselfonver<strong>en</strong>igbaarheid.<br />
Indi<strong>en</strong> kruisbestuiwing tuss<strong>en</strong><br />
verskill<strong>en</strong>de bome nodig is, dan kan <strong>die</strong> gebrek aan<br />
ander kremetartbome in sy omgewing ‘n verklaring<br />
bied vir <strong>die</strong> <strong>en</strong>kele boom by Gannahoek.<br />
Volg<strong>en</strong>s <strong>die</strong> meegaande bydrae blyk dit dat <strong>die</strong><br />
Gannahoekboom wel vrugte dra. Dit sal insiggew<strong>en</strong>d<br />
wees om vas te stel of <strong>die</strong> saad in <strong>die</strong> vrugte normaal<br />
ontwikkel het <strong>en</strong> kiemkragtig is. Waarnemings op<br />
hier<strong>die</strong> boom kan dalk help om <strong>die</strong> onsekerheid of<br />
kruisbestuiwing noodsaaklik is vir <strong>die</strong> suksesvolle<br />
voortplanting <strong>van</strong> <strong>die</strong> kremetart uit <strong>die</strong> weg te ruim.<br />
Sulke waarnemings sal natuurlik slegs betek<strong>en</strong>isvol<br />
wees indi<strong>en</strong> daar ge<strong>en</strong> aangeplante kremetarte is wat<br />
in tuine in <strong>die</strong> omgewing <strong>van</strong> <strong>die</strong> Gannahoekboom<br />
blom nie.<br />
Gebaseer op Guy (1970) se aanname dat <strong>die</strong><br />
kremetartboom te<strong>en</strong> ‘n tempo <strong>van</strong> 0.75cm / jaar in<br />
omtrek groei, kan kremetartbome se ouderdom<br />
rofweg bepaal word deur <strong>die</strong> volg<strong>en</strong>de formule te<br />
gebruik: (Barnes, R.F.W. 1983. Effects of elephant<br />
browsing on woodlands in a Tan<strong>za</strong>nian National Park:<br />
Measurem<strong>en</strong>ts, models and managem<strong>en</strong>t. Journal of<br />
Applied E<strong>co</strong>logy 20: 521-540.)<br />
Ouderdom in jare = 0.213 X stam omtrek in cm<br />
Indi<strong>en</strong> hier<strong>die</strong> formule op <strong>die</strong> Gannahoek-boom<br />
toegepas word is <strong>die</strong> boom ongeveer 255 jaar oud.<br />
Terselfdertyd sou <strong>die</strong> Sagole-boom naby Tshipise ±<br />
698 jaar oud wees.<br />
Die wêreld se ‘vetsugtigste’ boom is <strong>die</strong> Taxodium<br />
mucronatum (Mexican Bald Cypress) met ‘n omtrek<br />
<strong>van</strong> 57.9m, ‘n deursnee <strong>van</strong> 18.4m, hoogte <strong>van</strong> 41.85m<br />
<strong>en</strong> <strong>die</strong> waarskynlike ouderdom is ± 1 230 jaar. Die<br />
boom groei in ‘n begraafplaas naby <strong>die</strong> dorpie Maria<br />
del Tule in Oaxaca, Mexiko. (Esterhuyse et al. 2001).<br />
15<br />
DENDRON » No/Nr: 43 » November 2011
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16<br />
The partners in the v<strong>en</strong>ture » Leon Visser (climber) and Brof Brian Bred<strong>en</strong>kamp (ground crew) at the base of the tallest tree in Africa.<br />
The twins that became triplets.<br />
The weather in the Boland was near-perfect early<br />
last week, but in the forest areas of Limpopo it was<br />
so bad that two of South Africa’s four Albatross aircraft<br />
flew into the side of a mountain. While rescue parties<br />
were looking for the crash site, two foresters from<br />
Stell<strong>en</strong>bosch, Brian Bred<strong>en</strong>kamp and Leon Visser<br />
were in the rain in the plantations of Magoebaskloof,<br />
measuring trees. Brian is Emeritus Professor of Forest<br />
Managem<strong>en</strong>t at the University of Stell<strong>en</strong>bosch and<br />
serves on the Minister of Forestry’s advisory panel<br />
for the National Champion Tree Project while Leon<br />
is an arborist and owner of Trees Unlimited. He is<br />
passionate about climbing trees. There is a synergy<br />
with the former’s expertise in forest m<strong>en</strong>suration and<br />
the hobby of the latter. Leon climbs the tallest trees<br />
in the <strong>co</strong>untry and drops a tape to his ground crew,<br />
Brian, who th<strong>en</strong> re<strong>co</strong>rds the height. As Brian jokingly<br />
puts it; Leon merely holds the <strong>en</strong>d of the tape while he<br />
measures the tree.<br />
Local foresters on Woodbush Forest had dis<strong>co</strong>vered<br />
three huge Mexican yellow pines (Pinus oocarpa)<br />
that had be<strong>en</strong> planted in 1905 and left wh<strong>en</strong> the rest<br />
of the stand was clearfelled some sev<strong>en</strong>ty years ago.<br />
The stand had not be<strong>en</strong> replanted and these three<br />
now tower above the indig<strong>en</strong>ous forest that has reestablished<br />
itself. The trees had be<strong>en</strong> reported to<br />
the Departm<strong>en</strong>t of Forestry and the responsible<br />
official had asked Stihl (South Africa) to sponsor the<br />
measurem<strong>en</strong>t of the trees. Stihl had kindly agreed<br />
to <strong>co</strong>ver the travel exp<strong>en</strong>ses of Brian and Leon who<br />
flew to Johannesburg and th<strong>en</strong> travelled by road to<br />
Magoebaskloof, via Polokwane, on Sunday morning.<br />
By nightfall the first of the three trees had already<br />
be<strong>en</strong> climbed and measured and the throw lines were<br />
already in the crown of the se<strong>co</strong>nd.<br />
On Monday morning Leon was up the 50 m tree in<br />
less than an hour despite the pelting rain and before<br />
lunch the objectives of the trip had be<strong>en</strong> met. The<br />
trees had be<strong>en</strong> measured and had be<strong>en</strong> dubbed the<br />
Matrons of Magoebaskloof. However, this provided an<br />
opportunity!<br />
The Matrons were only a short walk from the Twin<br />
Giants of Magoebaskloof. These were two Sydney<br />
I<strong>za</strong>k <strong>van</strong> der Merwe<br />
THE TWINS THAT BECAME TRIPLETS.<br />
blue gums (Eucalyptus saligna) that Leon had climbed<br />
and Brian had measured the year before. They were<br />
78,5 and 79,0 m tall and were not only the tallest trees<br />
on the African <strong>co</strong>ntin<strong>en</strong>t, they were the tallest planted<br />
Eucalypts in the world. They had be<strong>en</strong> id<strong>en</strong>tified for<br />
climbing from satellite imagery and wh<strong>en</strong> Leon was<br />
up in the crowns he’d se<strong>en</strong> another tree, mere metres<br />
away, that he suspected was ev<strong>en</strong> taller. However, by<br />
that time it was already dark on the forest floor and<br />
there had not be<strong>en</strong> an opportunity to climb the tree.<br />
Now that opportunity had arrived.<br />
Opportunity might not be the best word, of <strong>co</strong>urse. Most<br />
of the day was available but it was raining <strong>co</strong>ntinuously<br />
and the bark of a gum tree is a lot smoother than that of<br />
a pine tree. It would be dangerous to climb in the rain<br />
because as the roadsigns proclaim; Slippery wh<strong>en</strong><br />
wet! Undeterred, Leon set off. The lowest live branch<br />
was more than 30 m above the ground and it took a<br />
while before it was possible to shoot a lead weight<br />
with an attached throw-line over it. The climbing rope<br />
was pulled over the branch by means of the throw line<br />
and th<strong>en</strong> Leon set off, ankle-locking his way up the<br />
rope. It took another 15 passes to higher branches<br />
and two hours before he reached the top and Brian<br />
attached the <strong>en</strong>d of the tape measure to the climbing<br />
rope. Leon th<strong>en</strong> pulled the <strong>en</strong>d of the tape to the<br />
top of the tree and Brian read the height: 80 m! The<br />
tree is now the tallest known in Africa. There are now<br />
three giant trees in the grove and the Twin Giants of<br />
Magoebaskloof now became the Triplet Giants of<br />
Magoebaskloof.<br />
It may be useful to think about what a height of 80<br />
m implies. Were the tree to stand on the quarter<br />
line of the All Blacks and fall toward the Springbok<br />
line it would flatt<strong>en</strong> the posts! The tallest tree in<br />
Stell<strong>en</strong>bosch, possibly in the Boland, in Helsehoogte, a<br />
sugar gum next to the old Helshoogte Pass, and that is<br />
a mere 54 m tall. Arguably the most promin<strong>en</strong>t tree in<br />
Stell<strong>en</strong>bosch is the almost 200-year old Norfolk Island<br />
Pine in front of the Theological Seminary, a tree that is<br />
taller than the steeple of the Moederkerk. The new<br />
Triplet is almost twice as tall!<br />
tree stories<br />
boomstories<br />
17<br />
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18<br />
tree stories<br />
boomstories<br />
TREE SURVEY IN SEKHUKHUNELAND<br />
Tree Survey in Sekhukhuneland<br />
Over the week-<strong>en</strong>d of 4 to 6 February 2011 a<br />
group of members from several branches of the<br />
D<strong>en</strong>drological Society were privileged to join experts<br />
and delegates from various other Societies to <strong>co</strong>nduct<br />
a survey of the trees and vegetation in the area of<br />
the Tšate Provincial Heritage site in the Sekhukhune<br />
C<strong>en</strong>tre of Plant Endemism. We visited here at the<br />
invitation of Li<strong>za</strong>nne Nel, who is facilitating a project for<br />
the Sekhukhune District Municipality, but more about<br />
that a little later.<br />
On preparing for the survey, I realised that I knew but<br />
little about this area and started wondering as to what<br />
its possible claim to fame <strong>co</strong>uld be. It turns out that the<br />
area is very interesting and in many respects unique.<br />
Where is Sekhukhuneland?<br />
Sekhukhuneland is located within the area bordered<br />
by the Olifants River in the west, the Strydpoort<br />
Mountains in the north, and the Steelpoort River<br />
in the east. It is the land occupied by the Pedi<br />
people, the Bapedi, who belong to the Northern<br />
Sotho linguistic group. In the past, the Pedi had a<br />
much larger territory, occupying the area betwe<strong>en</strong><br />
Rust<strong>en</strong>burg in the west, the Vaal River to the south,<br />
and the lowveld in the east.<br />
Hartwig von Dürckheim<br />
Some Historical Background.<br />
The ev<strong>en</strong>ing of our arrival, and around a lively<br />
campfire, Li<strong>za</strong>nne briefly sketched the interesting<br />
history of the area and its people.<br />
The earliest settlers in the region appear to have be<strong>en</strong><br />
farming <strong>co</strong>mmunities who established themselves<br />
south of the Limpopo river around 200 AD. These<br />
mark the beginning of the South African Iron Age<br />
period. Some rich archaeological finds of Iron Age<br />
sites in the area of the Tšate Valley are testimony to the<br />
activities of these early people who, it is presumed,<br />
may have be<strong>en</strong> related to the Middle Iron Age culture<br />
of Mapungubwe. These early people were displaced<br />
by the migration of people from C<strong>en</strong>tral Africa.<br />
The Sotho people appear to have migrated<br />
southward in successive waves from the Great Lakes<br />
region in C<strong>en</strong>tral Africa as from about 1500 AD, and<br />
one of these groups settled in the Western Transvaal<br />
around 1650. Parts of this tribe later moved to<br />
the vicinity of what is today Pretoria. Strife and<br />
<strong>co</strong>mpetition led to a section of that group to move<br />
east and settle in the Steelpoort area, where the Pedi<br />
nation was th<strong>en</strong> established. By 1800 Thulare was<br />
the leader of the Pedi Empire in the north-eastern<br />
Transvaal. The Pedi th<strong>en</strong> <strong>co</strong>nsisted of several tribes,<br />
who <strong>en</strong>joyed great wealth under Thulare’s rule and<br />
he is still honoured as a great chief and leader to<br />
this day. Th<strong>en</strong> followed the chaos of the Difaqane<br />
wars (about 1815 to 1836) where the Zulus under<br />
their king Skaka, and later Mzilikazi, laid to waste<br />
and dispersed the tribes that had settled in the<br />
Transvaal. Thulare’s son Sekwati was th<strong>en</strong> the leader,<br />
and he fled with the Pedi to the north where he took<br />
refuge. Some years later he returned and settled in<br />
the area known as Magali’s Location. Sekwati’s son<br />
and successor, Sekhukhune, initially <strong>co</strong>nsolidated<br />
the power of the Pedi, but years of drought and a<br />
series of attacks from the South African Republic and<br />
the Swazi chiefdom weak<strong>en</strong>ed the Pedi during the<br />
1870s. Around 1845 the Voortrekkers under H<strong>en</strong>drik<br />
Pogieter settled at Ohrigstad and <strong>co</strong>ncluded<br />
a treaty with the Pedi. In spite of the treaty, cattle<br />
thefts and labour disputes occurred and this caused<br />
friction betwe<strong>en</strong> the Voortrekkers and the Pedi. This<br />
situation deteriorated for many years until in 1876<br />
the Voortrekkers waged war on the Pedi under<br />
Sekhukhune, but were defeated and had to retire.<br />
TREE SURVEY IN SEKHUKHUNELAND<br />
Confrontation <strong>co</strong>ntinued until the British annexed<br />
the Transvaal in April 1877.<br />
tree stories<br />
boomstories<br />
In 1878 the Bapedi were at war once more, this<br />
time with the British under Theophilus Shepstone<br />
who viewed Sekhukhune as a hindrance to British<br />
ambitions in the Transvaal. Several in<strong>co</strong>nclusive<br />
battles were fought until November 1879 wh<strong>en</strong>, in<br />
an expedition led by Col Baker Russel, 3 500 British<br />
regular troops and 3 000 Transvaal levies <strong>co</strong>mbined<br />
forces with 8 000 Swazi warriors to defeat the Pedi. In<br />
a battle lasting five hours the Pedi were <strong>van</strong>quished<br />
and Sekhukhune was subsequ<strong>en</strong>tly captured. He<br />
was s<strong>en</strong>t<strong>en</strong>ced to a long term of imprisonm<strong>en</strong>t, but<br />
was released wh<strong>en</strong> the British withdrew from the<br />
Transvaal after the first Anglo-Boer War. He was<br />
murdered in 1882 by his half-brother, Mampuru<br />
(who was later executed). Today, built on a boulder<br />
at the foot of the hill where the 1879 action took<br />
place and overlooking the expanse of the Tšate<br />
valley, there is a monum<strong>en</strong>t of Sekhukhune as he<br />
<strong>co</strong>ntemplates the role he has played in the history<br />
of the Pedi.<br />
After the defeat of the Pedi their homeland was<br />
substantially reduced. Reserves—roughly <strong>co</strong>inciding<br />
with the <strong>co</strong>re area of the Pedi heartland—were created<br />
19<br />
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20<br />
tree stories<br />
boomstories<br />
TREE SURVEY IN SEKHUKHUNELAND<br />
for them by the Transvaal Republic’s Native Location<br />
Commission. Over the next hundred years or so, these<br />
reserves were th<strong>en</strong> variously <strong>co</strong>mbined and separated<br />
by a succession of governm<strong>en</strong>t planners. In 1972 the<br />
Northern Sotho homeland of Lebowa was proclaimed<br />
a ‘self-governing’ territory with a population of almost<br />
2 million.<br />
One of the significant European figures in the history<br />
of the Bapedi is Alexander Mer<strong>en</strong>sky, missionary,<br />
sci<strong>en</strong>tist and surgeon. He was attached to the Berlin<br />
Missionary Society and <strong>co</strong>nducted missionary<br />
work among the Bapedi in the Tšate valley from<br />
about 1861 wh<strong>en</strong> Chief Sekhukhune invited him to<br />
build a mission station at Thaba Mosega. By 1865,<br />
however, relationships betwe<strong>en</strong> Sekhukhune and<br />
the Christians deteriorated and Mer<strong>en</strong>sky and his<br />
<strong>co</strong>nverts had to flee the area. They settled near<br />
Middelburg where Botshabelo (city of refuge)<br />
was established. Some other notable missionary<br />
figures who worked in the area include Hermann<br />
Wangemann, and Johannes Winter.<br />
Geology, Minerals, Mining and Mer<strong>en</strong>sky.<br />
The area around the Tšate Heritage site (and indeed<br />
the greater part of Sekhukhuneland) is geologically<br />
a part of the Bushveld Complex, termed one of<br />
the geological wonders of the world. The Bushveld<br />
<strong>co</strong>mplex ext<strong>en</strong>ds from about Rust<strong>en</strong>burg in the<br />
west, eastwards towards Lyd<strong>en</strong>burg, and northwards<br />
towards the Soutpansberg. It was formed about<br />
2000 million years ago through a process whereby<br />
huge masses of molt<strong>en</strong> rock rising from below were<br />
squeezed in betwe<strong>en</strong> layers of sedim<strong>en</strong>tary rock to<br />
form a huge subterranean chamber of rock. These<br />
magmas solidified into differ<strong>en</strong>t layers or reefs of<br />
material. Later a differ<strong>en</strong>t type of magma was intruded<br />
above those formations and crystallised as granite.<br />
The formations that we see at Tšate are the rocks of<br />
the so-called “Rust<strong>en</strong>burg Layered Suite”, the same<br />
formation as found betwe<strong>en</strong> Rust<strong>en</strong>burg and Brits.<br />
The Bushveld <strong>co</strong>mplex <strong>co</strong>ntains large quantities of<br />
relatively rare and e<strong>co</strong>nomically valuable minerals,<br />
such as chromitite, magnetite, and the platinumgroup<br />
minerals. One of the layers of the Bushveld<br />
<strong>co</strong>mplex is called the Mer<strong>en</strong>sky Reef after Hans<br />
Mer<strong>en</strong>sky, notable geologist and son of Alexander<br />
Mer<strong>en</strong>sky, who dis<strong>co</strong>vered the reef that carries his<br />
name in 1924 near Steelpoort.<br />
The mineral wealth of the area may also prove to<br />
be a liability and hast<strong>en</strong> the debasem<strong>en</strong>t of the<br />
e<strong>co</strong>system. There is ext<strong>en</strong>sive mining in the area,<br />
with all the <strong>co</strong>n<strong>co</strong>mitant side-effects such as mining<br />
dumps, air and water pollution, dust, and scarring<br />
of the landscape. Plans are afoot to further ext<strong>en</strong>d<br />
the s<strong>co</strong>pe of mining in order to satisfy the voracious<br />
appetite of industry for minerals and the insatiable<br />
greed of a clan of wealthy individuals. Furthermore<br />
and in order to supply water for mining, industries<br />
and to rural <strong>co</strong>mmunities, the <strong>co</strong>nstruction of the<br />
De Hoop dam on the Steelpoort River has be<strong>en</strong><br />
approved by Cabinet. The l<strong>en</strong>gth of the dam wall<br />
will be about one kilometre, whilst two new bridges<br />
are to be built to reroute sections of the main road<br />
that will be submerged by the rising waters.<br />
Sekhukhuneland C<strong>en</strong>tre of Plant Endemism<br />
(SCPE) The Tšate Heritage Site where we visited<br />
over the week<strong>en</strong>d of 4 to 6 February 2011 lies more<br />
or less in the heart of the Sekhukhuneland C<strong>en</strong>tre<br />
of Plant Endemism (SCPE), so called because of the<br />
high <strong>co</strong>nc<strong>en</strong>tration of plant species within a relatively<br />
small geographic area, in this case Sekhukhuneland.<br />
It is estimated that within the mere 4000 km² area<br />
of the SCPE there are more than 2000 species of<br />
plants, which include about 58 <strong>en</strong>demics, another 70<br />
near-<strong>en</strong>demics, and no less than 46 threat<strong>en</strong>ed plant<br />
species. The topography of the SCPE <strong>co</strong>nsists of rocky<br />
hills, the rugged Leolo Mountains and deep kloofs.<br />
The surface area is <strong>co</strong>vered by basaltic (ultramafic)<br />
rock with high magnesium and iron <strong>co</strong>nt<strong>en</strong>t, such as is<br />
the <strong>co</strong>mposition of the earth mantle.<br />
Near the Tšate Heritage Site lies the expanse of<br />
the Tšate valley with an unrestricted view towards<br />
the north and the silhouette of the Wolkberg in the<br />
distance. The vegetation around the Tšate area is<br />
typically Mountain Bushveld dominated by Kirkia<br />
wilmsii and Acacia caffra.<br />
Tšate Heritage Site Developm<strong>en</strong>t Project<br />
The SCPE is subject to various serious threats:<br />
Growing informal settlem<strong>en</strong>ts and unsustainable landuse<br />
activities (such as un<strong>co</strong>ntrolled wood-harvesting)<br />
have caused land degradation with overgrazing and<br />
soil erosion resulting in under-productive land. In<br />
rec<strong>en</strong>t years these impacts have be<strong>en</strong> exacerbated<br />
by increased population growth and growing resource<br />
demands. Mining activities occupy a large area,<br />
mostly in the valleys, whilst several new prospecting<br />
lic<strong>en</strong>ces have also be<strong>en</strong> granted for the area, including<br />
the Tšate Heritage Site. These impacts are likely to<br />
<strong>co</strong>mpound in the future.<br />
Part of the Tšate valley was proclaimed as a<br />
Provincial Heritage Site in 2007, and, but for the<br />
small Potlake Nature Reserve (of about 30 km²),<br />
this is the only other <strong>co</strong>nservation area within the<br />
bounds of the SCPE. In 2008 the Sekhukhune<br />
TREE SURVEY IN SEKHUKHUNELAND<br />
District Municipality launched the Tšate Heritage<br />
Site Developm<strong>en</strong>t Project which strives to dis<strong>co</strong>ver<br />
and protect the heritage of the Bapedi and the<br />
exceptional biodiversity of the area, whilst also<br />
developing its pot<strong>en</strong>tial as a tourist destination. In<br />
pursuance of this, <strong>co</strong>mmunity members are being<br />
trained as tourist guides, and also assist with<br />
archaeological excavations. An information office<br />
has be<strong>en</strong> established at the Heritage Site.<br />
In an effort to b<strong>en</strong>efit from the tourism pot<strong>en</strong>tial of<br />
the area, primarily by creating jobs for the many<br />
unemployed people, the Sekhukhune District<br />
Municipality has <strong>co</strong>mmissioned a project team for the<br />
developm<strong>en</strong>t of Tšate, whilst Li<strong>za</strong>nne Nel has be<strong>en</strong><br />
appointed as a facilitator of this project. Li<strong>za</strong>nne was<br />
our host for the week<strong>en</strong>d, ably supported by her<br />
husband Gawie. By profession she is a Conservation<br />
Biologist and Tourism Developm<strong>en</strong>t Expert, and works<br />
through her <strong>co</strong>mpany, called 4Life Promotions.<br />
To guide our activities of the week<strong>en</strong>d, and in order<br />
to channel and <strong>co</strong>ntrol our <strong>en</strong>thusiasm, we got the<br />
following brief from Li<strong>za</strong>nne:<br />
“PURPOSE: To get the input of<br />
various experts and specialists on<br />
the biodiversity of the area, as well<br />
as the locality and information on<br />
pot<strong>en</strong>tial tourism attractions and<br />
pot<strong>en</strong>tial routes.”<br />
Tree Spotting around Tšate<br />
The s<strong>co</strong>pe of the survey is broad and it <strong>co</strong>vers differ<strong>en</strong>t<br />
fields of study; h<strong>en</strong>ce, there were delegates from the<br />
Herpetological Society surveying reptiles, from the<br />
Botanical Society assessing flowering plants, there<br />
were Rolf Becker and his team from the Euphorbia<br />
Society, and th<strong>en</strong> there were the repres<strong>en</strong>tatives of the<br />
D<strong>en</strong>drological Society from the branches Pilanesberg,<br />
Magaliesberg, and Waterberg.<br />
The delegates arrived at Tšate valley on the Friday<br />
afternoon, <strong>co</strong>ngregating at the camping site from all<br />
differ<strong>en</strong>t directions. Naas Grové and I shared a car<br />
and we had decided to drive via Middelburg, thus<br />
we approached from the south, travelling along the<br />
<strong>co</strong>urse of the Steelpoort River. It was a pleasant<br />
drive, though marred somewhat by the rel<strong>en</strong>tless<br />
traffic of heavy ore carriers on the road. The last<br />
part of the route where you travel along the valley<br />
of the Steelpoort River is really quite sc<strong>en</strong>ic, and we<br />
<strong>en</strong>joyed the drive. There is already a lot of mining<br />
activity in the valley, and we passed a smelter puffing<br />
tree stories<br />
boomstories<br />
21<br />
DENDRON » No/Nr: 43 » November 2011
DENDRON » No/Nr: 43 » November 2011<br />
22<br />
tree stories<br />
boomstories<br />
TREE SURVEY IN SEKHUKHUNELAND<br />
its waste gasses into an otherwise clear blue sky. A<br />
distance short of Meckl<strong>en</strong>burg (an old missionary<br />
site) we turned off into the Tšate valley, an ext<strong>en</strong>sive<br />
flat at the foot of the <strong>co</strong>mmanding Leolo Mountains.<br />
A string of villages bound the gravel road on either<br />
side with childr<strong>en</strong> and goats equally trying to outrun<br />
the car as we drive along peacefully. Although the<br />
valley has basically be<strong>en</strong> d<strong>en</strong>uded of most trees,<br />
we stopped to photograph some fine specim<strong>en</strong>s of<br />
Bead-bean trees (Maerua angol<strong>en</strong>sis) and Wormbark<br />
false-thorn (Albizia anthelmintica). The Hedge<br />
Euphorbia (Euphorbia tirucalli) is abundant in the<br />
villages and is being ext<strong>en</strong>sively planted to form<br />
imp<strong>en</strong>etrable <strong>en</strong>closures for the paddocks that host<br />
goats and cattle at night.<br />
We stopped at the Information C<strong>en</strong>tre to learn more<br />
about the history and facets of Tšate, and were greeted<br />
by an assembly of fri<strong>en</strong>dly att<strong>en</strong>dants eager to assist<br />
with interesting morsels of information in exchange<br />
for a <strong>co</strong>ld drink. Nearby, there is a warrior-monum<strong>en</strong>t<br />
on an elevated rock <strong>co</strong>mmemorating that fateful day<br />
in 1879 wh<strong>en</strong> the Pedi were defeated at the hands of<br />
British, Boer and Swazi sol<strong>die</strong>rs.<br />
The camping place is on the outskirts, but yet within<br />
the bounds, of the village. It’s laid out on a single<br />
stand and was rather crowded with an exceptionally<br />
large number of visitors and vehicles. We made our<br />
obeisance trying to remember the names of all the new<br />
fri<strong>en</strong>ds we met. We found a most interesting group of<br />
people assembled there on that Friday afternoon: From<br />
the D<strong>en</strong>drological Society there were some real hardwood<br />
heavyweights such as Erwin Grobbelaar, Ni<strong>co</strong><br />
Hager, Naas Grové, and Hans Vahrmeijer. Obviously,<br />
there were also some medium- and light-woods, but<br />
I shall not m<strong>en</strong>tion any names for fear of retribution.<br />
However, the latter two groups did certainly <strong>co</strong>ntribute<br />
ext<strong>en</strong>sively to an <strong>en</strong>tertaining and cheerful ev<strong>en</strong>ing<br />
around a blazing campfire, smothered only by the<br />
ca<strong>co</strong>phonous and disharmonic thump… thump….<br />
thump… emerging from the oversized loudspeakers<br />
of the near-by Shebe<strong>en</strong>, which <strong>co</strong>ntinued until the<br />
early hours of the next day.<br />
The next day was Saturday, and in order to get the<br />
maximum <strong>co</strong>verage we decided to split up into<br />
various groups and <strong>co</strong>mpare notes later. Our fri<strong>en</strong>ds<br />
from the Euphorbia Society w<strong>en</strong>t their way, whilst the<br />
tree people explored the mountain side to the south.<br />
There is a mountain track here, negotiable with your<br />
favourite 4X4. Gawie Oberholzer with only a diff<br />
lock on his bakkie had to give up about half-way up<br />
the slippery slope, but it was good practice for him<br />
anyway! We slowly meandered up the slope, most of<br />
us walking whilst the drivers brought up the vehicles<br />
during id<strong>en</strong>tification-breaks.<br />
The vegetation type we surveyed on this slope and on<br />
the plateau above is classified as Mountain Bushveld<br />
(one of five vegetation types in the SCPE) and we<br />
found an abundance of tree species though the d<strong>en</strong>sity<br />
of these was low to medium. Lower down the slope the<br />
Mauve Chinese-hats (previously Holmskioldia, now<br />
Karomia speciosa) were abundant and in bloom, which<br />
few of us had se<strong>en</strong> before in their natural <strong>en</strong>vironm<strong>en</strong>t.<br />
Patches of the Yellow Bauhinia (Bauhinia tom<strong>en</strong>tosa)<br />
were readily id<strong>en</strong>tifiable by their characteristic<br />
leaf structure and yellow petals. In our group Naas<br />
Grové did most of the id<strong>en</strong>tification work, Johan<br />
Cronje maintained the check list, Gert Middelberg<br />
operated the GPS (for the <strong>co</strong>ordinates and altitude of<br />
our sightings), whilst I did quality <strong>co</strong>ntrol. The latter<br />
is quite an easy job, if you know how. You don’t have<br />
to know too much about trees: All you have to do is<br />
to carry a tree manual, and wh<strong>en</strong>ever Naas says, for<br />
example: “This is a Gro<strong>en</strong>stam bitter-bessie boontjiepeulboom”(i.e<br />
tongue in the cheek for marula), all you<br />
have to ask is: “Why are you saying that?” You’ll be<br />
surprised as to how much you can learn from this!<br />
We <strong>en</strong><strong>co</strong>untered a number of firewood-<strong>co</strong>llecting<br />
gangs making their way up the slope and greeting us<br />
politely. From a distance, and higher up the incline,<br />
you <strong>co</strong>uld soon hear the axes chopping and logs<br />
being manhandled in their efforts to provide <strong>en</strong>ergy<br />
for their ev<strong>en</strong>ing meals. Unfortunately the mountain<br />
side is already virtually stripped of all <strong>co</strong>mbustible<br />
material and it is sorry to observe the last remnants,<br />
which should rather be allowed to decay naturally in<br />
order to support new life and growth, being carried to<br />
the village in the valley below in large bundles.<br />
The Mountain Seringa (Kirkia wilmsii) are very<br />
<strong>co</strong>mmon trees on this west-facing slope. Some are<br />
just barely shrub-like, whilst others grow into tall<br />
trees. Towards the saddle of the mountain we spot an<br />
<strong>en</strong>demic, the Sekhukhune Bushman’s Tea (Lyd<strong>en</strong>burgia<br />
cassinoidesi) and the Bushveld Saffron (Elaeod<strong>en</strong>dron<br />
transvaal<strong>en</strong>sis), both of the latter being members of<br />
the family Celastraceae. There is also a Red-stemmed<br />
Corkwood (Commiphora harveyi) growing happily on<br />
a rock outcrop. As we reach the saddle we take a short<br />
break to view the expanse of the Tšate valley below,<br />
stretching out towards the north-west. We botanise<br />
around the saddle and admire some large specim<strong>en</strong>s<br />
of the Bushveld Kubu-berry (Mystroxylon aethiopicum<br />
subsp. schlechteri) which seem to thrive in this location.<br />
Remarkable also is the abundance of the Monkey’s Tail<br />
(Xerophyta retinervis). The habitat here seems ideal<br />
for these plants, as they grow to a height of more than<br />
two meters, and branch into several stout stems.<br />
From here we drive by car up to a flat and fertile<br />
plateau which is close to the summit of the mountain,<br />
and at an elevation of over 1200 m as against the valley<br />
floor where the elevation is around 850 m. There are<br />
some interesting ruins here, now overgrown d<strong>en</strong>sely<br />
by an assortm<strong>en</strong>t of vegetation. It is said that this was<br />
one of the hideouts of Sekhukhune for those occasions<br />
that he deemed disappearance to be the better part of<br />
valour. On the way towards the plateau we have our<br />
first sightings of the <strong>en</strong>demic Sekhukhune Euphorbia<br />
(Euphorbia sekukuni<strong>en</strong>sis), which occurs only in a very<br />
small area around Sekhukhuneland. On the plateau<br />
there are some fine specim<strong>en</strong>s of the Hairy Rock Fig<br />
(Ficus glumosa), tall trees with an umbrella-like canopy.<br />
TREE SURVEY IN SEKHUKHUNELAND<br />
SEKHUKHUNI-NABOOM, Euphorbia sekukuni<strong>en</strong>sis » Foto: Naas Grové<br />
tree stories<br />
boomstories<br />
While s<strong>co</strong>uting around for trees in the area we kept<br />
an eye op<strong>en</strong> for any possible sightings of avifauna<br />
that should be quite abundant around here. However<br />
it is deplorable to report that we had very few bird<br />
sightings. On the plateau I did observe a Blackcrowned<br />
Tchagra dashing from bush to bush;<br />
overhead some Abdim’s Storks were circling for a<br />
while, and at the campsite there was Yellow-billed<br />
Kite hunting for prey. Similarly, we had only a single<br />
sighting of a mammal, a Rock Dassie which fled<br />
hurriedly as we approached. It appears that the Pedi<br />
have differ<strong>en</strong>t words to describe the various targets of<br />
a hunt: Hunting for birds is performed by young boys<br />
and is called “go tibiša” whilst hunting for game is the<br />
privilege of grown m<strong>en</strong> and is termed “go tsoma”. It<br />
is evid<strong>en</strong>t that both groups are doing a thorough job.<br />
Later in the afternoon we drove by car along the gravel<br />
road leading south, and up a steep pass leading to<br />
the west. The road is fine, and we travelled slowly,<br />
botanising the roadside as we w<strong>en</strong>t. Atop we made a<br />
break to once more <strong>en</strong>joy the vista of the Tšate valley<br />
and the hazy silhouette of a range of hills to the north.<br />
On returning to the campsite we crossed the Motse<br />
River via a low-water bridge. The river was flowing<br />
strongly and cascading downwards over the bridge,<br />
thus creating a waterfall. The temptation was too strong<br />
23<br />
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DENDRON » No/Nr: 43 » November 2011<br />
24<br />
tree stories<br />
boomstories<br />
TREE SURVEY IN SEKHUKHUNELAND<br />
to resist. After the morning’s hike we felt sweaty and<br />
exhausted, and there is a water shortage at the camp,<br />
which rouses guilt wh<strong>en</strong> you climb under the shower.<br />
But the water of the Motse River was actually better: It<br />
looked clean, <strong>co</strong>ol, and inviting. So we stripped and<br />
had a thorough shower provided with the <strong>co</strong>mplim<strong>en</strong>ts<br />
of the Motse River. Whilst chatting and relaxing in the<br />
near-dusk, Johan Cronje sudd<strong>en</strong>ly remembered it was<br />
actually sundowner time and produced a bottle of<br />
fine white wine from the fridge in his car. So we did<br />
some bonding: feet in water, glass in hand. Later, he<br />
remembered that there was actually a bottle of red as<br />
well. Needless to say we returned to camp rather late.<br />
The braai in the ev<strong>en</strong>ing was once again a huge<br />
success: A lively fire, a pot of pap <strong>en</strong> sous, and the<br />
aroma of meat roasting on the fire, whilst we discussed<br />
the successes and disappointm<strong>en</strong>ts of the day.<br />
Betwe<strong>en</strong> the differ<strong>en</strong>t groups we had a list of no less<br />
than 138 differ<strong>en</strong>t species of trees id<strong>en</strong>tified on that<br />
day, and this is only within one of the five vegetation<br />
types found in the SCPE. This is a highly remarkable<br />
achievem<strong>en</strong>t, since a typical week<strong>en</strong>d outing of our<br />
Society will seldom yield a list of more than 60 or so<br />
species. You may imagine the tree <strong>co</strong>unt should we<br />
be able to sp<strong>en</strong>d a few days in the area.<br />
Just to remind us that life is not perfect the local<br />
Shebe<strong>en</strong> started up in the early ev<strong>en</strong>ing, and we were<br />
once again <strong>en</strong>tertained to the intolerable .thump…<br />
thump….thump…until well past midnight.<br />
Other attractions in the area.<br />
The appeal of the Tšate area is certainly not limited<br />
to its rich and varied flora: There are several other<br />
attractions of historic, cultural, and geological interest<br />
in the close proximity, and these are easily accessibly.<br />
Exploring these sights may occupy the better part of<br />
a day and will <strong>en</strong>hance the appreciation of the region.<br />
Among these, the following may be listed:<br />
• Visible surface sections of the Mer<strong>en</strong>sky reef and<br />
the chrome layers of the bushveld <strong>co</strong>mplex;<br />
• The scars of Hans Mer<strong>en</strong>ksy’s first mining<br />
operation;<br />
• Hans Mer<strong>en</strong>sky’s office, which today serves as a<br />
house of prayer;<br />
• Various archaeological sites where artefacts of<br />
the iron age hunter-gatherers have be<strong>en</strong> exposed;<br />
• Rock paintings by the aboriginal people;<br />
• The norite music stones which, wh<strong>en</strong> thumped,<br />
will produce several differ<strong>en</strong>t harmonious notes<br />
from a single stone.<br />
MUSIC STONE » Foto: Naas Grové<br />
Comm<strong>en</strong>ts and Conclusion<br />
What is our evaluation? What about he biodiversity of<br />
the area? What about the tourism pot<strong>en</strong>tial?<br />
Let me emphasize that, with the very limited exposure<br />
we’ve had to the area of Tšate, we can merely voice<br />
some <strong>co</strong>mmon impressions, which may actually be off<br />
the mark wh<strong>en</strong> examined in greater depth.<br />
It is certainly a wise and <strong>en</strong>light<strong>en</strong>ed decision of<br />
the Sekhukhune District Municipality to seek other<br />
sustainable sources of e<strong>co</strong>nomic activity for the area.<br />
Curr<strong>en</strong>tly it appears as though much of the employm<strong>en</strong>t<br />
is dep<strong>en</strong>d<strong>en</strong>t on Mining, but Mining, by its very nature,<br />
is an unsustainable source and all that will remain after<br />
30 or 40 years are a degraded e<strong>co</strong>system and scars in<br />
the landscape. In the mean time, and spurred by the<br />
transi<strong>en</strong>t in<strong>co</strong>me from mining, the local population will<br />
have increased substantially, and the pressures on the<br />
<strong>en</strong>vironm<strong>en</strong>t will have multiplied.<br />
We have found that the area is a tree-lover’s paradise,<br />
but at the same time subject to various serious threats<br />
some of which have be<strong>en</strong> alluded to above.<br />
I believe that, regretfully, the curr<strong>en</strong>t tourism pot<strong>en</strong>tial<br />
of the immediate Tšate area to be rather limited due<br />
to <strong>co</strong>nsiderations such as: Distance from the market<br />
(some 350km from main c<strong>en</strong>tres), proximity of<br />
villages and human habitation, the effects of mining,<br />
degradation of the <strong>en</strong>vironm<strong>en</strong>t, rar<strong>en</strong>ess of avifauna<br />
and mammalians, and (curr<strong>en</strong>tly) inadequate camping<br />
facilities. A real tree-lover will, no doubt, <strong>en</strong>dure and<br />
defy these in<strong>co</strong>nv<strong>en</strong>i<strong>en</strong>ces but, again regretfully, there<br />
are so few of us!<br />
On the other hand: The SCPE is, by all reports, a<br />
rich and diverse area that is demanding very special<br />
and <strong>co</strong>nsiderate preservation against the threats<br />
and pressures facing it. It deserves placing a large<br />
and <strong>co</strong>ntiguous tract of this land under legislated<br />
<strong>co</strong>nservation, preferably in<strong>co</strong>rporating the six<br />
vegetation types id<strong>en</strong>tified by Dr Siebert. Preservation,<br />
rehabilitation and restocking of such land will in time,<br />
Sources:<br />
Publications and Reports:<br />
1. Various Information Brochures kindly supplied by Li<strong>za</strong>nne<br />
Nel<br />
2. HOARE, D. 2007. S<strong>co</strong>ping Report: E<strong>co</strong>logical Study of the<br />
proposed Steelpoort Integration Project.<br />
3. McCARTHY, T. & RUBIDGE, B. 2005. The Story of Earth &<br />
Life, Struik.<br />
4. NORRIS-NEWMAN, C.L. 1976. With the Boers in the<br />
Transvaal. Africana Reprint Library.<br />
5. SIEBERT, S.J. 2001. Vegetation on the ultramafic soils of<br />
TREE SURVEY IN SEKHUKHUNELAND<br />
Some <strong>co</strong>mm<strong>en</strong>ts on Tšate<br />
from a member of the Botanical Society<br />
Sylvie Köhne<br />
no doubt, <strong>en</strong><strong>co</strong>urage tourism and support sustainable<br />
job creation.<br />
But such v<strong>en</strong>tures are exp<strong>en</strong>sive and need to be<br />
financed. The answer, in my mind, is that the Mining<br />
Companies may be approached for funding. After<br />
all, the Mining Companies are reaping where they<br />
did not sow; they are exhausting the valuable assets<br />
of the area and b<strong>en</strong>efiting mostly their investors, the<br />
politicians, and administrators.<br />
It is our sincere hope that the d<strong>en</strong>drological, floral<br />
and other treasures of the SCPE and the Tšate valley<br />
will be preserved and <strong>en</strong>hanced, and that we shall<br />
be able to bring many a more interesting visit to this<br />
fascinating area.<br />
The Limpopo Branch of the Botanical Society joined the D<strong>en</strong>drological Society at Tsate, and <strong>en</strong>joyed<br />
meeting lots of differ<strong>en</strong>t people. The plant life impressed the <strong>en</strong>tire party and there was something for<br />
everyone: special trees for the d<strong>en</strong>drologically inclined, beautiful forbs with huge ornam<strong>en</strong>tal pot<strong>en</strong>tial<br />
for the tissue culture expert, some spiny Euphorbias for the succul<strong>en</strong>t <strong>en</strong>thusiasts, and grasslands<br />
exploding with flowers of every kind after the good rains. As summit grasslands support high plant<br />
diversity and numbers of <strong>en</strong>demic plants, the BotSoc group focussed on the grasslands around the Tama<br />
Kgoshi peak of the Leolo Mountains on Saturday. Tw<strong>en</strong>ty-one herbaceous flowering plant species were<br />
re<strong>co</strong>rded, including the d<strong>en</strong>sely flowered orange Gladiolus crassifolius, the perfectly camouflaged gre<strong>en</strong><br />
Hab<strong>en</strong>aria orchid species as well as the beautiful red Streptocarpus dunnii. Apart from their <strong>co</strong>nservation<br />
value, many of the grassland plants have medicinal, cultural and nutritional value for the local rural<br />
<strong>co</strong>mmunities. A herdsman offering Zantedeschia tubers for sale was <strong>en</strong><strong>co</strong>untered, and erosion caused<br />
by overgrazing was noticed. Irreversible transformation of grasslands needs to be <strong>co</strong>ntrolled as the<br />
most critical e<strong>co</strong>system function that pristine grasslands fulfil is that of water catchm<strong>en</strong>t. In a waterstressed<br />
<strong>co</strong>untry such as South Africa, their role as <strong>co</strong>llectors of rainwater and their ability to hold water<br />
underground, or in form of wetlands, and th<strong>en</strong> slowly release it throughout the year is crucial.<br />
the Sekhukhuneland C<strong>en</strong>tre of Endemism.Ph.D. thesis,<br />
University of Pretoria, Pretoria.<br />
Internet Resources:<br />
1. www.krugerpark.<strong>co</strong>.<strong>za</strong>/africa_pedi.html<br />
2. www.<strong>en</strong>cyclopedia.<strong>co</strong>m/<br />
3. <strong>en</strong>.wikipedia.org/wiki/Pedi_people<br />
4. www.e<strong>za</strong>kwantu.<strong>co</strong>m<br />
5. www.dwa.gov.<strong>za</strong>/ORWRDP/Dehoop/index.asp<br />
6. www.sekhukhune.gov.<strong>za</strong>/<br />
7. www.sahistory.org.<strong>za</strong>/, South African History online<br />
tree stories<br />
boomstories<br />
25<br />
DENDRON » No/Nr: 43 » November 2011
DENDRON » No/Nr: 43 » November 2011<br />
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DIE MAROELABOS VAN TSHIPISE-”DUIN” » Berig op volg<strong>en</strong>de bladsy<br />
27<br />
DENDRON » No/Nr: 43 » November 2011
DENDRON » No/Nr: 43 » November 2011<br />
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tree stories<br />
boomstories<br />
DIE MAROELABOS VAN TSHIPISE-”DUIN”<br />
Die Maroelabos <strong>van</strong> Tshipise-”duin”<br />
Die fyn, los, rooi sand waaruit <strong>die</strong> duinagtige<br />
heuwel aan <strong>die</strong> suidoostekant <strong>van</strong> Tshipisekoppie<br />
(Limpopo) bestaan is afkomstig <strong>van</strong> ‘n plaaslike<br />
sandste<strong>en</strong>formasie: “Dominantly red lithologies<br />
characterise the Bosbokpoort Formation (Karoo<br />
Group) which reaches a maximum thickness of<br />
100 m in the Tshipise area. The lower part <strong>co</strong>nsists<br />
of massive mudstone followed by siltstone which<br />
occasionally grades into very fine sandstone.” (Brandl,<br />
1981). Volg<strong>en</strong>s mnr. N. Baglow <strong>van</strong> <strong>die</strong> Raad vir<br />
Geowet<strong>en</strong>skap het <strong>die</strong> heuwel in situ deur verwering<br />
<strong>van</strong> ‘n deel <strong>van</strong> hier<strong>die</strong> formasie ontstaan (pers. med.).<br />
Die rooi sand vorm ‘n dramatiese, skerp kontaklyn met<br />
<strong>die</strong> grys sandste<strong>en</strong>koppie, wat daarop dui dat dit e<strong>en</strong>s<br />
onderhewig was aan verskuiwing. Die hele omgewing<br />
is deurkruis <strong>van</strong> verskuiwingslyne.<br />
Anders as wat ‘n m<strong>en</strong>s sou verwag, is <strong>die</strong> maroela<br />
(Sclerocarya birrea subsp. caffra) <strong>die</strong> dominante boom<br />
op <strong>die</strong> heuwel. Soos uit Fig. 1 blyk, staan <strong>die</strong> maroelas<br />
in digte, amper woudagtige, afsonderlike groepe op<br />
<strong>die</strong> sand. Geassosieerde spesies is: Commiphoraspp.,<br />
haak-<strong>en</strong>-steek (Acacia tortilis subsp.<br />
heteracantha), fynblaarrooihout (Ochna serrulata),<br />
sesambos (Sesamothamnus lugardii), helikopterspaanvrug<br />
(Hippocratea longipetiolata), witrosyntjie<br />
(Grewia bi<strong>co</strong>lor) <strong>en</strong> kremetart (Adansonia digitata).<br />
(Die vaal bossies in <strong>die</strong> oop dele tuss<strong>en</strong> <strong>die</strong> bome is<br />
<strong>die</strong> “doringblaarbossie” (Blepharis subvolubilis) met<br />
hul pragtige blou tot ligpers blomlippe).<br />
Die grootste maroelas staan te<strong>en</strong> <strong>die</strong> voet <strong>van</strong> <strong>die</strong><br />
heuwel (Figure 2 <strong>en</strong> 3). Hoër op word <strong>die</strong> bome al<br />
hoe kleiner <strong>en</strong> armoediger (Figure 4 <strong>en</strong> 5), tot waar<br />
sommige met hul dun, krom geboë stammetjies<br />
nouliks meer beelddraers <strong>van</strong> <strong>die</strong> trotse maroelaspesie<br />
g<strong>en</strong>oem kan word (Fig. 6). In <strong>die</strong> winter verloor <strong>die</strong><br />
kruinbome ook hul blare ietwat voor <strong>die</strong> onderstes.<br />
(Die foto’s is almal op 22 Junie 2011 g<strong>en</strong>eem). Die rede<br />
vir hul opsigtelike agterstand is waarskynlik <strong>die</strong> sand<br />
se onvermoë om reënwater vir lang g<strong>en</strong>oeg tydperke,<br />
na behoefte <strong>van</strong> <strong>die</strong> bome, te behou. Die kruinbome<br />
ly gevolglik makliker watergebrek as <strong>die</strong> basisbome.<br />
Die maroela is ‘n bosveldboom wat op meerdere<br />
grondtipes voorkom, bv. op sand, leemgrond <strong>en</strong><br />
selfs klipperige grond (maar nie op turf nie). Sy<br />
eerste liefde is egter sand- of sandleemgronde (De<br />
Winter e.a., 1966). In der waarheid staan <strong>die</strong> grootste<br />
amptelik gemete maroela in Suid-Afrika op e<strong>en</strong> <strong>van</strong><br />
<strong>die</strong> Springbokvlakte se sandbulte (D<strong>en</strong>dron 39:14-<br />
Ni<strong>co</strong> Hager<br />
15). Dat maroelabome op ‘n sand-“duin” kan groei, is<br />
daarom nie so ongewoon as wat ‘n m<strong>en</strong>s g<strong>en</strong>eig is om<br />
te dink nie; <strong>die</strong> “duin” is immers sand <strong>en</strong> nie juis baie<br />
hoog nie (30 m). Wat wel uitsonderlik is, is <strong>die</strong> bome<br />
se verspreidingswyse in bykans homog<strong>en</strong>e groepe,<br />
te<strong>en</strong>strydig met hul aard (Grant & Thomas, 2002)<br />
(Figure 2-11). Waar <strong>die</strong> m<strong>en</strong>s nie ingem<strong>en</strong>g het nie,<br />
kom <strong>die</strong> maroela gewoonlik slegs yl verspreid tuss<strong>en</strong><br />
dominante bome waarmee dit assosieer voor, bv.<br />
knoppiesdoring (Acacia nigresc<strong>en</strong>s) <strong>en</strong> wilde sering<br />
(Burkea africana). Sy forse gestalte t<strong>en</strong> spyt, vind ‘n<br />
m<strong>en</strong>s hom selde in <strong>die</strong> rol <strong>van</strong> heerser. Vanwaar dan<br />
sy onbetwiste gesag oor hier<strong>die</strong> sandheuwel?<br />
Fotos:<br />
Ni<strong>co</strong> Hager<br />
Erk<strong>en</strong>nings:<br />
Dank is verskuldig aan mnr. Johan Blignaut <strong>van</strong> Forever Resorts,<br />
Tshipise vir <strong>die</strong> gebruik <strong>van</strong> hul fasiliteite, aan mnr. Nick Baglow<br />
<strong>van</strong> <strong>die</strong> Raad vir Geowet<strong>en</strong>skap vir inligting <strong>en</strong> aan prof. Braam<br />
<strong>van</strong> Wyk <strong>van</strong> <strong>die</strong> Universiteit <strong>van</strong> Pretoria vir sy opbou<strong>en</strong>de<br />
komm<strong>en</strong>taar op <strong>die</strong> manuskrip.<br />
Bronnelys:<br />
BRANDL, G. 1981. The geology of the Messina area. Geological<br />
Survey. Governm<strong>en</strong>t Printer, Pretoria.<br />
DE WINTER, B., DE WINTER, M. & KILLICK, D.J.B. 1966. Ses-<strong>en</strong>sestig<br />
Transvaalse bome. Navorsingsinstituut vir Plantkunde.<br />
Voortrekkerpers Beperk, Johannesburg.<br />
GRANT, R. & THOMAS, V. 2002. Sappi tree spotting in Bushveld.<br />
Jacana Education, Johannesburg.<br />
Figure 1-12 is foto’s <strong>van</strong> <strong>die</strong> digte stande maroela (Sclerocarya<br />
birrea subsp. caffra) wat op <strong>die</strong> rooi sandheuwel aan <strong>die</strong><br />
suidoostekant <strong>van</strong> Tshipisekoppie (Limpopo) staan.<br />
Fig. 1: Gedeelte <strong>van</strong> <strong>die</strong> Tshipise-“duin”. Die heuwel is 1.03<br />
km lank, 350 m breed <strong>en</strong> 30 m hoog. Die digte gro<strong>en</strong> kolle is<br />
maroelabome. Die dramatiese kontak <strong>van</strong> <strong>die</strong> rooi sand met <strong>die</strong><br />
grys sandste<strong>en</strong> dui ‘n verskuiwingslyn aan.<br />
Fig. 2: Basisbome<br />
Fig. 3: Basisbome<br />
Fig. 4: Hoërligg<strong>en</strong>de bome<br />
Fig. 5: Hoërligg<strong>en</strong>de bome<br />
Fig. 6: Armoedige kruinbome<br />
Figure 7-11: Groepe maroelabome<br />
Fig. 12: Sandheuwel <strong>en</strong> sandste<strong>en</strong>koppie word deur ‘n steil klofie<br />
geskei. (Nie sigbaar op <strong>die</strong> satellietfoto nie). Soutpansberg in <strong>die</strong><br />
agtergrond. Rigting: suidwes.<br />
FIG 1<br />
FIG 4<br />
FIG 7<br />
FIG 10<br />
FIG 2<br />
FIG 5<br />
FIG 8<br />
FIG 11<br />
29<br />
FIG 3<br />
FIG 6<br />
FIG 9<br />
DENDRON » No/Nr: 43 » November 2011<br />
FIG 12
DENDRON » No/Nr: 43 » November 2011<br />
30<br />
tree stories<br />
boomstories<br />
PALMBOME<br />
Palmbome: Koninklike plante<br />
Die belangstelling in palmbome gr<strong>en</strong>s soms<br />
na aan dweepsug. Daar is waarskynlik nie<br />
’n tuin in Suid-Afrika sonder ’n palmboom nie –<br />
hoe groot of klein ookal <strong>die</strong> erf. Palmbome word<br />
getakseer vir hul ornamtele asook kommersiële<br />
waarde <strong>van</strong> sommige spesies.<br />
Palms is houtagtige e<strong>en</strong>saadlobbige blomplante<br />
wat aan <strong>die</strong> Arecaceae-familie (alternatiewelik<br />
<strong>die</strong> Palmae) behoort. Die plante het almal ’n baie<br />
k<strong>en</strong>merk<strong>en</strong>de groeivorm wat dit selfs vir ’n leek<br />
maklik maak om te onderskei <strong>van</strong> ander plante.<br />
Alhoewel hul nie verwant is aan <strong>die</strong> broodbome<br />
(Zamiaceae-familie), <strong>die</strong> boomvarings<br />
(Cyathaeceae-familie), Pandanaceae-familie,<br />
kiepersole (Araliaceae-familie) <strong>en</strong> vlasplante<br />
(Cordyline-familie) nie, kan hulle maklik met<br />
mekaar verwar word.<br />
Antieke lew<strong>en</strong>svorm<br />
Palms is antieke lew<strong>en</strong>svorme <strong>en</strong> fossiel rekords<br />
toon aan dat dit dateer uit <strong>die</strong> laat Kryt-tydperk<br />
(circa 145.5 tot 65.5 miljo<strong>en</strong> jaar gelede) wat <strong>die</strong><br />
einde <strong>van</strong> <strong>die</strong> groot uitwissing <strong>en</strong> onder andere<br />
<strong>die</strong> dinosaurusse aangekondig het. Omdat <strong>die</strong><br />
plante houtagtig is, is goeie fossielrekords gevind<br />
<strong>en</strong> is dit nie onmoontlik dat dié plante selfs<br />
nog vóór <strong>die</strong> Kryt-tydperk kon geleef het nie.<br />
Ekologiese veranderings het sedert daar<strong>die</strong> tyd<br />
wel plaasgevind <strong>en</strong> si<strong>en</strong> ons <strong>van</strong>dag dat spesies<br />
in ander habitatte oorleef as waar <strong>die</strong> oorblyfsels<br />
<strong>van</strong> fossiele oorspronklik gevind is. Stuifmeel <strong>van</strong><br />
byvoorbeeld <strong>die</strong> Nypa fruticans (moeraspalm) wat<br />
<strong>van</strong>dag net in <strong>die</strong> trope voorkom is in sedim<strong>en</strong>te<br />
naby London ontdek.<br />
Aantal spesies<br />
Dit is ’n uiters ingewikkelde groep plante met<br />
verskeie variëteite rondom ‘n basiese tema. Die<br />
Sweedse plantkundige Carl von Linne (Linnaeus)<br />
het <strong>die</strong> plante as <strong>die</strong> prins <strong>van</strong> plante gedoop.<br />
Daar word tuss<strong>en</strong> 210 – 236 palmfamilies <strong>en</strong> tuss<strong>en</strong><br />
2 500 <strong>en</strong> 3 500 palmspesies in <strong>die</strong> wêreld erk<strong>en</strong>.<br />
Die verskil in <strong>die</strong> aantal families <strong>en</strong> spesies is te<br />
wyte aan plantkundiges wat nie kan saamstem oor<br />
<strong>die</strong> afbak<strong>en</strong>ing <strong>van</strong> families <strong>en</strong> <strong>van</strong> <strong>die</strong> spesies<br />
nie. Palmbome is <strong>die</strong> vierde grootste groep<br />
e<strong>en</strong>saadlobbige plante <strong>en</strong> daar word nog jaarliks<br />
nuwe spesies ontdek. In Suid-Afrika is daar slegs<br />
ses inheemse plamspesies, naamlik Pho<strong>en</strong>ix<br />
reclinata (wilde-dadelplam), Hypha<strong>en</strong>e petersiana<br />
(Noordele-lalapalm), H. <strong>co</strong>riacea (lalaplam),<br />
Naas Grové<br />
Borassus aethiopum (Afrika-waaierpalm), Raphia<br />
australis (Kosi-palm) <strong>en</strong> Jubaeopsis caffra (Pondpalm).<br />
Die plante word selde in tuine aangetref met<br />
met <strong>die</strong> uitsondering <strong>van</strong> <strong>die</strong> wilde-dadelpalm, wat<br />
kommersieël redelik besikbaar is.<br />
Algem<strong>en</strong>e groei k<strong>en</strong>merke<br />
Palms is meerjarige, <strong>en</strong>kel- of tweeslagtige plante<br />
met k<strong>en</strong>merk<strong>en</strong>de kroonblare. Dit plant deur middel<br />
<strong>van</strong> saad voort. Meeste plante het ’n k<strong>en</strong>merk<strong>en</strong>de<br />
bogrondse stam, met uitsondering <strong>van</strong> ’n paar<br />
spesies wat ’n ondergrondse stam het. Alhoewel <strong>die</strong><br />
meeste palms ’n <strong>en</strong>kelvoudige stam het, is daar ’n<br />
hele aantal wat k<strong>en</strong>merk<strong>en</strong>d meerstammig <strong>van</strong>af<br />
<strong>die</strong> basis <strong>van</strong> <strong>die</strong> plant vertak. Die groeivorm staan<br />
bek<strong>en</strong>d as verklompte of saamgedronge stamme. By<br />
<strong>die</strong> Licuala, Hypha<strong>en</strong>e, Ptychosperma, Gronophyllum<br />
<strong>en</strong> Pinaga-spesies kom <strong>en</strong>kelstammige sowel as<br />
verklompte groeivorms voor. Die blare <strong>van</strong> palms<br />
is baie opvall<strong>en</strong>d <strong>en</strong> het ’n baie k<strong>en</strong>merk<strong>en</strong>de<br />
voorkoms. Blare is bykans sonder uitsondering<br />
altyd aan <strong>die</strong> bopunt <strong>van</strong> <strong>die</strong> stam saamgedronge.<br />
Meeste spesies se blare is handvormig of<br />
veervormig saamgestel, maar e<strong>en</strong> groep, Caryota,<br />
het dubbelveervormig saamgestelde blare.<br />
Slegs volwasse plante blom <strong>en</strong> by sommige spesies<br />
kan dit op drie-jarige ouderdom plaasvind, terwyl<br />
ander weer veertig jaar neem voordat dit wasdom<br />
bereik. Sodra dit wasdom bereik het blom <strong>die</strong> meeste<br />
plante jaarliks. Monokarpiese plante, waaronder <strong>die</strong><br />
inheemse Raphia australis (wilde-dadelplam), blom<br />
slegs e<strong>en</strong> keer in sy leeftyd waarna <strong>die</strong> plant vrek.<br />
Meeste blomme is oninterresant, soms welriek<strong>en</strong>d<br />
<strong>en</strong> word deur insekte <strong>en</strong> deur <strong>die</strong> wind bestuif. E<strong>en</strong>of<br />
tweeslagtige blomme kom op afsonderlike plante<br />
voor <strong>en</strong> by sommige spesies beide geslagte op<br />
<strong>die</strong>selfde plant in <strong>die</strong>selfde blom.<br />
Die vrugte is meestal klein <strong>en</strong> word in oorvloed gedra.<br />
Die uitsondering is <strong>die</strong> kokosneut wat <strong>en</strong>kele groot<br />
vrugte dra. Daar kom gewoonlik e<strong>en</strong> tot drie, selde<br />
meer as drie sade, in ‘n elke vrug voor.<br />
Palms in <strong>die</strong> wêreld<br />
Palms kom wyd verspreid regoor <strong>die</strong> wêreld, veral<br />
in <strong>die</strong> tropiese dele, voor. Dit sal selde in baie droë<br />
streke aangetref word. Die mees noordelike palm<br />
Chamaerops excelsa kom bokant <strong>die</strong> 44˚N voor. ‘n<br />
Variëteit <strong>van</strong> Rhopalostylis sapida is <strong>die</strong> palm wat<br />
<strong>die</strong> verste suid op <strong>die</strong> Catham eiland, oos <strong>van</strong> Nieu-<br />
Zeeland (44˚18’S) voorkom.<br />
NOORDELE-LALAPALM Hypha<strong>en</strong>e petersiana » Foto: Naas Grové<br />
Palms kan op verskill<strong>en</strong>de hoogtes bo seespieël<br />
aangetref word. Die Ceroxylon utile is <strong>die</strong> spesie<br />
wat <strong>die</strong> hoogste bo seespieël in <strong>die</strong> Andes<br />
gebergtes op ’n hoogte <strong>van</strong> 4 000m groei. Talle<br />
spesies word by seevlak aangetref, maar ook<br />
in woude waar <strong>die</strong> hoogte bo seespieël wissel<br />
tuss<strong>en</strong> 2 000 – 2 400m.<br />
T<strong>en</strong> spyte <strong>van</strong> <strong>die</strong> groot verspreiding <strong>en</strong> digtheid<br />
<strong>van</strong> plams in <strong>die</strong> trope, is daar baie min families<br />
wat wyd verspreid oor ’n groot area voorkom. Dit<br />
is dus nie vreemd dat baie <strong>van</strong> <strong>die</strong> palm-families<br />
<strong>en</strong>demies tot ’n streek is nie. Die vermoede is dat<br />
palms oor <strong>die</strong> vermoë beskik om te evoleer <strong>en</strong><br />
sodo<strong>en</strong>de by ‘n spesifike nis in <strong>die</strong> omgewing met<br />
min moeite kan aanpas. So is daar byvoorbeeld<br />
vier spesies palms wat aan drie families behoort<br />
wat <strong>en</strong>demies is aan <strong>die</strong> Lord Howe Eiland in<br />
<strong>die</strong> See <strong>van</strong> Tasmanië, ongeveer 600km oos <strong>van</strong><br />
<strong>die</strong> vasteland <strong>van</strong> Australië. In Fidji kom daar 22<br />
palmspesies wat aan 10 g<strong>en</strong>era behoort voor.<br />
Bykans al dié spesies is <strong>en</strong>demies tot Fidji <strong>en</strong> vyf<br />
<strong>van</strong> <strong>die</strong> families word net daar aangetref.<br />
Palm habitat<br />
Daar word berek<strong>en</strong> dat ongeveer twee derdes<br />
<strong>van</strong> <strong>die</strong> palms <strong>van</strong> <strong>die</strong> wêreld in <strong>die</strong> reënwoude<br />
voorkom. ’n Beduid<strong>en</strong>de hoeveelheid kom egter<br />
PALMBOME<br />
ook voor in sa<strong>van</strong>na grasveld <strong>en</strong> yl bebosde streke.<br />
Meeste <strong>van</strong> laasg<strong>en</strong>oemde is geharde spesies wat<br />
aangepas is by <strong>die</strong> droër omstandighede <strong>en</strong> kan dus<br />
veldbrande oorleef. ’n K<strong>en</strong>merk <strong>van</strong> dié tipe palms<br />
is dat waar hulle voorkom dit dikwels digte stande<br />
vorm (Borassus, Livistona, Pho<strong>en</strong>ix, Hypha<strong>en</strong>e <strong>en</strong><br />
Raphia). ’n Paar spesies het by spesifieke habitatte<br />
<strong>en</strong> grondtipes aangepas waar hulle suksesvol met<br />
ander plante om oorlewing kan meeding. Dit sluit<br />
in gevalle waar dit langs kuslyne, vloedvlaktes,<br />
moerasse, vleie <strong>en</strong> selfs in waterstrome kan oorleef.<br />
Slegs e<strong>en</strong> spesie, naamlik <strong>die</strong> moeraspalm (Nypa<br />
fruticans) wat in Asië aangetref word groei in <strong>die</strong><br />
sagte modder <strong>van</strong> riviermondings. Die Rav<strong>en</strong>ea<br />
musicalis <strong>van</strong> Madagaskar oorleef in vinnig<br />
vloei<strong>en</strong>de water <strong>van</strong> tot 2.5m <strong>die</strong>p. Enkele spesies<br />
kan sneeu deurstaan soos Narrorrhops ritchiana in<br />
<strong>die</strong> Afgaanse gebergtes <strong>en</strong> ’n spesie <strong>van</strong> <strong>die</strong> g<strong>en</strong>us<br />
Trachycarpus (windmeulpalms) wat in <strong>die</strong> Himalajas<br />
aangetref word.<br />
Baie min palms kan droogte weerstaan maar<br />
<strong>en</strong>keles kon aanpas, wat hulle toelaat om in<br />
baie droë omstandighede te oorleef. Die plante<br />
word egter meestal naby of langs perman<strong>en</strong>te<br />
waterbronne aangetref, of waar <strong>die</strong> watertafel baie<br />
na aan <strong>die</strong> oppervlakte is. Die bek<strong>en</strong>dste hier<strong>van</strong><br />
tree stories<br />
boomstories<br />
31<br />
DENDRON » No/Nr: 43 » November 2011
DENDRON » No/Nr: 43 » November 2011<br />
32<br />
tree stories<br />
boomstories<br />
PALMBOME<br />
is sekerlik <strong>die</strong> oase dadelpalm (Pho<strong>en</strong>ix dactylifera)<br />
wat kommersieël in verskeie dele <strong>van</strong> <strong>die</strong> wêreld vir<br />
dadels gekweek word, ook hier in Suid-Afrika.<br />
Ei<strong>en</strong>aardighede <strong>van</strong> palms<br />
Ei<strong>en</strong>aardighede <strong>en</strong> talle interessanthede word<br />
onder <strong>die</strong> groep plante aangetref. Dit<br />
is nie algeme<strong>en</strong> bek<strong>en</strong>d nie dat <strong>die</strong><br />
grootste saad, <strong>die</strong> langste blaar <strong>en</strong><br />
<strong>die</strong> grootste blom by palms aangetref<br />
word. Die Lodoicea maldivaca (Dubbel<br />
Kokosneutpalm) <strong>van</strong> <strong>die</strong> Seychelles<br />
produseer reusagtige vrugte <strong>en</strong> e<strong>en</strong><br />
<strong>en</strong>kele saad <strong>van</strong> <strong>die</strong> palm kan tot 20kg<br />
weeg. Die langste blaar kom voor by <strong>die</strong> S<strong>en</strong>traal<br />
Afrika rafia-palm (Raphis regalis). ’n Rekord l<strong>en</strong>gte<br />
<strong>van</strong> 25.11m is aangetek<strong>en</strong>. Talle ander spesies <strong>van</strong><br />
<strong>die</strong> Raphia-g<strong>en</strong>us het blare wat langer as 20m is.<br />
Die reusagtige indrukwekk<strong>en</strong>de kandelaaragtige<br />
bloeiwyse <strong>van</strong> <strong>die</strong> Corypha umbraculifera (Talipotpalm)<br />
wat in Indië aangetref word, kan tot ti<strong>en</strong><br />
miljo<strong>en</strong> blomme per bloeiwyse op e<strong>en</strong> slag<br />
produseer! Uiterstes in <strong>die</strong> l<strong>en</strong>gte onder <strong>die</strong> palms<br />
kom ook voor, as ’n m<strong>en</strong>s <strong>die</strong> kleinste palm met <strong>die</strong><br />
hoogste e<strong>en</strong> vergelyk. Die dwergplam (Syagrus<br />
lilliputiana) wat in Paraguay voorkom is skaars 15cm<br />
hoog as dit volgroei is. Op <strong>die</strong> ander uiterste is <strong>die</strong><br />
Wasplams (Ceroxylon Quindiu<strong>en</strong>se <strong>en</strong> C. alpinum)<br />
<strong>van</strong> <strong>die</strong> Andes-gebergtes wat tot 60m hoog kan<br />
word.<br />
Bewaring <strong>van</strong> palms<br />
Soos met <strong>die</strong> meeste plant- <strong>en</strong> <strong>die</strong>rspesies het<br />
palms ook nie <strong>die</strong> vernietigingsdrang <strong>van</strong> <strong>die</strong><br />
m<strong>en</strong>s vrygespring nie. Habitatvernietiging is<br />
waarskynlik <strong>die</strong> e<strong>en</strong> <strong>en</strong>kele grootste oorsaak wat <strong>die</strong><br />
voorbestaan <strong>van</strong> <strong>die</strong> oer-oue spesies bedreig. Dit is<br />
veral grootskaalse ontbosting, mynbou-aktiwiteite,<br />
self bestaan boerdery, degradasie <strong>van</strong> <strong>die</strong> grond <strong>en</strong><br />
erosie wat <strong>die</strong> groot sondebokke is. Ongelukkig is<br />
dit nie <strong>die</strong> <strong>en</strong>igste bedreiging nie. Talle dele <strong>van</strong><br />
<strong>die</strong> plant word tradisioneel vir ’n verskeid<strong>en</strong>heid<br />
gebruike aangew<strong>en</strong>d. Die blare <strong>van</strong> Vetchia<br />
montgomeryana <strong>en</strong> Pritchhardiopsis jeann<strong>en</strong>eyi<br />
se status in <strong>die</strong> natuur is uiters skaars omdat <strong>die</strong><br />
blare vir ’n delikatesse in restourante aangebied<br />
word. Die gebruik <strong>van</strong> <strong>die</strong> blare <strong>van</strong> <strong>die</strong> Kosipalm<br />
vir weefwerk <strong>en</strong> vee voer, hou ’n soortgelyke<br />
bedreiging in. In <strong>die</strong> noorde <strong>van</strong> Botswana <strong>en</strong><br />
Namibië word reuse bome Hypha<strong>en</strong>e petersiana<br />
Ongeveer<br />
nege<br />
palmspesies<br />
het al<br />
uitgesterf.<br />
(Noordele-lalapalm) jaarliks vir hul sap getap wat<br />
as basis vir <strong>die</strong> brou <strong>van</strong> ’n lokale bier di<strong>en</strong>. Na drie<br />
of vier jaar vrek <strong>die</strong> bome <strong>en</strong> is <strong>die</strong> uitgedroogte<br />
stamme <strong>die</strong> <strong>en</strong>igste tek<strong>en</strong>s wat oorgebly het <strong>van</strong> ’n<br />
e<strong>en</strong>s swierige plant.<br />
Onoordeelkundige versameling <strong>van</strong><br />
saad deur versamelaars voeg nie veel<br />
waarde toe nie. In <strong>die</strong> meeste gevalle<br />
sal <strong>die</strong> saad nie ontkiem t<strong>en</strong>sy <strong>die</strong><br />
medium waarin dit geplant word, <strong>die</strong><br />
natuurlike habitat kunsmatig naboots<br />
nie.<br />
Ongeveer nege palmspesies het al uitgesterf,<br />
meestal as gevolg <strong>van</strong> m<strong>en</strong>slike inm<strong>en</strong>ging. Die<br />
jongste toevoeging tot <strong>die</strong> lys was in 1985 toe <strong>die</strong><br />
Sabal miami<strong>en</strong>sis op <strong>die</strong> lys geplaas is as gevolg<br />
<strong>van</strong> stedelike uitbreiding in <strong>die</strong> Amerikaanse staat<br />
Florida. In Kuba het <strong>die</strong> Roystonea stellata uitgesterf<br />
omdat <strong>die</strong> natuurlike habitat deur m<strong>en</strong>se versteur is.<br />
Die interessante Oase-palm <strong>van</strong> Egipte (Medemia<br />
argun) is sedert 1964 nog nie weer in <strong>die</strong> natuur<br />
opgemerk nie, <strong>en</strong> daar word vermoed dat dit ook<br />
uitgesterf het.<br />
Palms se ekonomiese waarde word na grasse hoog<br />
aangeskryf. Talle geme<strong>en</strong>skappe in <strong>die</strong> tropiese <strong>en</strong><br />
sub-tropiese dele <strong>van</strong> <strong>die</strong> wêreld se voortbestaan<br />
is direk gekoppel aan <strong>die</strong> voorkoms <strong>van</strong> <strong>die</strong> plante.<br />
Dit is wonderlike plante. Nie net vir hul skoonheid<br />
<strong>en</strong> ornam<strong>en</strong>tele prag wat dit aan ’n tuin verle<strong>en</strong> nie,<br />
maar ook as potplante <strong>en</strong> kantoorversierings.<br />
Bronnelys:<br />
Johnston D. 1987. Conservation status of Wild Palms in Latin<br />
America and the Carribean, Princeps 31 pp 96 – 97<br />
Jones, DL. 1995. Palms throughout the World. Reed Books Australia<br />
Langlois, AC. 1976. Supplem<strong>en</strong>t to Palms of the World. University<br />
Press, Florida<br />
Moore, HE (Jr). 1978. Endangerm<strong>en</strong>t of the specific and g<strong>en</strong>eric<br />
levels in Palms. Princeps 23, pp 47 – 64<br />
Tomlinson, PB. 1990. The structural biology of Palms. Clar<strong>en</strong>don<br />
Press, Oxford<br />
Internet<br />
http://<strong>en</strong>.wikipedia.org/wiki/Arecaceae<br />
http://www.2020site.org/trees/palm-tree.html<br />
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33<br />
DENDRON » No/Nr: 43 » November 2011
DENDRON » No/Nr: 43 » November 2011<br />
34<br />
review<br />
review<br />
Mynbou in Limpopo provinsie<br />
Die D<strong>en</strong>drologiese Ver<strong>en</strong>iging se rol<br />
Verskeie mynbou <strong>en</strong> prospekteringsprojekte<br />
in <strong>die</strong> Limpopo <strong>en</strong> Mpumalanga provinsies<br />
het <strong>die</strong> afgelope twee jaar groot media-dekking<br />
<strong>en</strong> protes <strong>van</strong> nie-regeringsorganisasies (NROs)<br />
ontlok. Die mees bek<strong>en</strong>de is <strong>die</strong> Vele-myn langs <strong>die</strong><br />
Limpoporivier <strong>en</strong> Mapungubwe Nasionale Park in<br />
<strong>die</strong> noorde <strong>van</strong> <strong>die</strong> Limpopo provinsie. Onlangs het<br />
prospektering deur <strong>die</strong>selfde mynboumaatskappy<br />
(Coal Africa) aan <strong>die</strong> noordelike hang <strong>van</strong> <strong>die</strong><br />
Soutpansberg ook voorbladnuus gehaal we<strong>en</strong>s <strong>die</strong><br />
impak op beskermde plant- <strong>en</strong> <strong>die</strong>relewe.<br />
Velemyn het twee omgewingsimpakprosedures<br />
ondergaan, waaraan vele NROs, insluit<strong>en</strong>d <strong>die</strong><br />
D<strong>en</strong>drologiese Ver<strong>en</strong>iging deelg<strong>en</strong>eem het. Die<br />
eerste omgewingsimpakstu<strong>die</strong> het oopgroef <strong>en</strong><br />
ondergrondse ste<strong>en</strong>koolontginning oor ‘n area <strong>van</strong><br />
8663 hektaar behels. Die Ver<strong>en</strong>iging se belang<br />
was eerst<strong>en</strong>s by <strong>die</strong> grootskaalse vernietiging <strong>van</strong><br />
bosveldbome in ‘n area wat ge-oormerk is vir ‘n<br />
Oorgr<strong>en</strong>s Nasionale Park, <strong>en</strong> <strong>die</strong> moontlike impak<br />
<strong>van</strong> <strong>die</strong> myn op rivier-oewerwoud. Vyf beskermde<br />
boomspesies sou geraak word (maroela, hardekool,<br />
kremetart, witgat <strong>en</strong> appelblaar). Die Ver<strong>en</strong>iging<br />
het geregistreer as belanghebb<strong>en</strong>de instansie <strong>en</strong><br />
‘n brief gerig aan <strong>die</strong> konsultante waarin kommer<br />
oor <strong>die</strong> beoogde mynbou-aktiwiteite se pot<strong>en</strong>siële<br />
impakte uitgespreek is. Die mynbou kan deur<br />
water ontrekking, stofneerslag wat fotosintese<br />
inhibeer <strong>en</strong> grondwaterbesoedeling ‘n nadelige<br />
impak hê op bome in <strong>die</strong> rivieroewerwoud <strong>en</strong><br />
langs dreineringslope wat <strong>die</strong> Limpopo voed.<br />
Niete<strong>en</strong>staande is omgewingsgoedkeuring verle<strong>en</strong><br />
vir <strong>die</strong> beoogde mynbou.<br />
Coal Africa moes ‘n tweede omgewingsimpakstu<strong>die</strong><br />
onderneem om infrastruktuur by <strong>die</strong> Velemyn<br />
te vestig, insluit<strong>en</strong>d toegangspaaie <strong>en</strong><br />
ste<strong>en</strong>koolstoorareas. Die myn het in 2010 onwettig<br />
met <strong>die</strong> infrastruktuurontwikkeling begin sonder<br />
omgewingsgoedkeuring. Die D<strong>en</strong>drologiese<br />
Ver<strong>en</strong>iging se bestuur het <strong>die</strong> gebied laat in 2010<br />
besoek <strong>en</strong> het saam met ander NROs bygedra tot<br />
<strong>die</strong> Gro<strong>en</strong> Skerpio<strong>en</strong>e se ondersoek deur uit te wys<br />
watter beskermde boomsoorte onwettig verwyder<br />
is. Die Departem<strong>en</strong>t <strong>van</strong> Landbou, Bosbou <strong>en</strong><br />
Visserye het ‘n lis<strong>en</strong>sie vir <strong>die</strong> kap <strong>van</strong> beskermde<br />
bome toegestaan vir <strong>die</strong> mynboufase, maar nie vir<br />
<strong>die</strong> infrastruktuurontwikkeling nie. Daar is aan <strong>die</strong><br />
owerhede uitgewys dat Coal Africa <strong>die</strong> aan<strong>van</strong>klike<br />
Redakteur - nam<strong>en</strong>s <strong>die</strong> S<strong>en</strong>trale Komitee<br />
lis<strong>en</strong>sie ook verkeerdelik voorgehou het as geldig<br />
vir <strong>die</strong> infrastruktuur ontwikkeling. Wat nog meer<br />
is, daar is skade aangerig aan ‘n klein deel <strong>van</strong> <strong>die</strong><br />
rivieroewerwoud, wat beskerm is onder <strong>die</strong> Boswet.<br />
Wat <strong>die</strong> nuwe beoogde myn aan <strong>die</strong> noordelike<br />
hang <strong>van</strong> <strong>die</strong> Soutpansberg betref is ‘n lis<strong>en</strong>sie<br />
uitgereik vir <strong>die</strong> verwydering <strong>van</strong> ‘n beperkte aantal<br />
beskermde boomsoorte, insluit<strong>en</strong>d hardekool <strong>en</strong><br />
kremetart vir prospektering. Die ste<strong>en</strong>kool wat by<br />
<strong>die</strong> prospekteringsarea uitgehaal word is na <strong>die</strong><br />
Sasolaanleg in Gaut<strong>en</strong>g vervoer om <strong>die</strong> gehalte<br />
daar<strong>van</strong> te toets. ‘n Omgewingsimpakstu<strong>die</strong> sou nog<br />
gedo<strong>en</strong> word vir <strong>die</strong> beoogde mynbou indi<strong>en</strong> <strong>die</strong><br />
gehalte daar<strong>van</strong> voldo<strong>en</strong>de is.<br />
Die te<strong>en</strong>kanting te<strong>en</strong> <strong>die</strong> mynbou word gelei<br />
deur NROs soos <strong>die</strong> Natuurlewe Ver<strong>en</strong>iging wat<br />
op finansiering <strong>van</strong> borge steun <strong>en</strong> perman<strong>en</strong>te<br />
personeel in di<strong>en</strong>s het. Die D<strong>en</strong>drologiese Ver<strong>en</strong>iging<br />
word op ‘n ander wyse bedryf <strong>en</strong> met ‘n beperkte<br />
fokus op bome <strong>en</strong> boomoorheersde-ekosisteme,<br />
beskik <strong>die</strong> Ver<strong>en</strong>iging nie oor sodanige bronne <strong>en</strong><br />
personeel nie, <strong>en</strong> gaan dus ietwat anders te werk. Dit<br />
is eerst<strong>en</strong>s geskoei op <strong>die</strong> bewusmakingselem<strong>en</strong>t<br />
<strong>en</strong> bevordering <strong>van</strong> <strong>die</strong> boomwet<strong>en</strong>skap, <strong>en</strong> op<br />
meelewing <strong>van</strong> m<strong>en</strong>se met soortgelyke belange deur<br />
middel <strong>van</strong> uitstappies. Die rol wat <strong>die</strong> Ver<strong>en</strong>iging<br />
begin speel het in omgewingsimpakstu<strong>die</strong>s het maar<br />
onlangs begin, met <strong>die</strong> to<strong>en</strong>em<strong>en</strong>de aanslag <strong>van</strong><br />
ontwikkeling in natuur gebiede. Die Ver<strong>en</strong>iging is<br />
nie gekant te<strong>en</strong> ontwikkeling per se nie, maar glo dat<br />
dit op gebalanseerde wyse moet geskied, <strong>en</strong> nie in<br />
s<strong>en</strong>sitiewe gebiede nie.<br />
Die Ver<strong>en</strong>iging kan net by <strong>die</strong> mees kritieke gevalle<br />
wat bome <strong>en</strong> boomvelde raak betrokke wees, omdat<br />
deelname aan omgewingsimpakstu<strong>die</strong>s baie tyd verg,<br />
<strong>en</strong> <strong>die</strong> Ver<strong>en</strong>iging nie oor hulpbronne beskik wat in<br />
hul vrye tyd nog aktief daaraan kan deelneem nie.<br />
Deelname is ook ‘n s<strong>en</strong>sitiewe kwessie, <strong>en</strong> indi<strong>en</strong><br />
individue of takke onder <strong>die</strong> Ver<strong>en</strong>iging se naam<br />
opinies in <strong>die</strong> op<strong>en</strong>baar sou lug of briewe sou skryf<br />
kan daar pot<strong>en</strong>siële skade aan <strong>die</strong> Ver<strong>en</strong>iging se<br />
beeld gerig word indi<strong>en</strong> sodanige opinies of briewe<br />
nie weldeurdag is nie. Daarom moet standpunte <strong>en</strong><br />
skrywes deur <strong>die</strong> S<strong>en</strong>trale Komitee uitgereik, of deur<br />
<strong>die</strong> S<strong>en</strong>trale Komitee ondersteun word alvor<strong>en</strong>s dit<br />
op<strong>en</strong>baar gemaak word.<br />
MYNBOU IN LIMPOPO PROVINSIE<br />
VERNIETIGING VAN DIE MOPANIEBOS NABY MAPUNGUBWE » Foto Naas Grové<br />
review<br />
review<br />
35<br />
DENDRON » No/Nr: 43 » November 2011
DENDRON » No/Nr: 43 » November 2011<br />
36<br />
review<br />
review<br />
CLASSIFICATION AND NOMENCLATURE OF THE GENUS ACACIA<br />
Classification and nom<strong>en</strong>clature<br />
of the g<strong>en</strong>us Acacia (Leguminosae), with emphasis on Africa<br />
Abstract<br />
The widespread and well-known g<strong>en</strong>us Acacia<br />
has experi<strong>en</strong>ced a huge amount of taxonomic<br />
turmoil over the past <strong>co</strong>uple of decades. In this<br />
<strong>co</strong>ntribution the nom<strong>en</strong>clatural history of Acacia is<br />
outlined. Evid<strong>en</strong>ce for the rec<strong>en</strong>t split of the g<strong>en</strong>us<br />
into five segregate g<strong>en</strong>era is provided and the<br />
retypification from the African species A. nilotica to<br />
the Australian A. p<strong>en</strong>ninervis is discussed critically.<br />
The International Code for Botanical Nom<strong>en</strong>clature<br />
(ICBN) is introduced and discussed as a set of<br />
guidelines for taxonomic change. Lastly, some ideas<br />
are provided for plant name users of how to deal<br />
with this nom<strong>en</strong>clatural in<strong>co</strong>nv<strong>en</strong>i<strong>en</strong>ce.<br />
“No other taxonomic proposal<br />
has ever had the pot<strong>en</strong>tial for<br />
disruption to nom<strong>en</strong>clature on a<br />
<strong>co</strong>ntin<strong>en</strong>tal scale as the one to split<br />
Acacia.” – Orchard & Maslin 2005<br />
1. Introduction<br />
Convincing evid<strong>en</strong>ce has be<strong>en</strong> accumulating<br />
over the past two to three decades that the large,<br />
well-known and charismatic g<strong>en</strong>us Acacia Mill. is<br />
polyphyletic (Maslin et al. 2003; Orchard & Maslin<br />
2003). Polyphyletic refers to a group derived from<br />
differ<strong>en</strong>t <strong>co</strong>mmon ancestors. The ideal in plant<br />
classifcation is to re<strong>co</strong>gnize monophyletic groups.<br />
In the case of a monophyletic group all members<br />
are derived from the same rec<strong>en</strong>t <strong>co</strong>mmon ancestor.<br />
Many taxonomic workers now agree that Acacia<br />
s<strong>en</strong>so lato (as traditionally defined), meaning Acacia<br />
in a broad s<strong>en</strong>se, should in fact be five segregate<br />
g<strong>en</strong>era, because five separate monophyletic groups<br />
can be re<strong>co</strong>gnised within the g<strong>en</strong>us (Maslin et al.<br />
2003). In 2005 the g<strong>en</strong>us was split and retypified<br />
in ac<strong>co</strong>rdance to Proposal 1584 by Orchard &<br />
Maslin (2003). This caused a plant nom<strong>en</strong>clatural<br />
uproar, the likes of which had never be<strong>en</strong> se<strong>en</strong> and<br />
hopefully will never be se<strong>en</strong> again. The aim of this<br />
<strong>co</strong>ntribution is to review the developm<strong>en</strong>ts in Acacia<br />
s.l. phylog<strong>en</strong>y and its impacts on the classification<br />
and the nom<strong>en</strong>clature of the group, with emphasis<br />
on Africa. I will further attempt to critically evaluate<br />
the split and retypification of the g<strong>en</strong>us and provide<br />
William a. Haddad<br />
some thoughts on how to <strong>co</strong>pe with this great<br />
nom<strong>en</strong>clatural in<strong>co</strong>nv<strong>en</strong>i<strong>en</strong>ce.<br />
2. Background on the g<strong>en</strong>us Acacia<br />
Although the palaeobotanical evid<strong>en</strong>ce is<br />
in<strong>co</strong>nclusive, it is g<strong>en</strong>erally believed that the g<strong>en</strong>us<br />
Acacia s.l. evolved in the tropical lowland forests<br />
of West Gondwana, but there is no agreem<strong>en</strong>t as<br />
to which section should be <strong>co</strong>nsidered ancestral.<br />
The various sections in exist<strong>en</strong>ce today must<br />
have evolved from the original form in se<strong>co</strong>ndary<br />
c<strong>en</strong>tres where the climatic or edaphic factors<br />
were differ<strong>en</strong>t (Ross 1979). The oldest Acacia s.l.<br />
fossil was found in Tan<strong>za</strong>nia and dated at 46 mya<br />
(Bouch<strong>en</strong>ak-Khelladi et al. 2010).<br />
The highly <strong>co</strong>mplex nom<strong>en</strong>clatural history<br />
(outlined in Table 1) of the g<strong>en</strong>us Acacia s.l.<br />
started with its formal description by Phillip<br />
Miller in 1754. It was not until 1842, however, that<br />
the g<strong>en</strong>eric limits were clearly defined by George<br />
B<strong>en</strong>tham by restricting the name to mimosoid<br />
plants with numerous free stam<strong>en</strong>s (Maslin et<br />
al. 2003). The g<strong>en</strong>us was only typified in 1913<br />
by Britton and Brown to the African species A.<br />
s<strong>co</strong>rpioides (L.) W.Wight (=A. nilotica (L.) Delile).<br />
Since that time many authors have proposed<br />
differ<strong>en</strong>t ways to subdivide the g<strong>en</strong>us, making use<br />
of various differ<strong>en</strong>t characters (B<strong>en</strong>tham 1875;<br />
Ross 1979; Vassal 1981; Pedley 1986; Orchard &<br />
Maslin 2003).<br />
Acacia, in the broad s<strong>en</strong>se, is the se<strong>co</strong>nd largest<br />
g<strong>en</strong>us in the family Leguminosae (Fabaceae s.l.)<br />
or the largest g<strong>en</strong>us in the family Mimosaceae,<br />
if <strong>co</strong>nsidered under an alternate classification<br />
system, with about 1540 living taxa (specific<br />
& intra-specific)(Orchard & Maslin 2005). It is<br />
widely distributed across the world’s tropics and<br />
sub-tropical zones with c<strong>en</strong>tres of diversity in<br />
Australia (± 1000 species), the Americas (±180<br />
species), Africa (± 160 species), Asia (±100<br />
species) and a <strong>co</strong>uple of species on the Pacific<br />
Islands (Thiele et al. 2011) (Figure 1). As of yet,<br />
there are no explanations for this remarkably<br />
disjunct geographic distribution (Bouch<strong>en</strong>ak-<br />
Khelladi et al. 2010). Ross (1979) describes the<br />
e<strong>co</strong>logical role of Acacia s.l. very satisfactorily:<br />
“There is probably no group of trees or shrubs<br />
in Africa that can rival Acacia in the <strong>co</strong>mbined<br />
importance of its e<strong>co</strong>logy and ext<strong>en</strong>t of its<br />
geographical range. Almost everywhere from<br />
South Africa northwards to the Mediterranean,<br />
where the climate is reasonably dry, there will<br />
CLASSIFICATION AND NOMENCLATURE OF THE GENUS ACACIA<br />
Year Nom<strong>en</strong>clatural Ev<strong>en</strong>t Key Refer<strong>en</strong>ce<br />
1754 G<strong>en</strong>us Acacia described. Miller (1754)<br />
1842 G<strong>en</strong>eric limits defined<br />
1875 Considered one g<strong>en</strong>us with six series. B<strong>en</strong>tham (1875)<br />
1913 G<strong>en</strong>us Acacia typified to A. nilotica.<br />
1981 Considered as one g<strong>en</strong>us with three subg<strong>en</strong>era. Vassal (1981)<br />
1986 Proposal to raise subg<strong>en</strong>era to three individual g<strong>en</strong>era. Pedley (1986)<br />
2003<br />
Proposal 1584 to split g<strong>en</strong>us into five g<strong>en</strong>era and to move the type of<br />
name Acacia to A. p<strong>en</strong>ninervis.<br />
Orchard & Maslin<br />
(2003)<br />
2004 The IAPT Committee for Spermatophyta re<strong>co</strong>mm<strong>en</strong>ds proposal 1584. Brummitt (2004)<br />
2005<br />
2011<br />
Proposal 1584 is <strong>co</strong>ntroversially accepted at the nom<strong>en</strong>clature<br />
section of the 16th IBC in Vi<strong>en</strong>na. The type is moved and five differ<strong>en</strong>t<br />
g<strong>en</strong>era are now re<strong>co</strong>gnized.<br />
An attempt is made at the 17th IBC in Melbourne to overturn the<br />
decisions made in Vi<strong>en</strong>na. The attempt failed and the type remains an<br />
Australian species.<br />
TABLE 1.– Simplified nom<strong>en</strong>clatural history of the g<strong>en</strong>us Acacia.<br />
180<br />
160<br />
Acacia be found, usually frequ<strong>en</strong>tly and oft<strong>en</strong> in<br />
dominant abundance. Only in the evergre<strong>en</strong> forest<br />
regions of Africa do Acacia play a <strong>co</strong>mparatively<br />
subordinate role”.<br />
100<br />
1000<br />
review<br />
review<br />
FIGURE 1.– Distribution map showing the range of Acacia s.l. with approximated numbers of <strong>en</strong>demic taxa<br />
per <strong>co</strong>ntin<strong>en</strong>t. Image from www.worldwidewattle.<strong>co</strong>m and data from Thiele et al. (2011).<br />
37<br />
DENDRON » No/Nr: 43 » November 2011
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38<br />
review<br />
review<br />
The traditional classification of Acacia s.l. was based<br />
mainly on the ideas of B<strong>en</strong>tham (1875) who <strong>co</strong>nsidered<br />
it to be a single g<strong>en</strong>us, <strong>co</strong>ntaining six series. The most<br />
widely used rec<strong>en</strong>t classification is that of Vassal<br />
(1981)—one g<strong>en</strong>us, three subg<strong>en</strong>era (see Table 2).<br />
In 1986 Pedley proposed that the three subg<strong>en</strong>era<br />
should each be raised to g<strong>en</strong>eric rank, namely<br />
Acacia, S<strong>en</strong>egalia Raf. and Ra<strong>co</strong>sperma Mart. (Table<br />
2), but taxonomists have be<strong>en</strong> reluctant to accept<br />
this classification because of an appreh<strong>en</strong>sion of the<br />
nom<strong>en</strong>clatural turmoil that it would <strong>en</strong>tail (Orchard<br />
& Maslin 2003). Rec<strong>en</strong>t taxonomic work done on<br />
the g<strong>en</strong>us and its relatives in the tribes Ingeae and<br />
Mimoseae have greatly expanded our knowledge of<br />
the groups, however (Maslin et al. 2003). This includes<br />
evid<strong>en</strong>ce from morphology, palynology, biochemistry,<br />
molecular and cladistic stu<strong>die</strong>s and led to a g<strong>en</strong>eral<br />
Pre- Vi<strong>en</strong>na ICB names<br />
(A. nilotica as type)<br />
Acacia<br />
CLASSIFICATION AND NOMENCLATURE OF THE GENUS ACACIA<br />
Pedley’s classification<br />
3. Role of the ICBN<br />
It is important at this stage, before we <strong>co</strong>ntinue to<br />
the discussion on the modern <strong>co</strong>ntroversies around<br />
the name Acacia, to define clearly the terminology<br />
used in the field of systematics. Ac<strong>co</strong>rding to the<br />
13 th Edition of H<strong>en</strong>derson’s dictionary of biology<br />
(Lawr<strong>en</strong>ce 2005), systematics is the study of the<br />
id<strong>en</strong>tification, taxonomy and nom<strong>en</strong>clature of<br />
organisms, including the classification of living things<br />
with regard to their natural relationships. Taxonomy<br />
is the analysis of an organism’s characteristics for<br />
the purpose of classification, whereas classification<br />
is the arrangem<strong>en</strong>t of living organisms into<br />
groups on the basis of observed similarities and<br />
differ<strong>en</strong>ces. Most modern classification systems<br />
try to reflect degrees of evolutionary relatedness<br />
(Lawr<strong>en</strong>ce 2005). Id<strong>en</strong>tification is the process of<br />
associating an unknown taxon with a known one or<br />
the re<strong>co</strong>gnition that the unknown is new to sci<strong>en</strong>ce<br />
and the assignm<strong>en</strong>t of names using a formal system<br />
belief among taxonomic workers that Acacia s.l.<br />
should in fact be five segregate g<strong>en</strong>era (Orchard &<br />
Maslin 2005).<br />
In 2005 Orchard & Maslin described these five<br />
groups as follows (Table 2): “The largest of these,<br />
with about 960 species is the curr<strong>en</strong>t A. subg.<br />
Phyllodineae (DC.) Ser. (= subg. Heterophyllum<br />
Vassal), for which the name Ra<strong>co</strong>sperma is available.<br />
The next largest is A. subg. Aculeiferum Vassal with<br />
about 203 species, and for which the name S<strong>en</strong>egalia<br />
is available. The third major group, pres<strong>en</strong>tly known<br />
as A. subg. Acacia, <strong>co</strong>ntains about 161 species,<br />
including the curr<strong>en</strong>t type of Acacia, A. nilotica.<br />
The name Vachellia is available for this group. The<br />
remaining two groups are small and <strong>co</strong>mpromise 15<br />
and 13 species respectively.” These last two smaller<br />
groups arise from within A. subg. Aculeiferum.<br />
With retypification<br />
(A. p<strong>en</strong>ninervis as type)<br />
Post- Vi<strong>en</strong>na ICB names<br />
Without retypification<br />
(A. nilotica as type)<br />
subg. Acacia Acacia Vachellia Acacia<br />
subg. Aculeiferum S<strong>en</strong>egalia<br />
sect. Spiciflorae S<strong>en</strong>egalia S<strong>en</strong>egalia<br />
sect. Filicinae Acaciella Acaciella<br />
A.<strong>co</strong>ulteri group Mariosousa Mariosousa<br />
subg. Phyllodineae Ra<strong>co</strong>sperma Acacia Ra<strong>co</strong>sperma<br />
TABLE 2.– Summery of the various classification systems used for the g<strong>en</strong>us Acacia s.l.<br />
is called nom<strong>en</strong>clature (Simpson 2006).<br />
Sci<strong>en</strong>tific nom<strong>en</strong>clature allows people to<br />
<strong>co</strong>mmunicate about organisms and to store and<br />
retrieve information about these organisms.<br />
Simpson (2006) summarises the need for names<br />
well: “Botanical names serve as symbols of a group<br />
of natural <strong>en</strong>tities for the purpose of <strong>co</strong>mmunication<br />
and data refer<strong>en</strong>ce.”, while the preface to the 2005<br />
International Code for Botanical Nom<strong>en</strong>clature<br />
(ICBN) (available at http://ibot.sav.sk/icbn/main.<br />
htm) states that “Unambiguous names for organisms<br />
are ess<strong>en</strong>tial for effective sci<strong>en</strong>tific <strong>co</strong>mmunication<br />
(and) names can only be unambiguous if there<br />
are internationally accepted rules governing their<br />
formation and use.” Nom<strong>en</strong>clature and classification<br />
systems are working tools and should be as stable<br />
as possible, because if it changes <strong>co</strong>ntinually, it<br />
will cease to be meaningful. Taxonomists, however,<br />
have be<strong>en</strong> criticized for changing too many things<br />
too oft<strong>en</strong> (Orchard & Maslin 2005). In an attempt<br />
to stabilize and regulate plant nom<strong>en</strong>clature, the<br />
International Code for Botanical Nom<strong>en</strong>clature<br />
(ICBN) has be<strong>en</strong> developed over decades in order<br />
to try to increase stability of names. Several articles<br />
of the <strong>co</strong>de have be<strong>en</strong> designed and in<strong>co</strong>rporated<br />
specifically to help facilitate the <strong>co</strong>nservation of<br />
names in order to minimise name changes (see Box<br />
1 for examples of <strong>co</strong>nserved names in use today).<br />
Conserved Name Reason for Conservation Key Refer<strong>en</strong>ce<br />
Hedysarum<br />
(Leguminosae: Papilionoideae)<br />
Leuca<strong>en</strong>a<br />
(Leguminosae: Papilionoideae)<br />
C<strong>en</strong>taurea<br />
(Asteraceae)<br />
Bossiea<br />
(Leguminosae)<br />
Research showed that the name<br />
Hedysarum would be restricted to<br />
H. subg. Hedysarum, <strong>co</strong>ntaining<br />
only six species. A new name will<br />
th<strong>en</strong> be required for the remaining<br />
members of Hedysarum s.l.—<br />
approximately 100 species.<br />
Leuca<strong>en</strong>a was <strong>co</strong>nserved to a new<br />
type wh<strong>en</strong> it was dis<strong>co</strong>vered that<br />
the basionym of the previously<br />
accepted type belonged to<br />
Acacia. This would have caused<br />
Leuceana to be<strong>co</strong>me a synonym<br />
of Acacia.<br />
The accepted type of C<strong>en</strong>taurea<br />
was dis<strong>co</strong>vered to belong to a<br />
small group of about 32 species<br />
earmarked for segregation to<br />
Bielzia. The remaining 400–700<br />
species thus needed new names.<br />
Bossiae (59 spp.) and Platylobium<br />
(4 spp.) are to be merged, but<br />
Platylobium has priority of<br />
publication. The <strong>co</strong>nservation of<br />
Bossiae would thus be better for<br />
nom<strong>en</strong>clatural stability.<br />
BOX 1.– Examples of other successfully retypified and <strong>co</strong>nserved names.<br />
4. Evid<strong>en</strong>ce for splitting the g<strong>en</strong>us<br />
It has long be<strong>en</strong> known, or at least strongly suspected,<br />
by many taxonomic workers that the g<strong>en</strong>us Acacia s.l.<br />
is polyphyletic (Pedley 1986; Orchard & Maslin 2003).<br />
This means that the g<strong>en</strong>us is actually an artificial<br />
<strong>co</strong>nstruct <strong>co</strong>nsisting out of several fairly unrelated<br />
g<strong>en</strong>era. While the majority of Acacia s.l. species are<br />
characterized by numerous free filam<strong>en</strong>ts, there<br />
are no synapomorphic characters that support their<br />
positioning as a natural group (Kergoat et al. 2006). The<br />
curr<strong>en</strong>t view is that the group should be divided into<br />
five separate g<strong>en</strong>era in order to satisfy the requirem<strong>en</strong>t<br />
of monophyly. In the following subsections, evid<strong>en</strong>ce is<br />
provided for the five g<strong>en</strong>era point of view.<br />
4.1 Established evid<strong>en</strong>ce<br />
The idea that Acacia s.l. is not a homog<strong>en</strong>eous<br />
group is not new. A 1979 review by Ross outlined<br />
CLASSIFICATION AND NOMENCLATURE OF THE GENUS ACACIA<br />
The ICBN regulates primarily two basic activities,<br />
namely (1) the naming of new, undescribed or<br />
unnamed taxa and (2) <strong>co</strong>rrectly r<strong>en</strong>aming previously<br />
named taxa which have be<strong>en</strong> divided, united,<br />
transferred or changed in rank. It is this se<strong>co</strong>nd<br />
activity that we are interested in in this case, as the<br />
g<strong>en</strong>us Acacia has be<strong>en</strong> changed in rank.<br />
Choi & Ohashi (1998)<br />
Hughes (1997)<br />
Greuter et al. (2001)<br />
Ross (2004)<br />
review<br />
review<br />
many differ<strong>en</strong>ces betwe<strong>en</strong> the two mainly African<br />
subg<strong>en</strong>era of Acacia s.l., based on morphology,<br />
palynology, g<strong>en</strong>etics, anatomy and biochemistry<br />
(Table 3). It is expected that there would be an<br />
ev<strong>en</strong> number, if not greater number, of differ<strong>en</strong>ces<br />
betwe<strong>en</strong> the African and Australian subg<strong>en</strong>era<br />
based on these criteria, but literature on this <strong>co</strong>uld<br />
not be accessed.<br />
It is easy to see how these groups <strong>co</strong>uld have be<strong>en</strong><br />
lumped together for so long. Consider for example<br />
the thorns: One can easily mistake the pres<strong>en</strong>ce<br />
of thorns in both groups as a <strong>co</strong>mmon character,<br />
but on closer inspection it turns out that they are<br />
not homologous. In Vachellia the thorns are in<br />
fact spines derived from the stipules, where as in<br />
S<strong>en</strong>egalia, they are prickles derived from epidermal<br />
outgrowths. These two seemingly similar characters<br />
thus repres<strong>en</strong>t a very differ<strong>en</strong>t evolutionary history.<br />
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review<br />
Morphology<br />
Vachellia<br />
1. Capitate infloresc<strong>en</strong>ces (bright gold<strong>en</strong> yellow with<br />
some pale-yellow to white).<br />
2. Stipules spinesc<strong>en</strong>t.<br />
3. Seeds with large areoles that <strong>co</strong>nform to the<br />
outline of the seed shape.<br />
4. Developm<strong>en</strong>t of fascicular se<strong>co</strong>ndary leaves.<br />
5. Infloresc<strong>en</strong>ces have an involucel on the peduncle.<br />
6. Ovaries sessile or sub-sessile with no disc<br />
(nectary).<br />
7. Floral bracts persist to seed set.<br />
8. Pod pericarp <strong>co</strong>nsists of only longitudinal fibres,<br />
or is abs<strong>en</strong>t.<br />
9. Differ<strong>en</strong>ces in pod v<strong>en</strong>ation.<br />
Palynology<br />
10. Poll<strong>en</strong> grain with furrows on the surface.<br />
anatomy<br />
11. Differ<strong>en</strong>ces betwe<strong>en</strong> petioles.<br />
12. Differ<strong>en</strong>ces in ontog<strong>en</strong>y of stipule tissues.<br />
13. Anatomy of leaflet tissue types differ.<br />
14. Differ<strong>en</strong>ces betwe<strong>en</strong> seed <strong>co</strong>ats.<br />
G<strong>en</strong>etics<br />
15. Diploid chromosome number of 2n=52.<br />
16. Differ<strong>en</strong>ces betwe<strong>en</strong> nucleolar diameters and<br />
chromatin l<strong>en</strong>gths.<br />
Biochemistry<br />
CLASSIFICATION AND NOMENCLATURE OF THE GENUS ACACIA<br />
17. A very distinctive amino acid distribution found in<br />
the seeds.<br />
18. Seeds <strong>co</strong>ntain unusual amino acids that are not<br />
pres<strong>en</strong>t in the other group.<br />
19. Gum has a higher molecular weight-vis<strong>co</strong>sity than<br />
the other group.<br />
20. Heartwood has flavonoids of the resorcinol A-ring<br />
group.<br />
Morphology<br />
S<strong>en</strong>egalia<br />
1. Spicate infloresc<strong>en</strong>ces (pale-yellow to white<br />
flowers).<br />
2. Stipules non-spinesc<strong>en</strong>t.<br />
3. Seeds with small horseshoe-shaped c<strong>en</strong>tral<br />
areoles.<br />
4. No developm<strong>en</strong>t of fascicular se<strong>co</strong>ndary leaves.<br />
5. Infloresc<strong>en</strong>ces do not have an involucel on the<br />
peduncle.<br />
6. Pedicellate ovaries with a cup shaped disc<br />
(nectary).<br />
7. Floral bracts shed before flower op<strong>en</strong>s.<br />
8. Pod pericarp <strong>co</strong>nsists of longitudinal and<br />
latitudinal fibres.<br />
9. Differ<strong>en</strong>ces in pod v<strong>en</strong>ation.<br />
Palynology<br />
10. Poll<strong>en</strong> grains without furrows on the surface.<br />
anatomy<br />
11. Differ<strong>en</strong>ces betwe<strong>en</strong> petioles.<br />
12. Differ<strong>en</strong>ces in ontog<strong>en</strong>y of stipule tissues.<br />
13. Anatomy of leaflet tissue types differ.<br />
14. Differ<strong>en</strong>ces betwe<strong>en</strong> seed <strong>co</strong>ats<br />
G<strong>en</strong>etics<br />
15. Diploid chromosome number of 2n=26.<br />
16. Differ<strong>en</strong>ces betwe<strong>en</strong> nucleolar diameters and<br />
chromatin l<strong>en</strong>gths.<br />
Biochemistry<br />
17. Not a distinctive amino acid distribution in the<br />
seeds.<br />
18. Seeds <strong>co</strong>ntain unusual amino acids that are not<br />
pres<strong>en</strong>t in the other group.<br />
19. Gum has a lower molecular weight-vis<strong>co</strong>sity than<br />
the other group.<br />
20. Heartwood has flavonoids of the pyrogallol A-ring<br />
group.<br />
TABLE 3.– Differ<strong>en</strong>ces betwe<strong>en</strong> the two mainly African groupings of Acacia s.l. now known as Vachellia<br />
and S<strong>en</strong>egalia, as summarized by Ross (1979). (Exceptions to these tr<strong>en</strong>ds exist, but they are few and<br />
many can be explained as hybridi<strong>za</strong>tion ev<strong>en</strong>ts or rec<strong>en</strong>t <strong>co</strong>nverg<strong>en</strong>ce.)<br />
4.2 Rec<strong>en</strong>t evid<strong>en</strong>ce<br />
The evid<strong>en</strong>ce in Table 3 was not <strong>en</strong>ough, however,<br />
to <strong>co</strong>nvince people to take up classifications splitting<br />
Acacia s.l. into differ<strong>en</strong>t g<strong>en</strong>era (such as that of Pedley<br />
(1986)). It is only rec<strong>en</strong>tly that the world of systematics<br />
has be<strong>co</strong>me more inclined to embark upon the<br />
huge taxonomic <strong>en</strong>deavour of splitting this large<br />
g<strong>en</strong>us—fuelled primarily by a large quantity of sound<br />
phylog<strong>en</strong>etic evid<strong>en</strong>ce using molecular markers<br />
(Kergoat et al. 2006).<br />
Probably the most <strong>co</strong>mpreh<strong>en</strong>sive phylog<strong>en</strong>etic study<br />
done on the acacias and its relatives in the tribes<br />
Acacieae, Ingeae and Mimoseae, is that of Bouch<strong>en</strong>ak-<br />
Khelladi et al. (2010). They found that Mimosoideae is<br />
monophyletic, but that the distinction betwe<strong>en</strong> the taxa<br />
within this subfamily is not well defined and should be<br />
investigated further. In addition, they found that the<br />
tribe Mimoseae is paraphyletic because Vachellia, a<br />
member of the tribe Acacieae, nests within it. This led<br />
them to believe that, despite being characterized by<br />
synapomorphic characters, the tribe does not share<br />
a <strong>co</strong>mmon ancestor. Vachellia, S<strong>en</strong>egalia, Mariosousa<br />
and Acaciella are all supported as monophyletic<br />
groups, but Vachellia is <strong>co</strong>nsidered to be basal while<br />
S<strong>en</strong>egalia, Mariosousa and Acaciella are more derived<br />
and repres<strong>en</strong>tative of early-diverging lineages from<br />
the Ingeae and Acacia s.s. clade. Although their<br />
phylog<strong>en</strong>etic relationships are not yet resolved, the<br />
tribe Ingeae and Acacia s.s. form a monophyletic<br />
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group. All these relationships are illustrated in Figure<br />
2, a simplified version of the phylog<strong>en</strong>etic tree by<br />
Bouch<strong>en</strong>ak-Khelladi et al. (2010).<br />
Kergoat et al. (2006) attempted to use alternative<br />
sources of information to provide additional insights<br />
into Acacia s.l. systematics. They argued that<br />
phytophagous insect species that are obligate feeders<br />
on a restricted number of host plant taxa should display<br />
a similar evolutionary pattern to that of the host plant.<br />
This pattern is termed ‘taxonomic <strong>co</strong>nservationism in<br />
host plant use’. Kergoatet al. (2006) was particularly<br />
interested in the specialized seed-beetles or Bruchid<br />
beetles (Coleoptera, Chrysomelidae, Bruchinae)<br />
because they g<strong>en</strong>erally exhibit a strong level of<br />
taxonomic <strong>co</strong>nservationism in host-plant use and are<br />
known to develop in Acacia s.l. seeds.<br />
It was found that species of the bruchid g<strong>en</strong>era<br />
Acanthoscelides, Mimosestes and Bruchidius clade<br />
II are prefer<strong>en</strong>tially associated with Vachellia and<br />
members of the tribes Cassieae and Ceasalpinieae.<br />
Species of Merobruchus feed almost exclusively on<br />
Acacia s.s., Acaciella, Mariosousa and S<strong>en</strong>egalia as<br />
CLASSIFICATION AND NOMENCLATURE OF THE GENUS ACACIA<br />
review<br />
review<br />
well as members of the tribe Ingeae. Lastly, Stator<br />
and Bruchidius clade I species are able to feed on a<br />
much larger set of host plants including both Vachellia<br />
and other Acacia s.l. species (Kergoat et al. 2006).<br />
The phylog<strong>en</strong>y of Mimosoideae seed predators thus<br />
support the phylog<strong>en</strong>y depicted in Figure 2 and the<br />
idea that Acacia s.l. is paraphyletic. Some groups of<br />
beetles are associated only with the basal Vachellia,<br />
Cassieae and Ceasalpinieae, while others are<br />
associated with the more derived Acacia s.s., Acaciella,<br />
Mariosousa, S<strong>en</strong>egalia and Ingeae.<br />
Further noteworthy observations from the Kergoat<br />
et al. (2006) study are that the patterns of host-plant<br />
associations seem to be strongly mutually exclusive.<br />
In other words, predators that feed on Vachellia<br />
and Ceasalpinieae seed will not feed on Acacia<br />
s.s., Acaciella, Mariosousa and S<strong>en</strong>egalia seed and<br />
vice versa. Also, species of seed predators that are<br />
associated only with Vachellia are closely related,<br />
suggesting a <strong>co</strong>nservative host shift to the g<strong>en</strong>us.<br />
From all the above m<strong>en</strong>tioned evid<strong>en</strong>ce it is thus<br />
41<br />
DENDRON » No/Nr: 43 » November 2011
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42<br />
review<br />
review<br />
CLASSIFICATION AND NOMENCLATURE OF THE GENUS ACACIA<br />
clear that Acacia s.l. is a very heterog<strong>en</strong>eous group<br />
and that it would make s<strong>en</strong>se to divide it into five<br />
more homog<strong>en</strong>eous g<strong>en</strong>era, because it would greatly<br />
improve the stability and predictive capabilities of<br />
the classification system. The split would however<br />
negatively affect our ability to access information on<br />
the taxa that now use new names, because a name<br />
acts as a key to accessing information. But over time<br />
and with the <strong>co</strong>rrect use of synonyms, this problem<br />
will be<strong>co</strong>me less pronounced. Moving the type<br />
specim<strong>en</strong> from the African A. nilotica to the Australian<br />
A. p<strong>en</strong>ninervis, however, was a much more <strong>co</strong>nt<strong>en</strong>tious<br />
and hotly debated proposal. The argum<strong>en</strong>t for and<br />
against this move is discussed in the next section.<br />
Acacia s.s<br />
Ingeae<br />
Acaciella<br />
Mariosousa<br />
S<strong>en</strong>egalia<br />
Mimoseae<br />
Vachellia<br />
Mimoseae<br />
Caesalpinieae<br />
FIGURE 2.– Simplified phylog<strong>en</strong>etic tree of the<br />
five g<strong>en</strong>era within Acacia s.l. and tribes Ingeae,<br />
Mimoseae and Caesalpinieae. Adapted from<br />
Bouch<strong>en</strong>ak-Khelladi et al. (2010).<br />
5. Retypification<br />
Splitting the g<strong>en</strong>us Acacia into five segregate g<strong>en</strong>era<br />
means that only one of the five newly delimited<br />
g<strong>en</strong>era can keep the g<strong>en</strong>eric name of Acacia.<br />
Post-Vi<strong>en</strong>na ICB names<br />
(A. p<strong>en</strong>ninervis as type)<br />
Ac<strong>co</strong>rding to the ICBN the group that <strong>co</strong>ntains<br />
the type specim<strong>en</strong> of the name gets to keep that<br />
particular name. In the case of Acacia, the g<strong>en</strong>eric<br />
type was A. nilotica, a member of A. subg. Acacia,<br />
<strong>co</strong>ntaining ca 160 taxa. This meant that once the<br />
g<strong>en</strong>us was split, only some 12% of the more than<br />
1400 species of Acacia s.l. will still be able to use<br />
the name (see Table 4). Orchard and Maslin (2003)<br />
proposed to move the g<strong>en</strong>eric type specim<strong>en</strong> of<br />
g<strong>en</strong>us Acacia to a member of the largest splinter<br />
group, A. p<strong>en</strong>ninervis of the subg. Phyllodineae. This<br />
would <strong>en</strong>sure that about 72% of the original Acacia<br />
s.l. species can keep using the name Acacia. Wh<strong>en</strong><br />
just <strong>co</strong>nsidering pure numbers, retypification looks<br />
like a brilliant idea and it is difficult to think how<br />
anyone can disagree with it, but the retypification of<br />
Acacia was probably one of the most hotly debated<br />
issues in modern plant taxonomy. See also Box 1<br />
for other examples of retypification and Table 1 for<br />
dates of retypification.<br />
As a result of the g<strong>en</strong>eric split, about half of Africa’s<br />
thorn trees will be<strong>co</strong>me S<strong>en</strong>egalia. The <strong>co</strong>ntest for<br />
use of the g<strong>en</strong>eric name Acacia is thus restricted<br />
to A. subg<strong>en</strong>era Acacia and Phyllodineae. Because<br />
A. subg. Phyllodineaea has a near exclusive<br />
Australian distribution and A. subg. Acacia is<br />
strongly associated with especially Africa, but also<br />
South America, this became an ‘Australia versus<br />
the rest of the world’ debate. Most of the argum<strong>en</strong>ts<br />
for and against retypification are summarised in<br />
Table 5 while some of the more important ones are<br />
discussed in more detail below.<br />
Retypification is a well tried and accepted procedure<br />
allowed by the ICBN and the preced<strong>en</strong>t exists that<br />
the name of a large g<strong>en</strong>us should be <strong>co</strong>nserved to<br />
ad<strong>van</strong>ce nom<strong>en</strong>clatural stability in such cases (see<br />
Box 1 for examples). Luckow et al. (2005) however<br />
argue that each case should be examined carefully, in<br />
particular the impact on the taxon that stands to lose<br />
Sp. numbers and distribution<br />
Americas Africa Asia Australia Total<br />
Vachellia 52 83 32 9 163<br />
S<strong>en</strong>egalia 79 74 48 2 194<br />
Acaciella 15 0 0 0 15<br />
Mariosousa 13 0 0 0 13<br />
Acacia 0 1 12 1017 1021<br />
Total 161 158 92 1028 1406<br />
TABLE 4.– Species numbers of Acacia s.l. members <strong>co</strong>rresponding to geographic areas of major<br />
occurr<strong>en</strong>ce. Adapted from Thiele et al. (2011).<br />
CLASSIFICATION AND NOMENCLATURE OF THE GENUS ACACIA<br />
PAPER-BARK THORN, Acacia sieberiana subsp. woodii – LESHIBA WILDERNESS » Photo: Naas Grové<br />
the use of the original type. They quote from a paper<br />
by McNeill et al. (2003) on the <strong>co</strong>nservation of names:<br />
“Committees will not be sympathetic to proposals to<br />
avoid disad<strong>van</strong>tageous change in usage in one part of<br />
the world at the exp<strong>en</strong>se of creating disad<strong>van</strong>tageous<br />
change in another. These situations are what the<br />
principles of priority are for”. Basically, Luckow et<br />
al. (2005) said that with such a <strong>co</strong>ntroversial, ev<strong>en</strong>ly<br />
<strong>co</strong>ntested and emotionally loaded question, such as<br />
that of Acacia, the principle of priority should prevail.<br />
The argum<strong>en</strong>t for or against retypification should not be<br />
based purely on numbers, but the share of the world’s<br />
population that would be affected by such changes<br />
should also be <strong>co</strong>nsidered. Although Acacia s.s. is very<br />
speciose and <strong>co</strong>ntains about 72% of Acacia s.l. taxa,<br />
the majority of these species are narrow <strong>en</strong>demics,<br />
while Vachellia has a much wider distribution (Luckow<br />
et al. 2005). Thus the change to Vachellia will affect<br />
more people in more <strong>co</strong>untries around the world than<br />
the change to Ra<strong>co</strong>sperma will, ev<strong>en</strong> if there are about<br />
six times more taxa in Ra<strong>co</strong>sperma than Vachellia.<br />
Orchard & Maslin (2005) are of the opinion that gross<br />
numbers are very important, irrespective of the<br />
distribution of individual taxa. They argue that while<br />
widespread species may impact on more floras, rare<br />
species will feature much more widely in <strong>co</strong>nservation<br />
literature and legislation.<br />
Another important focal point in the argum<strong>en</strong>t for<br />
or against retypification was that of e<strong>co</strong>nomic and<br />
e<strong>co</strong>logical importance of the two groups in question.<br />
review<br />
review<br />
Many acacias of e<strong>co</strong>nomic importance are of the subg.<br />
Phyllodineae and are grown in more than 70 <strong>co</strong>untries<br />
where they are estimated to <strong>co</strong>ver over 2 million<br />
hectares in <strong>co</strong>mmercial plantations (Orchard & Maslin<br />
2003). There are thus many <strong>co</strong>untries, industries<br />
and activities that are affected by the change to<br />
Ra<strong>co</strong>sperma. Weed managem<strong>en</strong>t, floriculture, forestry<br />
(timber, pulp, tannins and fuel wood) agriculture and<br />
land rehabilitation to name a few. In terms of e<strong>co</strong>logical<br />
importance, it is very difficult to <strong>co</strong>mpare two differ<strong>en</strong>t<br />
groups from two differ<strong>en</strong>t <strong>co</strong>ntin<strong>en</strong>ts with one another.<br />
There are many varied views in the literature as<br />
to which group is more important to its respective<br />
<strong>co</strong>ntin<strong>en</strong>t, but I am of the opinion that we cannot make<br />
such a call based on curr<strong>en</strong>t knowledge.<br />
Lastly, an oft<strong>en</strong> over looked fact is that the use of<br />
Ra<strong>co</strong>sperma would be unfortunate as the g<strong>en</strong>der will<br />
change from feminine (Acacia) to neuter (Ra<strong>co</strong>sperma)<br />
and this will affect the specific epithets. For example:<br />
Acacia adunca would be<strong>co</strong>me Ra<strong>co</strong>sperma aduncum<br />
and users that are not familiar with Latin (which I am<br />
pretty sure includes most users) will be tempted to<br />
‘<strong>co</strong>rrect’ it to Ra<strong>co</strong>sperma adunca (Orchard & Maslin<br />
2003). The use of Vachellia and S<strong>en</strong>egalia necessitate<br />
no g<strong>en</strong>der changes as both are feminine.<br />
The retypification issue of Acacia was a very ev<strong>en</strong>ly<br />
<strong>co</strong>ntested debate and both side pres<strong>en</strong>ted very<br />
<strong>co</strong>nvincing argum<strong>en</strong>ts, but the battle has be<strong>en</strong> fought<br />
and a <strong>co</strong>nclusion has be<strong>en</strong> reached. Whether it was<br />
the best route to follow or not, only time will tell.<br />
43<br />
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CLASSIFICATION AND NOMENCLATURE OF THE GENUS ACACIA<br />
Argum<strong>en</strong>ts for Retypification<br />
• Retypification allows for the <strong>co</strong>nservation of some 72% of Acacia s.l. names. Thus greater<br />
nom<strong>en</strong>clatural stability.<br />
• Because Acacia s.s. <strong>co</strong>ntains many rare and <strong>en</strong>dangered species, it is argued that a change to<br />
Ra<strong>co</strong>sperma would have a severe impact on <strong>co</strong>nservation literature and legislation.<br />
• If Ra<strong>co</strong>sperma is adopted, the g<strong>en</strong>der would change from feminine (Acacia) to neuter<br />
(Ra<strong>co</strong>sperma).This will affect the termination of the specific epithet. The use of Vachellia and<br />
S<strong>en</strong>egalia necessitate no g<strong>en</strong>der changes as both are feminine.<br />
• Because about half of Africa’s acacias are changing their names to S<strong>en</strong>egalia anyway, it would be<br />
better and less <strong>co</strong>nfusing if all the naturally occurring acacias just change their names.<br />
• Africa, Asia and the Americas will have to change their floras to ac<strong>co</strong>mmodate S<strong>en</strong>egalia anyway.<br />
• Australian species of Acacia are naturalized in many other parts of the world and will still impact<br />
their floras if it is changed to Ra<strong>co</strong>sperma.<br />
• The official floral emblem of Australia is that of an Acacia s.s.<br />
• Acacia s.s. <strong>co</strong>nstitutes the largest g<strong>en</strong>us of flowering plants on the Australian <strong>co</strong>ntin<strong>en</strong>t.<br />
• E<strong>co</strong>logically significant in Australian e<strong>co</strong>systems.<br />
• More Australian species are of global e<strong>co</strong>nomic importance than African species.<br />
• The Australian group is less likely to be subject to further g<strong>en</strong>eric splitting.<br />
Argum<strong>en</strong>ts against Retypification<br />
• No retypification will restrict the use of the name Acacia to about 12% of Acacia s.l. taxa.<br />
• Retypfication and <strong>co</strong>nservation of g<strong>en</strong>us Acacia to an Australian type will impact many regional<br />
floras around the globe.<br />
• Retypfication and <strong>co</strong>nservation of Acacia will impact a much larger part of the global population,<br />
because Acacia s.s. has a relatively small global distribution wh<strong>en</strong> <strong>co</strong>mpared to Vachellia.<br />
• Many species of Acacia s.s are narrow <strong>en</strong>demics and changing the names of narrow <strong>en</strong>demics has<br />
a much smaller impact than changing the names of species with wide distributions.<br />
• Retypification will b<strong>en</strong>efit ca 20 million people in one <strong>co</strong>untry at the exp<strong>en</strong>se of over a billion<br />
people in about 90 <strong>co</strong>untries.<br />
• Australian acacias are more <strong>co</strong>mmonly known as “wattles” and many will not <strong>co</strong>nnect it with<br />
Acacia. Acacia, however, is used throughout Africa and Latin America as a <strong>co</strong>mmon name.<br />
• Many developing <strong>co</strong>untries will be affected by the retypification, while it only b<strong>en</strong>efits one<br />
developed <strong>co</strong>untry.<br />
• Retypification increases the already big e<strong>co</strong>nomic burd<strong>en</strong> of related name changes placed on<br />
many developing <strong>co</strong>untries.<br />
• The ICBN’s guidelines for <strong>co</strong>nservation of names will be violated by the retypification. It states<br />
that the principle of priority should prevail wh<strong>en</strong> <strong>co</strong>nservation for one part of the world creates a<br />
disad<strong>van</strong>tageous situation in another part of the world.<br />
• Retypification and <strong>co</strong>nservation undermines the rules and guidelines of the ICBN, the principle of<br />
priority in particular. This sets a bad preced<strong>en</strong>t and erodes the authority of the ICBN.<br />
• New <strong>co</strong>mbinations in Ra<strong>co</strong>sperma have be<strong>en</strong> made for the vast majority of Australian species,<br />
while only four <strong>co</strong>mbinations have be<strong>en</strong> made in Vachellia (data curr<strong>en</strong>t in 2005).<br />
• Public perception of Acacia is that of a flat-topped tree in the African sa<strong>van</strong>nah.<br />
• Most species of Vachellia are keystone species in their e<strong>co</strong>systems.<br />
• Rec<strong>en</strong>t split of Cassia into three g<strong>en</strong>era: No one seems to be unhappy with the application of that<br />
name to the smallest of the three g<strong>en</strong>era.v<br />
TABLE 5.–Summary of the argum<strong>en</strong>t pres<strong>en</strong>ted for and against the retypification of Acacia. Information<br />
<strong>co</strong>mpiled from Orchard & Maslin (2003); Luckow et al. (2005); Brummitt (2004) and Thiele et al. (2011).<br />
Conclusion<br />
The literature of such a large and e<strong>co</strong>logically<br />
dominant g<strong>en</strong>us such as Acacia s.l. is <strong>en</strong>ormous and<br />
any changes of nom<strong>en</strong>clature, be it to Vachellia or<br />
Ra<strong>co</strong>sperma, is sure to have profound repercussions.<br />
It will probably take several g<strong>en</strong>erations for the new<br />
classification to be widely used and who knows if it will<br />
still be <strong>co</strong>nsidered curr<strong>en</strong>t at that time. It is <strong>co</strong>mforting<br />
to know, however, that the ICBN does not prescribe<br />
which classification system to use—that choice lies<br />
Refer<strong>en</strong>ces<br />
BENTHAM, G. 1875. Revision of the suborder Mimoseae.<br />
Transactions of the Linnaean Society 30: 444–533.<br />
BOUCHENAK-KHELLADI, Y., MAURIN, O., HURTER, J. & VAN DER<br />
BANK, M. 2010. The evolutionary history and biogeography of<br />
Mimosoideae (Leguminosae): An emphasis on African acacias.<br />
Molecular Phylog<strong>en</strong>etics and Evolution 57: 495–508.<br />
BRITTON, N.L. & BROWN, A. 1913. An illustrated flora of the<br />
northern United States, Canada and the British possessions, vol.<br />
2. Scribner’s, New York.<br />
BRUMMIT, R.K. 2004. Report of the <strong>co</strong>mmittee for<br />
Spermatophyta: 55. Proposal 1584 on Acacia. Taxon 53: 826–829.<br />
CHOI, B.H. & OHASHI, H. 1998. (1377) Proposal to <strong>co</strong>nserve<br />
the name Hedysarum (Leguminosae: Papilioniodeae) with a<br />
<strong>co</strong>nserved type. Taxon 47: 877.<br />
GREUTER, W., WAGENITZ, G., AGABABIAN, M. & HELLWIG,<br />
F.H. 2001. (1509) Proposal to <strong>co</strong>nserve the name C<strong>en</strong>taurea<br />
(Compositae) with a <strong>co</strong>nserved type. Taxon 50: 1201–1205.<br />
HUGHES, C. 1997. (1297) Proposal to <strong>co</strong>nserve the name<br />
Leuceana (Leguminosae) with a <strong>co</strong>nserved type. Taxon 46:<br />
355–356.<br />
KERGOAT, G.J., SILVIAN, J., BURANAPANICHPAN, S. & TUDA, M.<br />
2006. Wh<strong>en</strong> insects help to resolve plant phylog<strong>en</strong>y: evid<strong>en</strong>ce<br />
for paraphyletic g<strong>en</strong>us Acacia from the systematics and<br />
host-plant range of their seed predators. Zoologica Scripta 36:<br />
143–152.<br />
LAWRENCE, E. (Ed.) 2005. H<strong>en</strong>derson’s dictionary of biology,<br />
edn 13. Pearson education Ltd, Essex.<br />
LUCKOW, M., HUGHES, C., SCHRIRE, B., WINTER, P., FAGG,<br />
C.,FORTUNATO, R., HURTER, J., RICO, L., BRETELER, F.J.,<br />
BRUNEAU, A., CACCAVARI, M., CRAVEN, L., CRISP,<br />
M., DELGADO, A., DEMISSEW, S., DOYLE, J.J., GRETHER, R.,<br />
HARRIS, S., HERENDEEN, P.S., HERNANDEZ, H.M., HIRSCH,<br />
A.M., JOBSON, R., KLITGAARD, B.B., LABAT, J., LOCK, M.,<br />
MACKINDER, B., PFEIL, B., SIMPSON, B.B., SMITH, G.F.,SOUSA,<br />
M., TIMBERLAKE, J., VAN DER MAESEN, J.G., VAN WYK, A.E.,<br />
CLASSIFICATION AND NOMENCLATURE OF THE GENUS ACACIA<br />
review<br />
review<br />
with the <strong>en</strong>d users of plant names and they now have<br />
the opportunity to choose whether they want to use<br />
the name Acacia in the strict or broad s<strong>en</strong>se (Smith et<br />
al. 2006). I will <strong>co</strong>nclude this review (which has only<br />
but scratched the surface) on the classification and<br />
nom<strong>en</strong>clature of the g<strong>en</strong>us Acacia s.l. with the following<br />
ironic thought: After retypification, a group of plants<br />
that do not have promin<strong>en</strong>t thorns or spikes now lay<br />
claim to the exclusive use of the name Acacia, derived<br />
from the Greek word Akis, meaning sharp point.<br />
VORSTER, P., WILLIS, C.K., WIERINGA, J.J. & WOJCIECHOWSKI,<br />
M.F. 2005. Acacia: The case against moving the type to Australia.<br />
Taxon 54: 513–519.<br />
MASLIN, B.R., MILLER, J.T. & SEIGLER, D.S. 2003. Overview of<br />
the g<strong>en</strong>eric status of Acacia (Leguminosae: Mimosoideae).<br />
Australian Systematic Botany 16: 1–18.<br />
MCNEILL, J., REDHEAD, S.A. & WIERSEMA, J.H. 2003. Guidelines<br />
for proposals to <strong>co</strong>nserve or reject names. Taxon 52: 182–184.<br />
MILLER, P. 1754. The Gard<strong>en</strong>er’s Dictionary, abridged edn. 4.<br />
London.<br />
ORCHARD, A.E. & MASLIN, B.R. 2003. (1584)Proposal to<br />
<strong>co</strong>nserve the name Acacia (Leguminosae: Mimosoideae) with a<br />
<strong>co</strong>nserved type. Taxon 52: 362–363.<br />
ORCHARD, A.E. & MASLIN, B.R. 2005. The case for <strong>co</strong>nserving<br />
Acacia with a new type. Taxon 54: 509–512.<br />
PEDLEY, L. 1986. Derivation and dispersal of Acacia<br />
(Leguminosae), with particular refer<strong>en</strong>ce to Australia and the<br />
re<strong>co</strong>gnition of S<strong>en</strong>egalia and Ra<strong>co</strong>sperma. Botanical journal of<br />
the Linnaean Society 92: 219–254.<br />
ROSS, J.H. 1979. A <strong>co</strong>nspectus of the African Acacia species.<br />
Memoirs of the botanical exploration of South Africa, no 40.<br />
Botanical Research Institute.<br />
ROSS, J.H. 2004. (1649) Proposal to <strong>co</strong>nserve the name Bossiea<br />
against Platylobium (Leguminosae). Taxon 53: 1075–1076.<br />
SIMPSON, M.G. 2006. Plant Systematics. Elsevier academic<br />
press, San Diego.<br />
SMITH, G.F., VAN WYK, A.E, LUCKOW, M. & SCHRIRE, B. 2006.<br />
Conserving Acacia Mill. with a <strong>co</strong>nserved type. What happ<strong>en</strong>ed<br />
in Vi<strong>en</strong>na? Taxon 55: 223–225.<br />
THIELE, K.R., FUNK, V.A., IWATSUKI, K., MORAT, P., PENG, C.,<br />
RAVEN, P.H., SARUKHAN, J. & SEBERG, O. 2011. The <strong>co</strong>ntroversy<br />
over the retypification of Acacia Mill. with an<br />
Australian type: A pragmatic view. Taxon 60: 194–198.<br />
VASSAL, J. 1981. Acacieae. In R.M. Polhill & P.H. Rav<strong>en</strong>, Ad<strong>van</strong>ces<br />
in Legume Systematics, part 1. Kew Royal Botanic Gard<strong>en</strong>s.<br />
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review<br />
UNDERGROUND TREES OF THE PONDOLAND CENTRE<br />
Underground trees of the Pondoland C<strong>en</strong>tre<br />
The term ‘underground trees’ evocatively<br />
pres<strong>en</strong>ts a picture in one’s mind, perhaps of<br />
a baobab buried deep in the ground, with just its<br />
branch tips showing above the surface. Well now,<br />
this is not quite how it is, but the <strong>co</strong>ncept is pretty<br />
close. First the history, and there is not too much of<br />
that. In 1922, Joseph Burtt Davy [1870–1940] wrote<br />
a paper <strong>en</strong>titled ‘The suffrutesc<strong>en</strong>t habit as an<br />
adaptation to <strong>en</strong>vironm<strong>en</strong>t’. Burtt Davy was quite a<br />
remarkable fellow; he was born in England, worked<br />
at Kew and later in California, having by th<strong>en</strong> stu<strong>die</strong>d<br />
both botany and agriculture. In 1903 he joined the<br />
Transvaal Departm<strong>en</strong>t of Agriculture and in 1925,<br />
finally w<strong>en</strong>t as a lecturer at the Imperial Forestry<br />
Institute, Oxford. This twofold academic training<br />
together with his experi<strong>en</strong>ces in differ<strong>en</strong>t parts of<br />
the world gave him a solid feel for plant e<strong>co</strong>logy.<br />
In his paper Burtt Davy pres<strong>en</strong>ts some possible<br />
reasons for the evolution of what are now called<br />
geoxylic suffrutices (singular: geoxylic suffrutex) or<br />
“geosuffs”, a term <strong>co</strong>ined by Marita Thornhill and<br />
Ian Felton in their article in PlantLife No. 23. The<br />
term ‘geofrutex’ is also occasionally <strong>en</strong><strong>co</strong>untered as<br />
a synonym in the literature but I prefer geosuff.<br />
Ac<strong>co</strong>rding to the refer<strong>en</strong>ces I have, definitions of<br />
suffrutex and geoxylic are: an undershrub (Jackson<br />
1971): half shrub, sub-shrub, per<strong>en</strong>nial plant with<br />
only the lower part woody (Stearn 1983). The only<br />
refer<strong>en</strong>ce to “geoxyl” says: having a woody stem,<br />
partly hypogeic (growing on or remaining below<br />
ground), partly epigeic (spreading above the<br />
surface (Jackson 1971).<br />
Frank White [1927–1994], Curator of the Forest<br />
tony abbott<br />
Herbarium and Lecturer in Systematic Forest<br />
Botany at Oxford University, held a lifelong interest<br />
in the woody plants of southern Africa and was<br />
r<strong>en</strong>owned for his knowledge and work on the<br />
vegetation of sub-Saharan Africa. White was the<br />
next to look in more detail at this ph<strong>en</strong>om<strong>en</strong>on and<br />
in 1976 published his now classic paper on the<br />
‘Underground Forests of Africa’. Here he suggests<br />
that in many African grasslands, in particular those<br />
of shallow wetlands and floodplains (‘dambos’) in<br />
south-c<strong>en</strong>tral Africa, the underground biomass of<br />
‘underground trees’ exceeds that of the associated<br />
grasses. He describes these peculiar ‘trees’ as<br />
having massive woody underground parts….In the<br />
majority, several axes radiate just b<strong>en</strong>eath the surface<br />
of the soil from the main vertical subterranean axis,<br />
which, except in young plants, is relatively poorly<br />
developed. Sometimes they ext<strong>en</strong>d for a distance of<br />
several metres. In some species these axes can reach<br />
a diameter of 10 cm. or more. They are usually very<br />
hard and <strong>co</strong>nsist mostly of se<strong>co</strong>ndary xylem, the total<br />
amount of which is probably no less than that of a<br />
medium-sized woodland tree growing in the same<br />
g<strong>en</strong>eral region. These radiating axes are usually<br />
referred to as rhizomes. Their true nature, however,<br />
requires careful investigation since the arboreal<br />
relatives of some suffrutices are said to sucker freely<br />
from their ext<strong>en</strong>sive superficial roots.<br />
Here is what Prof. Braam <strong>van</strong> Wyk had the following<br />
to say in an address at a <strong>co</strong>nfer<strong>en</strong>ce in Nelspruit on<br />
the 13th November 2003 regarding the impact of<br />
timber plantations on grasslands (transcript at www.<br />
geasphere.<strong>co</strong>.<strong>za</strong>; accessed 24 April 2008):<br />
Pyrog<strong>en</strong>ic geoxylic suffrutices is a very peculiar growth form that is associated with our grasslands,<br />
and it is very much a type of growth form in Africa. It is not found anywhere else in the world except<br />
perhaps to a limited degree in South America. It is a growth form where you get plants, woody<br />
plants that can be <strong>co</strong>mpared to underground trees, and all that you see are these gre<strong>en</strong> twigs<br />
which can be <strong>co</strong>mpared with a canopy of the tree. And this is probably one plant sitting here, or<br />
maybe ev<strong>en</strong> this whole area may be one plant, and it’s the canopy that just sticks out, the tips of the<br />
branches above ground. They burn down every year, but the rest of the tree stays underground.<br />
Why they have adopted this strategy… it is a very interesting chall<strong>en</strong>ge to <strong>co</strong>me up with reasons.<br />
Is it fire? We don’t think so. Is some of it frost? Shallow water table? Grazing? There are lots of interesting<br />
things we can say about the reasons why it adopted this strategy and why it only evolved in Africa.<br />
Now these clones, because we call them clones, they are ess<strong>en</strong>tially immortal, nothing can kill them.<br />
Grazers can not kill them, fire can not kill them, they are drought resistant. They grow extremely<br />
A geosuff is described by Yolande Ste<strong>en</strong>kamp<br />
and <strong>co</strong>-authors in PlantLife No. 25 as ‘basically<br />
an underground tree, with a massive, woody,<br />
underground, per<strong>en</strong>nial c<strong>en</strong>tral axis (oft<strong>en</strong> called a<br />
rhizome) and many short-lived (annual) shoots above<br />
ground’. In Burtt Davy’s paper he shows a drawing of<br />
Parinarium cap<strong>en</strong>se. (now Parinari cap<strong>en</strong>sis. subsp.<br />
cap<strong>en</strong>sis) with a huge stem driving down into the<br />
depths. Today, however, it is <strong>co</strong>nsidered that while<br />
the initiating plant may have had a tap root, in most<br />
instances it <strong>die</strong>s off and is superseded by an axillary<br />
network of woody roots and stems (rhizomes) which<br />
reach outwards from the point of origin supporting<br />
aerial outgrowths or ramets (individual members of<br />
a clone); see the picture of Eug<strong>en</strong>ia alban<strong>en</strong>sis (Vlei<br />
myrtle). Considering the description by Ste<strong>en</strong>kamp<br />
and <strong>co</strong>-authors above, we should rather talk of an<br />
ext<strong>en</strong>sive, rather than a massive, underground<br />
network of inter<strong>co</strong>nnected woody axes. For the<br />
pres<strong>en</strong>t article, geosuff should be tak<strong>en</strong> to refer to<br />
a species which is woody in itself and mostly with<br />
close relatives that are proper trees. These can be<br />
divided into ‘facultative’ (wh<strong>en</strong> forced by outside<br />
pressures) and ‘obligate’ (wh<strong>en</strong> <strong>co</strong>mpelled by<br />
g<strong>en</strong>etic requirem<strong>en</strong>t) geosuffs and here we <strong>en</strong>ter<br />
a rather grey area with the occasional doubt in<br />
deciding what falls into which group. In Pondoland<br />
we have, for example, two species which occur<br />
as trees and also as possible facultative geosuffs,<br />
namely Diospyros scabrida (Coastal bladdernut)<br />
and Ochna natalitia (Natal plane). At pres<strong>en</strong>t we<br />
assume that the same species may display both life<br />
forms, but future taxonomic investigation, especially<br />
at g<strong>en</strong>e level, might change this. Eug<strong>en</strong>ia cap<strong>en</strong>sis<br />
subsp. cap<strong>en</strong>sis (Dune myrtle) grows as a shrub or<br />
small tree in dune forests but can occur as a geosuff<br />
along forest fringes, especially wh<strong>en</strong> subjected to<br />
frequ<strong>en</strong>t grassland fires.<br />
We excavated part of an ext<strong>en</strong>sive stand of Eug<strong>en</strong>ia<br />
alban<strong>en</strong>sis (Vlei myrtle), an obligate geosuff,<br />
growing in red sands of the Berea Formation—a<br />
system of anci<strong>en</strong>t <strong>co</strong>astal dune <strong>co</strong>rdons inland<br />
from our pres<strong>en</strong>t <strong>co</strong>astline. After exposing an area<br />
about 3 m long, the growth pattern appeared to<br />
be quite random with narrow (10–20 mm thick)<br />
rhizomes running in all directions about 20 to 50<br />
cm below ground level; we did not see any sign of<br />
a root dropping vertically into the depths. It seems<br />
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slowly, and if you look at the diameter of some of these clones, they must be the oldest inhabitants<br />
of our grasslands. I would say easily more than a thousand years for many of these clones since the<br />
first seed arrived for that particular species. But I would not be surprised if some of them are one<br />
day shown to be perhaps more than 10 000 years old, amongst the oldest plants in the world, much<br />
older than any tree that you are going to see. They are very peculiar plants and we have quite a<br />
number of these species in our grasslands.<br />
probable that the clone exists as a self-reg<strong>en</strong>erating<br />
organism where the rhizomes most likely have a<br />
limited life (perhaps of some years) and are replaced<br />
from time to time. I got the real impression that the<br />
aerial shoots scattered over a large area (about a<br />
hectare) <strong>co</strong>uld well prove to be inter<strong>co</strong>nnected—if<br />
one <strong>co</strong>uld only have X-ray vision. Like the Eug<strong>en</strong>ia<br />
cap<strong>en</strong>sis subsp. gueinzii (Coast myrtle) m<strong>en</strong>tioned<br />
below, these clonal <strong>co</strong>lonies must take at least<br />
hundreds of years to establish over such large areas.<br />
Herbaceous clones of non-grassy herbs (‘wild<br />
flowers’) are quite <strong>co</strong>mmon in fire-prone grassland<br />
and are provided by several families, including<br />
Asteraceae (Helichrysum), Euphorbiaceae<br />
(Acalypha), Fabaceae (Eriosema, Indigofera),<br />
Lamiaceae (Becium) and Rubiaceae (P<strong>en</strong>tanisia). The<br />
Pondoland C<strong>en</strong>tre <strong>en</strong>demic, Helichrysum pannosum<br />
(Pondo everlasting), forms large clones several<br />
metres across. A species such as Eriosemopsis<br />
subanisophylla (Mock eriosema), however, seems to<br />
qualify as a true geosuff, the heavy woody rootstock<br />
of this plant and multiple shoots (note that in the<br />
picture of this plant most of the aerial shoots had<br />
be<strong>en</strong> brok<strong>en</strong> off during the excavation due to the<br />
very brittle nature of the species) have a woody<br />
appearance, but the species has no true arboresc<strong>en</strong>t<br />
relatives as it is the only member of the g<strong>en</strong>us. It<br />
is nevertheless closely related to other groups of<br />
woody Rubiaceae that include many proper trees.<br />
The pot<strong>en</strong>tial reasons put forward by the various<br />
authors to explain the evolution of geosuffs from<br />
arboresc<strong>en</strong>t ancestors are several and these<br />
include: extreme <strong>co</strong>ld, aridity, water logging,<br />
edaphic <strong>co</strong>nstraints, herbivory, fire and soil fertility<br />
(or lack thereof). Burtt Davy points out that a tree<br />
<strong>co</strong>uld not invade grassland and th<strong>en</strong> evolve a<br />
suffrutesc<strong>en</strong>t habit. The e<strong>co</strong>tones of forest margins,<br />
however, are dynamic habitats with adv<strong>en</strong>turous<br />
woody plants attempting to push out from the forest<br />
into the grassland. Could these e<strong>co</strong>tones pres<strong>en</strong>t<br />
an opportunity for the evolution of geosuffs? A<br />
walk in spring along our forest margins reveals<br />
several otherwise arboresc<strong>en</strong>t species putting out<br />
shoots in the e<strong>co</strong>tone, the <strong>en</strong>demic Rhynchocalyx<br />
lawsonioides (Mock umdoni) being one of them. The<br />
two species m<strong>en</strong>tioned earlier, Diospyros scabrida<br />
(Coastal bladdernut) and Ochna natal<strong>en</strong>sis (Natal<br />
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plane), occur widely as forest trees but also can be<br />
found as chasmophytes (growing in fire-protected<br />
rock crevices) in and around rock exposures in<br />
the grasslands, oft<strong>en</strong> near forests. Under these<br />
<strong>co</strong>nditions, the aerial parts are burnt off regularly,<br />
but I have not se<strong>en</strong> an indication of reversion to the<br />
arboresc<strong>en</strong>t state in places where fire has missed<br />
out a year or two. It would be informative to study<br />
the g<strong>en</strong>etics of the two forms of these species to see<br />
whether they are either facultative geosuffs or, just<br />
possibly, evolving towards the obligate state. The<br />
other possibility would be to take seed of each form<br />
for growing on, but as the transition from one form<br />
to the other may be in<strong>co</strong>mplete, seeds <strong>co</strong>uld also<br />
be in a stage of transition and reproduce either way.<br />
The age of plants has always be<strong>en</strong><br />
a fascination...it is be<strong>co</strong>ming clear<br />
the we have a t<strong>en</strong>c<strong>en</strong>cy to seriously<br />
underestimate it.<br />
Looking at the occurr<strong>en</strong>ce of geosuffs in the<br />
Pondoland C<strong>en</strong>tre, temperatures are moderate;<br />
dry periods, especially in winter, can occur but<br />
droughts are rare; geosuffs occur on both the<br />
shallower sandstone derived soil of the Msikaba<br />
Formation and on deeper dune sands; herbivory is<br />
a <strong>co</strong>nstant; fire is also a <strong>co</strong>nstant in our grasslands<br />
(Abbott, PlantLife 35) and the soils are nutri<strong>en</strong>t poor<br />
because of the high rainfall.<br />
Meg Coates Palgrave (PlantLife 18) is <strong>co</strong>nvinced<br />
that the success of seedlings in the indig<strong>en</strong>ous<br />
woodlands (‘miombos’) of Zimbabwe is an<br />
infrequ<strong>en</strong>t occurr<strong>en</strong>ce and suggests that there,<br />
trees normally reproduce vegetatively from<br />
existing rootstocks. This provides an example of the<br />
ancestral ability of woody plants to produce <strong>co</strong>ppice<br />
shoots but still leaves the reasons for adopting the<br />
geosuff growth form (as opposed to a proper tree)<br />
unexplained. In <strong>co</strong>ntrast to Meg’s findings in the<br />
Zimbabwe woodlands, our forest species down here<br />
seem to do quite well in setting seed and g<strong>en</strong>erating<br />
seedlings although some species certainly flower<br />
irregularly. Ev<strong>en</strong> <strong>co</strong>ppicing forest species such as<br />
Dahlgr<strong>en</strong>od<strong>en</strong>dron natal<strong>en</strong>se (Sandstone quince)<br />
set fertile seed from time to time. Another such tree<br />
is the rare Lyd<strong>en</strong>burgia abbottii (Pondo bushmans<br />
tea) which I have se<strong>en</strong> with a mass of seedlings<br />
below it.<br />
Compared to our forest reg<strong>en</strong>eration, Pondoland<br />
grasslands appear to dep<strong>en</strong>d largely on per<strong>en</strong>nial<br />
species which shoot at ground level or below, socalled<br />
resprouters. The number of herbaceous plant<br />
species which exist as clones is large and as A<strong>co</strong>cks<br />
(1975) tells us “The Pondoland Plateau Sourveld<br />
is the d<strong>en</strong>sest veld in the Republic, so d<strong>en</strong>se that<br />
grasses grow as single shoots rather than as tufts;<br />
at least the tufts are very small.” Thus it seems likely<br />
that seedlings would find it harder to establish<br />
amongst resprouters and tufted species.<br />
The range of selective pressures suggested to<br />
promote the geosuff growth form is quite large,<br />
but the wide range of distribution and <strong>co</strong>nditions<br />
of geosuff occurr<strong>en</strong>ce suggests to me that the<br />
pressures of fire and herbivory are indeed<br />
candidates for such a change of behaviour, at least<br />
in the Pondoland C<strong>en</strong>tre. These <strong>co</strong>uld well be acting<br />
in <strong>co</strong>ncert with some or all of the other factors put<br />
forward. Here, I would suggest the opportunity<br />
offered by forest margin e<strong>co</strong>tones with grassland<br />
<strong>co</strong>uld well be a pot<strong>en</strong>tial nursery school for the<br />
evolution of geoxylic suffrutices from arboresc<strong>en</strong>t<br />
forest forms.<br />
The age of plants has always be<strong>en</strong> a fascination to me<br />
and it is be<strong>co</strong>ming clear that we have had a t<strong>en</strong>d<strong>en</strong>cy<br />
to seriously underestimate it. Ac<strong>co</strong>rding to a popular<br />
website that, amongst others provides information<br />
on botanical re<strong>co</strong>rd breakers (waynesword.<br />
palomar.edu accessed 14 April 2008) there is a<br />
shrub in the Mojave Desert called creosote bush,<br />
Larrea trid<strong>en</strong>tata (Zygophyllaceae). The original<br />
stem produces a series of aerial branches but as the<br />
c<strong>en</strong>tre of the stem <strong>die</strong>s off, the remaining portions<br />
<strong>co</strong>ntinue to grow as a large ring of peripheral shoots;<br />
a growth pattern reminisc<strong>en</strong>t of that in a geosuff,<br />
except that in the case of creosote bush the clone<br />
forms an ever-wid<strong>en</strong>ing circle surrounding a c<strong>en</strong>tral<br />
barr<strong>en</strong> area. The oldest of these clones is estimated<br />
to be about 12 000 years old. Another clonal plant,<br />
Lomatia tasmanica (Proteaceae) in Tasmania, may<br />
be one of the oldest plant clones in the world. Known<br />
as the King’s Holly, the species appears to be a<br />
sterile triploid incapable of producing viable seeds<br />
and the existing clones are estimated to be as much<br />
as 43 000 years old! With examples such as these,<br />
we should not be shy to suggest <strong>co</strong>nsiderable ages<br />
for our geosuffs. There is an ext<strong>en</strong>sive clonal <strong>co</strong>lony<br />
of Eug<strong>en</strong>ia cap<strong>en</strong>sis subsp. gueinzii (Coast myrtle)<br />
in grassland on the anci<strong>en</strong>t Berea Formation sand<br />
dunes along the Wild Coast which is about 50 x 30<br />
m in ext<strong>en</strong>t. No doubt this particular clone must be<br />
many hundreds, if not thousands of years old. This<br />
evid<strong>en</strong>ce of long term stability is a very important<br />
<strong>co</strong>nsideration wh<strong>en</strong> developm<strong>en</strong>ts are proposed<br />
which can destroy our grasslands. In fact, this<br />
particular <strong>co</strong>lony of Eug<strong>en</strong>ia capesis subsp. gueinzii<br />
(Coast myrtle) grows on dunes earmarked for the<br />
possible mining of heavy minerals. Suggestions<br />
of rehabilitation or revegetation, oft<strong>en</strong> m<strong>en</strong>tioned<br />
in <strong>en</strong>vironm<strong>en</strong>tal assessm<strong>en</strong>ts, seem rather<br />
presumptuous. It is quite clear that the prefix “re-”<br />
is out of place and all that can happ<strong>en</strong> to grassland<br />
which has be<strong>en</strong> destroyed by developm<strong>en</strong>t, is the<br />
introduction of plants to provide a <strong>co</strong>vering to the soil<br />
without a hope of restoring the earlier e<strong>co</strong>system.<br />
Anisha Dayaram of Wits University is curr<strong>en</strong>tly<br />
working on carbon dating some geosuffs in<br />
<strong>co</strong>llaboration with Custodians of Rare and<br />
Endangered Wildflowers (CREW). There is so little<br />
known about the underground parts of plants in<br />
grasslands and I am delighted that Anisha has tak<strong>en</strong><br />
on this project and I sincerely hope that it will lead<br />
to other investigations into the behaviour of more of<br />
these plants.<br />
Marita Thornhill and Ian Felton (PlantLife 23) feel<br />
that the term “woody grasslands” better describes<br />
the <strong>co</strong>astal grasslands of Maputaland with their<br />
abundant of geosuffs. Perhaps we should give<br />
thought to changing our terminology for the<br />
Pondoland veld to give re<strong>co</strong>gnition to the fact that,<br />
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although individual numbers of grasses exceed all<br />
other kinds of plant in our ‘grasslands’, they are far<br />
the least in species numbers and biomass. Cryptic<br />
Sa<strong>van</strong>na or Dwarf Op<strong>en</strong> Woodland perhaps, but<br />
certainly something which gives better re<strong>co</strong>gnition<br />
to the plant assemblage.<br />
Refer<strong>en</strong>ces:<br />
1. Abbott, A.T.D. 2006. Where do our beautiful<br />
2.<br />
grasslands <strong>co</strong>me from? PlantLife 35: 3–6.<br />
Burtt Davy, J. 1922. The suffrutesc<strong>en</strong>t habit as an adaptation<br />
to <strong>en</strong>vironm<strong>en</strong>t. Journal of E<strong>co</strong>logy 10: 211–219.<br />
3. A<strong>co</strong>cks, J.P.H., 1975. Veld types of South Africa. Botanical<br />
Research Institute, Pretoria.<br />
4. Coates Palgrave, M. 1988. Reg<strong>en</strong>eration of indig<strong>en</strong>ous<br />
woodland in Zimbabwe. PlantLife 18: 30–32.<br />
5. Gunn, M. & Codd, L.E. 1981. Botanical exploration of<br />
southern Africa. B.R.I. A.A.Balkema, Cape Town.<br />
6. Jackson, B. Daydon, 1971. A glossary of botanic terms.<br />
Hafner Publishing, New York.<br />
7. Thornhill, M. & Felton, I. 2000. The underground forests of<br />
Maputaland. PlantLife 23: 9–10.<br />
8. Stearn, W., 1983. Botanical Latin. David & Charles, London.<br />
9. Ste<strong>en</strong>kamp, Y., Kellerman, M.J.S. & Van Wyk, A.E. 2001. Fire,<br />
frost, waterlogged soil or something else: what selected for<br />
the geoxylic suffrutex growth form in Africa? PlantLife 25: 4–6.<br />
10. White, F. 1976. The underground forests of Africa: a<br />
preliminary review. Gard<strong>en</strong>s’ Bulletin, Singapore 29: 55–71.<br />
Virtual Tree Herbarium (ViTH)<br />
Adapted from news items distributed by the University of Johannesburg & Naas Grové<br />
The University of Johannesburg, under the auspices<br />
of Prof Michelle <strong>van</strong> der Bank and Dr. Oliver Maurin,<br />
is busy developing a Virtual Tree Herbarium (ViTH)<br />
based on the same <strong>co</strong>ncept as similar projects for<br />
birds, mammals and other organisms with the Bird<br />
Atlas and Virtual Museum. The g<strong>en</strong>eral idea is to have<br />
a system available to anyone, to capture tree / shrub<br />
observations from the field. This idea appealed to<br />
the C<strong>en</strong>tral Committee of the D<strong>en</strong>drological Society<br />
as it has prov<strong>en</strong> to be very successful with projects<br />
such as the Bird Atlas. It is a non-profit initiative<br />
that would allow our members from all branches<br />
to <strong>co</strong>ntribute towards the developm<strong>en</strong>t of more<br />
accurate species distributions maps, and thus<br />
<strong>co</strong>ntribute towards sci<strong>en</strong>ce.<br />
The data that would be uploaded by the members<br />
of the Society on the system will only involve<br />
observations and must <strong>co</strong>ntain: 1) A Temporary<br />
id<strong>en</strong>tification 2)A GPS location and 3) A set of<br />
photographs of the tree, leaves, bark and any other<br />
features such as fruit and flowers (to help <strong>co</strong>nfirm<br />
the id<strong>en</strong>tification).<br />
A panel of experts th<strong>en</strong> has to scre<strong>en</strong>, evaluate and<br />
verify all submissions at intervals and re<strong>co</strong>rd those<br />
which can be verified. The verified data would<br />
ev<strong>en</strong>tually serve as the basis for an accurate map<br />
and database of tree / shrub species found in all<br />
parts of the <strong>co</strong>untry.<br />
The D<strong>en</strong>drological Society held a workshop<br />
facilitated by Dr. Oliver Maurin and Professor<br />
Michelle <strong>van</strong> der Bank on 30 July 2011 at the<br />
University of Johannesburg to discuss the project<br />
and ways to participate. The following members<br />
att<strong>en</strong>ded the workshop: Gert Middelberg, Fanie de<br />
Meillon, I<strong>za</strong>k <strong>van</strong> der Merwe, Naas Grové, Christoph<br />
Fuhrmann and Walter Barker (Tree Society of South<br />
Africa)<br />
An experim<strong>en</strong>tal survey of 33 tree species was<br />
made in Melville Koppies on 15 October 2011 by<br />
the Magalies branch of the Society during an outing<br />
with the botany Masters Stud<strong>en</strong>t Mr Phillip Rousseau<br />
of the University of Johannesburg, and these were<br />
the first <strong>en</strong>tries to be submitted by the Society on the<br />
ViTH system. Members who wish to <strong>co</strong>ntribute to the<br />
project can <strong>co</strong>nsult our website for more information<br />
at www.d<strong>en</strong>dro.<strong>co</strong>.<strong>za</strong><br />
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TSATE HERITAGE SITE IN SEKHUKHUNELAND<br />
REUSE VORM VAN XEroPHytA rEtInErVIS – BOBBEjAANSTERT » Foto Naas Grové<br />
The Tsate Heritage Site in Sekhukhuneland<br />
On our way to visit Tsate on 4-6 February 2011,<br />
I tried to imagine how the area would look like<br />
and how <strong>co</strong>uld I <strong>co</strong>ntribute to a successful out<strong>co</strong>me.<br />
In all my years of botanizing I always managed to<br />
by-pass the area and <strong>co</strong>nsoling myself with the<br />
promise of one day…!!<br />
That day had <strong>co</strong>me, and it <strong>co</strong>uldn’t have be<strong>en</strong> with a<br />
more fri<strong>en</strong>dly and knowledgeable group of people<br />
that I was privileged to be with that week<strong>en</strong>d. I also<br />
came to realize that every-one of the participants<br />
had something unique to add to the total of the<br />
experi<strong>en</strong>ce.<br />
I fully agree with what has be<strong>en</strong> writt<strong>en</strong> by other<br />
members and therefore I will not duplicate<br />
unnecessarily. I will also <strong>co</strong>nc<strong>en</strong>trate more on<br />
the issues raised by Li<strong>za</strong>nne Nel regarding the<br />
feasibility of a sustainable and profitable project for<br />
the Tsate <strong>co</strong>mmunity. These are only my personal<br />
thoughts which I offer, regardless of the possibility<br />
of “carrying <strong>co</strong>al to Newcastle”<br />
Basic strategic thoughts<br />
These thoughts are put down randomly as they<br />
<strong>co</strong>me to mind:<br />
• The Sekhukhuneland C<strong>en</strong>tre of Plant Endemism<br />
boasts 58 <strong>en</strong>demic, 70 near-<strong>en</strong>demics and 46<br />
threat<strong>en</strong>ed plant species. How many did we see<br />
during the 2 days? It will indeed be a chall<strong>en</strong>ge<br />
to be able to show the visitor every single one of<br />
them. Why not cultivate them and plant them in<br />
their respective habitats along a special route?<br />
Th<strong>en</strong> one can advertise! Think of a f<strong>en</strong>ced-off,<br />
dedicated Botanical Reserve and include the<br />
NBI and other Departm<strong>en</strong>ts of the Governm<strong>en</strong>t<br />
in the planning and execution of such a project.<br />
This idea might spread to the other c<strong>en</strong>ters of<br />
plant <strong>en</strong>demism<br />
• A “Heritage site” is developed and administered,<br />
and its natural and cultural resources protected,<br />
advertised and shown with pride to visitors. It is<br />
not there to be used up for wood or grazing by<br />
the local <strong>co</strong>mmunity.<br />
• Special att<strong>en</strong>tion should be giv<strong>en</strong> to the<br />
eradication of all ali<strong>en</strong> and weed species.<br />
• People who <strong>co</strong>me for camping are usually<br />
discerning nature lovers. Well situated,<br />
secluded from the local <strong>co</strong>mmunity and<br />
serviced camping sites is a must. High class,<br />
serviced ablution facilities indicate to the visitor<br />
Hans Vahrmeijer<br />
TSATE HERITAGE SITE IN SEKHUKHUNELAND<br />
review<br />
review<br />
your attitude towards them. Mediocre facilities<br />
t<strong>en</strong>d to be <strong>van</strong>dalized very quickly.<br />
• The Heritage site is a cultural- historic site for<br />
the Bapedi people, and it should be the Bapedi<br />
who must be the main “marketing focus”. This<br />
means that the site must be <strong>en</strong>riched in such<br />
a way that the visitor can experi<strong>en</strong>ce a full or<br />
‘<strong>co</strong>mplete’ Pedi cultural experi<strong>en</strong>ce. A good<br />
developm<strong>en</strong>t av<strong>en</strong>ue will be the in<strong>co</strong>rporation<br />
of this cultural experi<strong>en</strong>ce (visit to Tsate) in<br />
the formal curriculum of at least the schools<br />
serving the Bapedi people.<br />
• One of the most underrated attractions is<br />
certainly the “Musical Rocks”. I don’t know their<br />
history, or ev<strong>en</strong> if the Bapedi used them. Judging<br />
by the wear on the rocks they must have played<br />
a c<strong>en</strong>tral role in some cultural activity for many,<br />
many years. An in-depth study should be done<br />
on them by professional sci<strong>en</strong>tists and the rocks<br />
should <strong>en</strong>joy special protection. If some of the<br />
older Pedi still know how to play them, or some<br />
can teach themselves to do it, it will be a unique<br />
opportunity to produce “anci<strong>en</strong>t” music such as<br />
can be heard nowhere else in the world. This<br />
can be<strong>co</strong>me a major draw-card for the project.<br />
• The Heritage site can only be sustainable wh<strong>en</strong><br />
it serves the purpose for which it has be<strong>en</strong><br />
established and wh<strong>en</strong> it is also ad<strong>van</strong>tageous to<br />
the <strong>co</strong>mmunity in which it is located.<br />
• With the governm<strong>en</strong>t’s interest, professional<br />
knowledge of the developers, interest of<br />
various professional bo<strong>die</strong>s and organi<strong>za</strong>tions<br />
be<strong>co</strong>ming aware of Tsate, a lot of knowledge,<br />
interest, advice, help, public interest and ev<strong>en</strong><br />
money t<strong>en</strong>d to gravitate towards the project.<br />
These formal and informal resources should be<br />
used to the maximum to achieve the goals.<br />
• In the pres<strong>en</strong>t times, money-driv<strong>en</strong>, successful<br />
profit c<strong>en</strong>ters ‘rules the roost’ and determines<br />
the success or failure of a project like Tsate.<br />
This makes it imperative for Tsate to plan for<br />
such projects.<br />
Possible projects for Tsate<br />
1. Establishing a nursery to legally sell indig<strong>en</strong>ous<br />
plants grown from mother stock in the Endemic<br />
Plant C<strong>en</strong>tre. I am sure Searsia batophylla will be<br />
a horticultural success. I am sure Tsate will be<br />
able to obtain permits to sell rare and <strong>en</strong>dangered<br />
species propagated in their nursery.<br />
2. Planting Dovyalis species like the Kei-apple<br />
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TSATE HERITAGE SITE IN SEKHUKHUNELAND<br />
with its prolific fruits in an orchard, a huge<br />
source of vitamin-rich fruit juice or jam for local<br />
and national markets.<br />
3. Planting medicinal plants in the veld to be<br />
harvested and sold in muthi-markets<br />
4. With the help of the CSIR (ECD) in Pretoria it is<br />
possible to design a project for the production<br />
of aromatic oils suitable for the Tsate area.<br />
5. Planting of a woodlot for the <strong>co</strong>mmunity. The<br />
mines in the area and those at Burgersfort<br />
will most likely have a Trust fund for the<br />
developm<strong>en</strong>t of the <strong>co</strong>mmunities (Social<br />
responsibility fund) which can be <strong>co</strong>ntacted<br />
for participation in the projects.<br />
6. Why not design an overall network in the<br />
<strong>co</strong>untry for all the differ<strong>en</strong>t cultures (Maybe only<br />
the main ones) where especially the overseas<br />
visitors can experi<strong>en</strong>ce cultural <strong>co</strong>ntact.<br />
Cultural Tourism is on the rise as experi<strong>en</strong>ced<br />
in Soweto, Zululand and other areas. These<br />
cultural c<strong>en</strong>ters or Heritage sites can liaise and<br />
network to help and ‘cross-pollinate’ each other.<br />
7. Contact the historical associations, wargrave<br />
<strong>co</strong>mmissions, cultural attaché’s of<br />
the UK and Swaziland to raise interest in<br />
building a memorial for their own people who<br />
participated in the 1879 war.<br />
8. Design a big hall and <strong>en</strong>ough ablution facilities<br />
to ac<strong>co</strong>mmodate big gatherings of the Bapedi,<br />
be it of political, cultural, social or whatever<br />
nature. The facilities can be leased to pay for the<br />
maint<strong>en</strong>ance. The bottom line is—Make Tsate a<br />
cultural c<strong>en</strong>tre for the Bapedi in practice.<br />
I trust that these loose ideas stimulate further<br />
thoughts that will help put Tsate on the tourist maps.<br />
My <strong>co</strong>ntribution to the tree and plant lists of the<br />
Tsate area is depicted in the tables below:<br />
Medicinal plants<br />
Acacia caffra<br />
Acacia karroo<br />
Acacia mellifera subsp. detin<strong>en</strong>s<br />
Acacia nilotica subsp. kraussiana<br />
A<strong>co</strong>kanthera oppositifolia<br />
Acridocarpus natalitius<br />
Albizia anthelmintica<br />
Aloe marlothii<br />
Balanites maughamii<br />
Bauhinia tom<strong>en</strong>tosa<br />
Berchemia zeyheri<br />
Berch<strong>en</strong>ia zeyheri<br />
Bolusanthus speciosus<br />
Boscia foetida subsp. rehmanniana<br />
Brachyla<strong>en</strong>a ilicifolia<br />
Buddleja saligna<br />
Calod<strong>en</strong>drum cap<strong>en</strong>se<br />
Carissa bispinosa subsp. bispinosa<br />
Catha edulis<br />
Catharanthus roseus<br />
Celtis africana<br />
Chaetachme aristata<br />
Cissampelos mucronata<br />
Clematis brechiata<br />
Clerod<strong>en</strong>dron ternatum<br />
Clerod<strong>en</strong>drum glabrum<br />
Combretum apiculatum<br />
Combretum herero<strong>en</strong>se<br />
Combretum imberbe<br />
Combretum molle<br />
Combretum zeyheri<br />
Commelina b<strong>en</strong>ghal<strong>en</strong>se<br />
Croton gratissimus var. gratissimus<br />
Cussonia paniculata<br />
Cyphostemma natalitium<br />
Datura stramonium<br />
Dichrostachys cinerea subsp. africana<br />
Diospyros lycioides subsp. lycioides<br />
Dombeya rotundifolia<br />
Dovyalis caffra<br />
Ehretia amo<strong>en</strong>a<br />
Ehretia rigida<br />
Elaeod<strong>en</strong>dron transvaal<strong>en</strong>se<br />
Elephantorrhi<strong>za</strong> burkei<br />
Euclea crispa<br />
Euphorbia <strong>co</strong>operi<br />
Euphorbia ing<strong>en</strong>s<br />
Euphorbia tirucalli<br />
Evolvulus alsnoides<br />
Flueggea virosa<br />
Gomphocarpus fruti<strong>co</strong>sus<br />
Grewia flavesc<strong>en</strong>s<br />
Gymnosporia buxifolia<br />
Helinus integrifolius<br />
Heliotropium ciliatum<br />
Heteromorpha arboresc<strong>en</strong>s var. abyssinica<br />
Hippobromus pauciflorus<br />
Lantana rugosa<br />
Lippia ja<strong>van</strong>ica<br />
Maerua angol<strong>en</strong>sis<br />
Mimusops zeyheri<br />
Monsonia angustifolia<br />
Mundulea sericea<br />
Myrothamnus flabellifolius<br />
obetia t<strong>en</strong>ax<br />
olea europaea subsp. africana<br />
Pappea cap<strong>en</strong>sis<br />
Pellaea calomelanos<br />
Peltophorum africanum<br />
Phyllanthus parvulus<br />
Polygala virgata var. de<strong>co</strong>ra<br />
Pouzolzia mixta<br />
Psiadia punctulata<br />
Pterocelastrus echinatus<br />
rhoicissus trid<strong>en</strong>tata subsp. cuneifolia<br />
Sar<strong>co</strong>stemma viminale<br />
Schotia brachypetala<br />
Sclerocarya birrea subsp. caffra<br />
Sideroxylon inerme<br />
Solanum licht<strong>en</strong>steinii<br />
Spirostachys africana<br />
Steganota<strong>en</strong>ia araliacea<br />
Strophanthus speciosus<br />
tarchonanthus camphoratus<br />
te<strong>co</strong>ma cap<strong>en</strong>se<br />
trimeria grandiflora<br />
turraea obtusifolia<br />
Vangueria infausta<br />
Vangueria infausta<br />
Vitex obovata<br />
Withania somnifera<br />
Xerophyta retinervis<br />
Xim<strong>en</strong>ia americana var. microphylla<br />
Xim<strong>en</strong>ia caffra<br />
Zanthoxylum cap<strong>en</strong>se<br />
Ziziphus mucronata<br />
Edible plants<br />
Acacia karroo<br />
Asparagus buchananii<br />
Bauhinia tom<strong>en</strong>tosa<br />
Berchemia zeyheri<br />
Boscia foetida<br />
Carissa bispinosa<br />
Cleome gynandra<br />
TSATE HERITAGE SITE IN SEKHUKHUNELAND<br />
Corchorus trid<strong>en</strong>s<br />
Diospyros lycioides<br />
Dovyalis caffra<br />
Ehretia rigida<br />
Elaeod<strong>en</strong>dron transvaal<strong>en</strong>se<br />
Euclea crispa<br />
Ficus abutilifolia<br />
Ficus glumosa<br />
Ficus tett<strong>en</strong>sis<br />
Grewia dis<strong>co</strong>lor<br />
Grewia flava<br />
Grewia flavesc<strong>en</strong>s<br />
Mimusops zeyheri<br />
Myrothamnus flabellifolius<br />
olea cap<strong>en</strong>sis subsp. <strong>en</strong>ervis<br />
olea europaea subsp. africana<br />
Pappea cap<strong>en</strong>sis<br />
Schotia brachypetala<br />
Sclerocarya birrea<br />
Searsia lancea<br />
Searsia transvaal<strong>en</strong>sis<br />
Vangueria infausta<br />
Vangueria madagascari<strong>en</strong>sis<br />
Vigna unguiculata<br />
Xim<strong>en</strong>ia americana<br />
Xim<strong>en</strong>ia caffra<br />
Ziziphus mucronata<br />
Poisonous plants<br />
A<strong>co</strong>kanthera oppositifolia<br />
Argemone ochroleuca<br />
Asclepias fruti<strong>co</strong>sa<br />
Datura stramonium<br />
Euphorbia <strong>co</strong>operi<br />
Euphorbia ing<strong>en</strong>s<br />
Euphorbia tirucalli<br />
Ficus salicifolia<br />
Gnidia polycephala<br />
Kalanchoe thyrsiflora<br />
Lantana camara<br />
Lippia ja<strong>van</strong>ica<br />
Mundulea sericea<br />
ni<strong>co</strong>tiana glauca<br />
obetia t<strong>en</strong>ax<br />
Pavetta lanceolata<br />
Sar<strong>co</strong>stemma viminale<br />
S<strong>en</strong>ecio retrorsus<br />
Solanum licht<strong>en</strong>steinii<br />
Spirostachys africana<br />
Strophanthus speciosus<br />
tribulus terrestris<br />
Xanthium spinosum<br />
Xanthium strumarium<br />
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DENDRON » No/Nr: 43 » November 2011
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VERTROETEL jY UITHEEMSE INDRINGERPLANTE IN jOU TUIN?<br />
Vertroetel jy uitheemse indringerplante in jou tuin?<br />
Rust<strong>en</strong>burg lê aan <strong>die</strong> voet <strong>van</strong> <strong>die</strong> Magaliesberg<br />
<strong>en</strong> <strong>die</strong> grootste gedeelte <strong>van</strong> <strong>die</strong> stad lê binnein<br />
of is aangr<strong>en</strong>s<strong>en</strong>d aan <strong>die</strong> oorgangsgebied <strong>van</strong><br />
<strong>die</strong> voorgestelde Magaliesberg-biosfeer.<br />
Biosfeer reservate of natuurgebiede is beskermde<br />
gebiede wat <strong>van</strong> internasionale bewaringsbelang is.<br />
Dit is unieke kategorieë <strong>van</strong> beskermde gebiede <strong>en</strong><br />
dit behels ’n kombinasie <strong>van</strong> beide natuurbewaring<br />
sowel as volhoubare b<strong>en</strong>utting <strong>van</strong> natuurlike<br />
hulpbronne. Die hele Magaliesberg-gebied <strong>van</strong>af<br />
Cullinan in <strong>die</strong> ooste tot Pilanesberg<br />
in <strong>die</strong> weste is onder leiding <strong>van</strong> <strong>die</strong><br />
United Nations Educational, Sci<strong>en</strong>tific<br />
and Cultural Organisation (UNESCO),<br />
in <strong>die</strong> finale stadium om as ’n biosfeer<br />
geproklameer te word. Dit sal slegs<br />
<strong>die</strong> sew<strong>en</strong>de geproklameerde biosfeer in Suid-<br />
Afrika wees. Die ander gebiede wat ook as biosfere<br />
verklaar is, is <strong>die</strong> Kogelberg in <strong>die</strong> Wes-Kaap, <strong>die</strong><br />
Weskus, <strong>die</strong> Waterberg, <strong>die</strong> Kruger Nasionale<br />
Park wat <strong>die</strong> Blyderivierpoort insluit, <strong>die</strong> Kaapse<br />
Wynland <strong>en</strong> Vhembe in <strong>die</strong> noorde <strong>van</strong> <strong>die</strong> Limpopo<br />
provinsie, wat Mapungubwe insluit.<br />
‘n Biosfeer is dus <strong>die</strong> biologiese kompon<strong>en</strong>t wat<br />
<strong>die</strong> totale ‘pakket’ <strong>van</strong> alle lew<strong>en</strong>de organismes op<br />
aarde of dan in ’n spesifieke gebied of area, asook<br />
<strong>die</strong> dooie materiaal wat deur <strong>die</strong> lewe tot stand<br />
kom, insluit. Ekologies gesproke is <strong>die</strong> biosfeer<br />
dus ‘n ‘globale ekosisteeem’ <strong>en</strong> dit sluit dus alle<br />
vorme <strong>van</strong> biodiversitiet op <strong>die</strong> aarde of dan in <strong>die</strong><br />
verklaarde gebied in. As gevolg <strong>van</strong> <strong>die</strong> langtermyn<br />
interaksie oor biljo<strong>en</strong>e jare tuss<strong>en</strong> <strong>die</strong> biosfeer <strong>en</strong><br />
ander stelsels (atmosfeer, litosfeer, hidrosfeer, <strong>en</strong>s.)<br />
op <strong>die</strong> aarde is daar bykans nie ’n deel <strong>van</strong> <strong>die</strong><br />
aarde se oppervlakte wat nie ingryp<strong>en</strong>d aangeraak<br />
word <strong>en</strong> verander is deur lew<strong>en</strong>de organismes nie.<br />
Die aarde is immers ’n lew<strong>en</strong>de planeet <strong>en</strong> al <strong>die</strong><br />
organismes het aangehou om <strong>die</strong> aarde tot voordeel<br />
<strong>van</strong> hulself te verander. Die biosfeer kan dus ook<br />
<strong>die</strong> strook <strong>van</strong> lewe op aarde g<strong>en</strong>oem word.<br />
Biodiversiteit is e<strong>en</strong> <strong>van</strong> <strong>die</strong> aarde se grootste bates.<br />
Lewe op aarde voorsi<strong>en</strong> aan <strong>die</strong> m<strong>en</strong>s voedsel, suiwer<br />
<strong>die</strong> lug wat ons inasem, filter <strong>die</strong> water wat ons drink<br />
<strong>en</strong> dit vorm <strong>die</strong> basis <strong>van</strong> ‘n oneindige hoeveelheid<br />
medisyne. Dit sluit ook indirekte voordele in soos<br />
bekamping <strong>van</strong> erosie, regulering <strong>van</strong> <strong>die</strong> klimaat <strong>en</strong><br />
watervlakke. Verder het dit ook ’n kulturele waarde<br />
wat bestaan uit natuurlike landskappe wat manifesteer<br />
Naas Grové<br />
Biodiversiteit is<br />
e<strong>en</strong> <strong>van</strong> <strong>die</strong> aarde se<br />
grootste bates.<br />
in <strong>die</strong> gepaardgaande ontspanningsgeriewe <strong>en</strong><br />
-aktiwiteite wat dit aan m<strong>en</strong>se bied.<br />
Ongelukkig is hier<strong>die</strong> natuurlike bronne onder<br />
geweldige druk. Van <strong>die</strong> grootste bedreigings vir<br />
<strong>die</strong> vernietiging <strong>van</strong> biodiversiteit sluit ongetwyfeld<br />
indringer plantspesies, klimaatverandering,<br />
besoedeling <strong>en</strong> habitat vernietiging of -verandering<br />
in. Dit is dan ook nie snaaks nie dat <strong>die</strong> rol <strong>van</strong> <strong>die</strong><br />
m<strong>en</strong>s in al voorg<strong>en</strong>oemde duidelik sigbaar is. Indi<strong>en</strong><br />
<strong>die</strong> m<strong>en</strong>s dus nie baie gou planne in plek sit om hier<strong>die</strong><br />
drywers <strong>van</strong> biodiversiteit vernietiging suksesvol aan<br />
te spreek nie, sal ons toeskouers<br />
wees <strong>van</strong> ons vernietig<strong>en</strong>de hande<br />
arbeid. Die verlies aan biodiversiteit<br />
het ‘n geweldige negatiewe<br />
uitwerking op <strong>die</strong> integriteit <strong>van</strong><br />
alle ekossisteme (<strong>die</strong> omgewing of<br />
<strong>die</strong> natuur) <strong>en</strong> gepaardgaande daarmee sal <strong>en</strong>ige<br />
poging tot volhoubare b<strong>en</strong>utting <strong>van</strong> <strong>die</strong> natuurlike<br />
hulbronne, in watter vorm ookal, futiel wees. Wanneer<br />
ons biodiversiteit vernietig, verloor ons unieke g<strong>en</strong>e,<br />
spesies <strong>en</strong> ekosisteme asook alles wat <strong>die</strong> m<strong>en</strong>s tot sy<br />
voordeel kan b<strong>en</strong>ut of gebruik.<br />
E<strong>en</strong> <strong>van</strong> <strong>die</strong> grootste probleme vir <strong>die</strong> huidige stand<br />
<strong>van</strong> sake is indringerplante <strong>en</strong> daar is waarskynlik<br />
nie ‘n huishouding in Suid-Afrika wat onskuld kan<br />
pleit nie. Wanneer na uitheemse indringerplante<br />
verwys word is dit nie <strong>die</strong>selfde konteks as <strong>die</strong><br />
fiksie rolpr<strong>en</strong>te se storie lyne oor vreemde vlieënde<br />
voorwerpe nie. Inte<strong>en</strong>deel dit verwys na biologiese<br />
spesies soos plante, fungi, bakterieë <strong>en</strong> <strong>die</strong>re wat<br />
buite hul natuurlike habitat verspreiding ’n ernstige<br />
bedreiging inhou vir <strong>die</strong> biodiversiteit <strong>van</strong> <strong>die</strong><br />
‘nuwe’ gebied waar binne hulle hulself tuismaak.<br />
’n Spesie kan uitheems wees, sonder dat dit ’n<br />
indringer is. Dink maar aan al <strong>die</strong> graan, mielies,<br />
sonneblom, aartappels, <strong>en</strong>s., wat almal hul<br />
oorsprong elders in <strong>die</strong> wêreld het <strong>en</strong> tog voedsel<br />
aan miljo<strong>en</strong>e m<strong>en</strong>se dwarsoor <strong>die</strong> wêreld verskaf.<br />
Dus is alle uitheemse spesies nie ongew<strong>en</strong>s nie.<br />
Om indringer status te verdi<strong>en</strong> moet <strong>die</strong> spesie<br />
aangeplant word, dit moet oorleef <strong>en</strong> tot so ’n mate<br />
floreer dat dit <strong>die</strong> natuurlike inheemse spesies<br />
heeltemal oorheers of verdring. ’n Goeie voorbeeld<br />
hier<strong>van</strong> is <strong>die</strong> uitheemse Australiese Acacia spesies<br />
wat oral op <strong>die</strong> Hoëveld <strong>die</strong> natuurlike grasveldekosisteme<br />
binne gedring <strong>en</strong> totaal versteur het. Al<br />
<strong>die</strong> indringer plant spesies het dus ’n paar dinge in<br />
geme<strong>en</strong>:<br />
• Hulle groei <strong>en</strong> versprei baie vinnig.<br />
• Hulle het almal <strong>die</strong> vermoë om hul saad oor ’n<br />
wye gebied te versprei.<br />
• Die plante is fisiologies goed aangepas by<br />
<strong>die</strong> nuwe klimaat kondisies <strong>en</strong> hulle kan<br />
so in verskill<strong>en</strong>de grondtipes <strong>en</strong> in uiterste<br />
klimaatomstandighede floreer.<br />
Per definisie is <strong>die</strong> uitheemse plante nie slegte<br />
spesies nie, hulle het net ’n pot<strong>en</strong>siële vernietig<strong>en</strong>de<br />
uitwerking op <strong>die</strong> biodiversitiet <strong>van</strong> <strong>die</strong> natuurlike<br />
omgewing, indi<strong>en</strong> dit nie behoorlik beheer word nie.<br />
Suid-Afrika huisves tans meer as 25 000 uitheemse<br />
plant spesies.<br />
Dit kos <strong>die</strong> belastingbetaler jaarliks<br />
biljo<strong>en</strong>e rande om uitheemse<br />
indringerplante te bestry.<br />
Daar is in totaal 220 uitheemse plantspesies<br />
ingevolge <strong>die</strong> Die WET OP DIE BEWARING VAN<br />
LANDBOUHULPBRONNE, 1983 (WET No. 43 VAN<br />
1983 soos gewysig in MAART 2001) as ongew<strong>en</strong>s in<br />
SWAARDVARING » nephrolepis e<strong>za</strong>ltata<br />
VERTROETEL jY UITHEEMSE INDRINGERPLANTE IN jOU TUIN?<br />
review<br />
review<br />
drie verskill<strong>en</strong>de kategorieë geklassifiseer. Hier<strong>die</strong><br />
plante het reeds ’n gebied <strong>van</strong> 15 miljo<strong>en</strong> hektaar<br />
(so groot soos KwaZulu-Natal) binnegedring. Daar is<br />
beswaarlik nie ’n bergkompleks, bosveld-, sa<strong>van</strong>na-<br />
of grasveldbiome in Suid-Afrika wat nie in ‘n mindere<br />
of meerdere mate deur e<strong>en</strong> of meer indringerplante<br />
bedreig word nie. Dit kos <strong>die</strong> belastingbetaler jaarlks<br />
biljo<strong>en</strong>e rande om <strong>die</strong> plante te bestry.<br />
Baie <strong>van</strong> hier<strong>die</strong> plante word tans binne in huise,<br />
in tuine <strong>en</strong> in visdamme aangehou <strong>en</strong> vertroetel.<br />
Van <strong>die</strong> algem<strong>en</strong>e indringers wat ek oral in tuine<br />
opmerk is swaardvaring (Nephrolepis exaltata –<br />
uitgesonder steriele kultivars), meeste <strong>van</strong> <strong>die</strong> privet<br />
bome <strong>en</strong> struike (Lingustrum spp.), maandblomme<br />
(Ipomoea alba, I. lndica<strong>en</strong> I. purpurea), mak sering<br />
(Melia azedarach), selonsroos (Nerium oleander –<br />
behalwe gekultiveerde plante met dubbel blomme),<br />
skubliesroos (Litsea glutinosa ), waterslaai (Pistia<br />
stratiotes ) <strong>en</strong> water hiasinte (Eichhornia crassipes).<br />
Die lys is e<strong>en</strong>voudig te lank om by te hou.<br />
Van ons sypaadjies <strong>en</strong> winkels<strong>en</strong>trum parkeer-areas<br />
is besoedel met indringerplante soos <strong>die</strong> wynboom<br />
of belhambra (Phytolacca dioica), Brasiliaanse<br />
peperboom (Schinus terebinthifolius), vlinder-orgideë<br />
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review<br />
VERTROETEL jY UITHEEMSE INDRINGERPLANTE IN jOU TUIN?<br />
(Bauhinia purpurea <strong>en</strong> B. variegata), Kanferboom<br />
(Cinnamomum camphora), jakaranda (Jacaranda<br />
mimosifolia), treur-wilger (Salix babylonica,<br />
wat nie verwar moet word met <strong>die</strong> inheemse<br />
wilgers nie), moerbei (Morus alba - uitgesonder<br />
<strong>die</strong> kultivar P<strong>en</strong>dula wat as wortelstok gebruik<br />
word), wasboom (Rhus succedanea), Tipu-boom<br />
SELONROOS » nerium oleander<br />
(Tipuana tipu), sisal (Agave sisalana), Australiese<br />
silwer-eik (Grevillea robusta), Australiese kasuur<br />
(Pittosporum undulatum), Spaanse-riet (Arundo<br />
donax), pampasgras (Cortaderia selloana –<br />
uitgesonder steriele kultivars), geel-kassia (S<strong>en</strong>na<br />
didymobotrya), lukwart (Eriobotrya japonica),<br />
geelklokkies (Te<strong>co</strong>ma stans), koejawel (Psidium<br />
guajava) <strong>en</strong> alle saaddra<strong>en</strong>de vorms <strong>van</strong> <strong>die</strong> lantana<br />
spesies (Lantana camara).<br />
Ongeveer 10% <strong>van</strong> Suid-Afrika se jaarlikse<br />
watervoorraad word deur indringer plante<br />
opgebruik. Indringer plante het ge<strong>en</strong> of weinig<br />
natuurlike vyande in Suid-Afrika, met <strong>die</strong> gevolg<br />
dat hulle <strong>die</strong> inheemse plante verdring <strong>en</strong> later<br />
vernietig. Groot stande uitheemse plante<br />
veroorsaak erosie <strong>en</strong> dit skep ‘n brandgevaar. In<br />
’n gebied wat as biosfeer verklaar is, is <strong>die</strong> vereiste<br />
dus <strong>die</strong> bewaring <strong>van</strong> <strong>die</strong> diversiteit <strong>van</strong> plante, <strong>die</strong>re<br />
<strong>en</strong> mikro-organismes wat almal saam <strong>die</strong> lew<strong>en</strong>de<br />
biosfeer uitmaak. Vanselfsprek<strong>en</strong>d betek<strong>en</strong> dit dat<br />
almal wat <strong>van</strong> Cullinan tot Pilanesberg onlosmaaklik<br />
aan <strong>die</strong> Magaliesberg verbind is <strong>en</strong> sekere<br />
verantwoordelikhede het te<strong>en</strong>oor <strong>die</strong> bewaring <strong>van</strong><br />
hier<strong>die</strong> voorgestelde biosfeer.<br />
Dit het derhalwe nodig geword dat iets drasties<br />
gedo<strong>en</strong> word om <strong>die</strong> verspreiding <strong>en</strong> aanplanting<br />
<strong>van</strong> <strong>die</strong> plante in te kort of selfs op te skort.<br />
Die gevaar <strong>van</strong> indringerplante lê daarin, dat dit<br />
digte stande vorm wat <strong>die</strong> natuurlike plantegroei<br />
verdring soos gesi<strong>en</strong> kan word in <strong>die</strong> geval <strong>van</strong><br />
Lantana camara <strong>en</strong> Te<strong>co</strong>ma stans wat oral in <strong>die</strong><br />
gebied ter sprake voorkom. Omdat <strong>die</strong> plante ge<strong>en</strong><br />
of min natuurlike vyande het <strong>en</strong> onder dié gunstige<br />
omstandighede groot hoeveelhede saad per jaar<br />
produseer kan <strong>die</strong> verspreiding daar<strong>van</strong> e<strong>en</strong>voudig<br />
nie maklik beheer word nie.<br />
Daar is verskeie maniere om <strong>die</strong> probleem aan te<br />
spreek <strong>en</strong> ’n goeie wegspring plek is sekerlik om<br />
te begin met ’n bewusmaking <strong>en</strong> inligtingsveldtog.<br />
Sodra ’n m<strong>en</strong>s weet waarna om te kyk <strong>en</strong> meer <strong>van</strong><br />
<strong>die</strong> indringer plante weet kan daar daadwerklik tot<br />
aksie oorgegaan word. Uiteindelik kan daar dan<br />
met <strong>die</strong> k<strong>en</strong>nis tot ons beskikking tot e<strong>en</strong> <strong>van</strong> <strong>die</strong><br />
volg<strong>en</strong>de aksies oorgegaan word:<br />
• Voorkoming is <strong>die</strong> eerste lyn <strong>van</strong> verdediging<br />
te<strong>en</strong> uitheemse indringer plante. Op <strong>die</strong><br />
langduur is dit ook <strong>die</strong> goedkoopste <strong>en</strong> mees<br />
praktiese metode. Dit behels k<strong>en</strong>nis <strong>van</strong> <strong>die</strong><br />
wet <strong>en</strong> watter <strong>van</strong> <strong>die</strong> uitheemse spesies as<br />
ongew<strong>en</strong>ste indringerplante geproklameer<br />
is. Dit behels ook metodes hoe om hoë<br />
risiko gebiede waar <strong>die</strong> plante voorkom te<br />
id<strong>en</strong>tifiseer <strong>en</strong> maatreëls in plek te sit vir <strong>die</strong><br />
beheer daar<strong>van</strong>. Sonder <strong>en</strong>ige moeite kan<br />
elke huishouding, deur nie <strong>van</strong> <strong>die</strong> ongew<strong>en</strong>ste<br />
plante aan te hou nie, klaar help in <strong>die</strong> proses<br />
<strong>van</strong> voorkoming.<br />
• Uitroei <strong>van</strong> <strong>die</strong> plante uit ’n bepaalde gebied.<br />
Hoe langer ’n uitheemse indringer alle<strong>en</strong><br />
gelaat word, hoe moeiliker <strong>en</strong> duurder word dit<br />
om dit te beheer. Deur <strong>die</strong> plante te verwyder<br />
is dikwels goed g<strong>en</strong>oeg vir <strong>die</strong> natuurlike<br />
plantspesies om hulself weer te hervestig.<br />
• Beheer <strong>die</strong> verspreiding <strong>van</strong> <strong>die</strong> plante met<br />
doelgerigte metodes om te verhoed dat <strong>die</strong><br />
plante buite ’n bepaalde geografiese gebied<br />
versprei. Die doel is om <strong>die</strong> plant populasie<br />
te beheer <strong>en</strong> te verminder sodat dit nie hande<br />
uitruk nie. Sodra <strong>die</strong> populasie onder ’n seker<br />
groei kom sal <strong>die</strong> natuurlike plante g<strong>en</strong>oeg<br />
voorsprong hê om hulself weer te hervestig <strong>en</strong><br />
so <strong>die</strong> uitheemse plante natuurlik verdryf.<br />
Navorsing dui daarop dat daar mikroskopies klein<br />
bakterieë bestaan wat doeltreff<strong>en</strong>der as bome is in<br />
<strong>die</strong> vervaardiging <strong>van</strong> suikers. Wet<strong>en</strong>skaplikes beoog<br />
om <strong>die</strong> klein ‘moderne‘ bakterieë in te span om te help<br />
voorsi<strong>en</strong> aan <strong>die</strong> to<strong>en</strong>em<strong>en</strong>de wêreldvraag na voedsel.<br />
In <strong>die</strong> volg<strong>en</strong>de paragrawe word meer agtergrond<br />
verskaf oor waarom <strong>die</strong> fotosintese <strong>van</strong> ‘moderne’<br />
sianobakterieë beter as dié <strong>van</strong> landplante soos bome<br />
is, watter soorte fotosintese in landplante voorkom <strong>en</strong><br />
hoe <strong>die</strong> m<strong>en</strong>s <strong>die</strong> fotosinteseproses kunsmatig kan<br />
inspan vir verhoogde voedselproduksie.<br />
Hoe bome se produktiwiteit agter geraak het<br />
Volg<strong>en</strong>s <strong>die</strong> evolusieteorie bestaan sianobakterieë<br />
wat kan fotosinteer al drie miljard (3000 miljo<strong>en</strong>) jaar<br />
op aarde. Hier<strong>die</strong> primitiewe bakterieë het fotosintese<br />
uitgevoer in ’n omgewing wat baie anders is as dit wat<br />
ons <strong>van</strong>dag k<strong>en</strong>. Die atmosfeer het to<strong>en</strong>tertyd ’n veel<br />
hoër kons<strong>en</strong>trasie koolsuurgas bevat as <strong>die</strong> 0.039%<br />
<strong>van</strong> <strong>die</strong> huidige atmosfeer, <strong>en</strong> <strong>die</strong> kons<strong>en</strong>trasie<br />
suurstof (O 2 ) was destyds veel laer as <strong>die</strong> huidige<br />
21%. Bow<strong>en</strong>di<strong>en</strong> het <strong>die</strong> bakterieë in water (oseane,<br />
mere) gelewe. Die fotosinteseproses wat deur hulle<br />
gebruik is, was vir daar<strong>die</strong> omstandighede geskik.<br />
Uit <strong>die</strong> beskikbare gegew<strong>en</strong>s lei wet<strong>en</strong>skaplikes af dat<br />
sekere e<strong>en</strong>voudige organismes (protista) ’n miljard<br />
jaar gelede <strong>van</strong> hier<strong>die</strong> primitiewe sianobakterieë in<br />
hulle selle opg<strong>en</strong>eem <strong>en</strong> ‘ge<strong>van</strong>ge’ gehou het. Die<br />
sianobakterieë is ‘beskerm’ binne <strong>die</strong> selle waardeur<br />
hulle opg<strong>en</strong>eem is, <strong>en</strong> het nog steeds deur fotosintese<br />
suikers geproduseer waardeur <strong>die</strong> selkompleks<br />
gebaat het. ’n Simbiotiese verhouding het so ontstaan<br />
<strong>en</strong> <strong>die</strong> ‘sianobakterieë’ het binne selle ontwikkel tot<br />
dit wat ons <strong>van</strong>dag as chloroplaste k<strong>en</strong> (Figuur 1).<br />
Alhoewel <strong>die</strong> fotosinteseproses <strong>van</strong> <strong>die</strong> chloroplaste in<br />
selle basies vergelykbaar is met <strong>die</strong> fotosinteseproses<br />
<strong>van</strong> <strong>die</strong> vrylew<strong>en</strong>de primitiewe sianobakterieë <strong>van</strong><br />
destyds, is hulle totaal afhanklik <strong>van</strong> <strong>die</strong> selle waarin<br />
hulle voorkom. So byvoorbeeld, bevat chloroplaste<br />
nie al <strong>die</strong> nodige g<strong>en</strong>e vir <strong>die</strong> fotosinteseproses nie,<br />
maar kom sommige <strong>van</strong> <strong>die</strong> noodsaaklike g<strong>en</strong>e in<br />
<strong>die</strong> nukleusse <strong>van</strong> <strong>die</strong> selle voor. Die funksionering<br />
<strong>van</strong> chloroplaste word dus deur <strong>die</strong> selle waarin<br />
hulle voorkom, beheer. Alle landplante het uit <strong>die</strong><br />
aan<strong>van</strong>klike simbiotiese verhouding ontwikkel met<br />
<strong>die</strong> gevolg dat <strong>die</strong> basiese fotosinteseproses wat hulle<br />
gebruik om voedsel (soos suikers) te vervaardig, ’n<br />
miljard jaar gelede al ontwikkel is!<br />
Klink hier<strong>die</strong> evolusionêre si<strong>en</strong>ing dat chloroplaste<br />
eers vryswemm<strong>en</strong>de sianobakterieë was,<br />
Is bome swak kosmakers?<br />
fanie de Meillon<br />
IS BOME SWAK KOSMAKERS?<br />
vergesog? Die argum<strong>en</strong>te wat hier<strong>die</strong> si<strong>en</strong>ing<br />
staaf, kan op Wikipedia onder “Endosymbiotic<br />
theory” gelees word.<br />
FIG 1 Selle <strong>van</strong> <strong>die</strong> mosplant Plagiomnium affine<br />
waarin <strong>die</strong> gro<strong>en</strong> chloroplaste duidelik gesi<strong>en</strong><br />
kan word. Wikipedia: Chloroplast.<br />
Die probleem met <strong>die</strong> fotosinteseproses <strong>van</strong><br />
bome<br />
Natuurliefhebbers, <strong>en</strong> veral boomliefhebbers, is<br />
g<strong>en</strong>eig om <strong>die</strong> Natuur as volmaak te beskou. Tog blyk<br />
dit dat daar uit ’n m<strong>en</strong>slike oogpunt ’n ‘probleem’ is<br />
met <strong>die</strong> heel eerste reaksie <strong>van</strong> <strong>die</strong> fotosinteseproses<br />
in <strong>die</strong> chloroplaste <strong>van</strong> <strong>die</strong> selle <strong>van</strong> bome <strong>en</strong> alle<br />
ander gro<strong>en</strong> plante.<br />
RuBP CO 2 O 2<br />
review<br />
review<br />
FIG 2 ’n Skematiese voorstelling wat <strong>die</strong><br />
kompetisie tuss<strong>en</strong> CO 2 <strong>en</strong> O 2 vir bindplek op <strong>die</strong><br />
<strong>en</strong>siem Rubis<strong>co</strong> aandui.<br />
In <strong>die</strong> heel eerste reaksie verbind<br />
koolsuurgasmolekule (CO 2 ) met molekule <strong>van</strong><br />
ribulose-1,5-bisfosfaat (RuBP: ’n ribose-suiker met<br />
twee fosfaatgroepe aan). Die reaksie is slegs moontlik<br />
deur <strong>die</strong> bemiddeling <strong>van</strong> ’n <strong>en</strong>siem waar<strong>van</strong> <strong>die</strong><br />
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review<br />
IS BOME SWAK KOSMAKERS?<br />
naam as Rubis<strong>co</strong> afgekort is (Figuur 2). Rubis<strong>co</strong> werk<br />
heel gaaf om <strong>die</strong> reaksie te kataliseer mits <strong>die</strong> CO 2 -<br />
kons<strong>en</strong>trasie hoog is. Drie miljard jaar gelede, toe <strong>die</strong><br />
atmosferiese CO 2 -kons<strong>en</strong>trasie hoog was, sou Rubis<strong>co</strong><br />
dus goed in primitiewe sianobakterieë gefunksioneer<br />
het. Die Rubis<strong>co</strong> <strong>en</strong>siem vaar egter nie so goed<br />
onder huidige atmosferiese toestande <strong>van</strong> ’n lae CO 2 -<br />
<strong>en</strong> hoë O 2 -kons<strong>en</strong>trasie nie want <strong>die</strong> O 2 -molekule<br />
kompeteer nou met <strong>die</strong> CO 2 -molekule vir bindplek<br />
aan <strong>die</strong> <strong>en</strong>siemmolekule. We<strong>en</strong>s <strong>die</strong> kompetisie<br />
tuss<strong>en</strong> CO 2 - <strong>en</strong> O 2 -molekule bind daar dus minder<br />
CO 2 -molekule per sekonde aan <strong>die</strong> Rubis<strong>co</strong>-<strong>en</strong>siem.<br />
Boonop veroorsaak <strong>die</strong> binding <strong>van</strong> <strong>die</strong> O 2 -molekule<br />
aan Rubis<strong>co</strong> dat afwyk<strong>en</strong>de reaksies (fotorespirasie)<br />
plaasvind wat fotosintese minder doeltreff<strong>en</strong>d maak.<br />
Kan bome se fotosintese deur mutasies<br />
verbeter word?<br />
Veronderstel dat daar ’n ‘gunstige’ mutasie in <strong>die</strong><br />
chloroplaste <strong>van</strong> ’n blaar sou plaasvind waardeur ’n<br />
beter Rubis<strong>co</strong> <strong>en</strong>siem sou ontstaan. So ’n gunstige<br />
mutasie kan ongelukkig nie na ander volwasse<br />
blaarselle of na ander blare versprei nie want<br />
chloroplaste migreer nie tuss<strong>en</strong> selle nie. As <strong>die</strong><br />
blaar met <strong>die</strong> gunstige mutasie dus verouder <strong>en</strong><br />
afval, sal <strong>die</strong> mutasie verlore gaan. Om verskeie<br />
redes is <strong>die</strong> kanse maar klein dat ’n gunstige<br />
mutasie in <strong>en</strong>kele chloroplaste <strong>van</strong> ’n plant na ’n<br />
nageslag oorgedra kan word.<br />
Wat <strong>die</strong> vrylew<strong>en</strong>de sianobakterieë in <strong>die</strong> oseane<br />
<strong>en</strong> mere betref, is <strong>die</strong> situasie anders. Mutasies kan<br />
makliker plaasvind, <strong>en</strong> ’n sianobakteriesel met ’n<br />
gunstige mutasie kan geredelik aanteel <strong>en</strong> in groot<br />
hoeveelhede voorkom. Dit is skynbaar wat 0.4 miljard<br />
(400 miljo<strong>en</strong>) jaar gelede gebeur het. Op daar<strong>die</strong><br />
stadium het <strong>die</strong> CO 2 -kons<strong>en</strong>trasie <strong>van</strong> <strong>die</strong> atmosfeer<br />
beduid<strong>en</strong>d begin daal <strong>en</strong> ‘moderne’ sianobakterieë<br />
het toe ontstaan wat daarby kon aanpas. Die<br />
aanpassing het behels dat mikrokompartem<strong>en</strong>te<br />
in <strong>die</strong> sianobakterieë ontstaan het <strong>en</strong> daarby het<br />
membraan-‘pompe’ ontwikkel wat CO 2 aktief in <strong>die</strong><br />
mikrokompartem<strong>en</strong>te inpomp. Sodo<strong>en</strong>de word ’n<br />
hoë CO 2 -kons<strong>en</strong>trasie in <strong>die</strong> mikrokompartem<strong>en</strong>te<br />
verkry <strong>en</strong> kon <strong>die</strong> Rubis<strong>co</strong>-<strong>en</strong>siem <strong>van</strong> <strong>die</strong> ‘moderne’<br />
vrylew<strong>en</strong>de sianobakterieë effektief funksioneer.<br />
Kan landplante dan nie ook koolsuurgas<br />
kons<strong>en</strong>treer nie?<br />
Ja inderdaad beskik sekere landplante beskik wel<br />
oor meganismes om CO 2 te kons<strong>en</strong>treer maar hulle<br />
maak nie <strong>van</strong> CO 2 -‘pompe’ <strong>en</strong> mikrokompartem<strong>en</strong>te<br />
gebruik nie. Hulle is egter in <strong>die</strong> minderheid <strong>en</strong><br />
verreweg <strong>die</strong> meeste soorte plante maak nog <strong>van</strong> <strong>die</strong><br />
‘primitiewe’ proses (C 3 -fotosintese) gebruik sonder<br />
dat <strong>die</strong> CO 2 vooraf gekons<strong>en</strong>treer word. Die gewone<br />
fotosintese word C 3 -fotosintese g<strong>en</strong>oem omdat <strong>die</strong><br />
eerste stabiele fotosinteseproduk wat ontstaan, se<br />
molekule drie koolstofatome lank is.<br />
Sekere ekonomies belangrike landplante (suikerriet,<br />
mielies, sorghum) beskik oor ‘n fotosinteseproses<br />
(C 4 -fotosintese) waardeur CO 2 gekons<strong>en</strong>treer word<br />
<strong>en</strong> <strong>die</strong> soort fotosintese is eers in <strong>die</strong> sestigerjare<br />
<strong>van</strong> <strong>die</strong> vorige eeu ontdek. Die blare <strong>van</strong> C 4 -plante<br />
is anatomies aangepas om <strong>die</strong> kons<strong>en</strong>trering <strong>van</strong><br />
CO 2 moontlik te maak. Eerst<strong>en</strong>s word <strong>die</strong> CO 2<br />
doeltreff<strong>en</strong>d in gewone blaarselle gebind deur<br />
’n karboksilase-<strong>en</strong>siem <strong>en</strong> dus nie deur Rubis<strong>co</strong><br />
nie. Die appelsuur of ander C 4 -verbinding wat so<br />
gevorm word, word na dikwandige skedeselle<br />
wat om <strong>die</strong> blaar-are gerangskik is, vervoer. Daar<br />
word <strong>die</strong> C 4 -verbinding ontbind <strong>en</strong> word <strong>die</strong> CO 2<br />
weer vrygestel. Die CO 2 kan nie maklik uit hier<strong>die</strong><br />
dikwandige selle ontsnap nie <strong>en</strong> kom dus in hoë<br />
kons<strong>en</strong>trasies daarin voor, waar dit dan sonder <strong>die</strong><br />
belemmering <strong>van</strong> O 2 aan <strong>die</strong> Rubis<strong>co</strong>-<strong>en</strong>siem kan<br />
bind <strong>en</strong> <strong>die</strong> normale ‘primitiewe’ C 3 -fotosintese vind<br />
dan in <strong>die</strong> chloroplaste <strong>van</strong> <strong>die</strong> skedeselle plaas.<br />
Die <strong>en</strong>igste boomspesie wat tot dusver ontdek is<br />
wat tot C 4 -fotosintese in staat is, is ’n Euphorbia.<br />
Die derde soort fotosintese wat deur sekere<br />
landplante uitgevoer word <strong>en</strong> waardeur CO 2 vooraf<br />
gekons<strong>en</strong>treer word, word CAM-fotosintese g<strong>en</strong>oem,<br />
kom in sekere vetplante voor <strong>en</strong> stel hulle in staat om<br />
in dor gebiede te groei. Die plante se huidmondjies<br />
is, in te<strong>en</strong>stelling met alle ander plante, bedags toe <strong>en</strong><br />
snags oop. Die CO 2 kom <strong>die</strong> plante dus snags binne,<br />
word deur ’n karboksilase-<strong>en</strong>siem in gewone selle<br />
gebind <strong>en</strong> <strong>die</strong> suur wat so ontstaan, hoop gedur<strong>en</strong>de<br />
<strong>die</strong> nag in <strong>die</strong> selle op. Sogg<strong>en</strong>s, wanneer <strong>die</strong> son<br />
opkom, gaan <strong>die</strong> huidmondjies toe <strong>en</strong> <strong>die</strong> suur ontbind<br />
om CO 2 vry te stel. Die CO 2 kan nou nie ontsnap nie<br />
<strong>en</strong> <strong>die</strong> toe huidmondjies verhoed ook dat <strong>die</strong> plante<br />
bedags water verloor. Omdat <strong>die</strong> CO 2 -kons<strong>en</strong>trasie<br />
binne <strong>die</strong> plant sogg<strong>en</strong>s hoog is wanneer <strong>die</strong> son skyn,<br />
kan dit aan <strong>die</strong> Rubis<strong>co</strong> bind sonder belemmering <strong>van</strong><br />
O 2 <strong>en</strong> <strong>die</strong> ‘primitiewe’ C 3 - fotosintese vind plaas in <strong>die</strong><br />
chloroplaste <strong>van</strong> <strong>die</strong> blaarselle. Vetplante wat CAMfotosintese<br />
gebruik, groei baie stadiger as ander<br />
plante. Die epifitiese boom Clusia rosea is uitsonderlik<br />
deurdat dit CAM-fotosintese bedryf.<br />
Planne om <strong>die</strong> fotosinteseproses te manipuleer<br />
Die jongste planne behels om <strong>die</strong> CO 2 -‘pompe’<br />
(spesiale proteï<strong>en</strong>e) <strong>van</strong> ‘moderne’ sianobakterieë<br />
in <strong>die</strong> chloroplaste <strong>van</strong> plantselle in te bou. Twee<br />
<strong>van</strong> <strong>die</strong> pompe word deur ’n <strong>en</strong>kele ge<strong>en</strong> gekodeer<br />
wat <strong>die</strong> plan dus heel uitvoerbaar behoort te maak<br />
met <strong>die</strong> hulp <strong>van</strong> moderne ge<strong>en</strong>tegnologie. Met <strong>die</strong><br />
verhoogde CO 2 in <strong>die</strong> chloroplaste behoort Rubis<strong>co</strong><br />
beter te funksioneer <strong>en</strong> sal plantproduksie sdo<strong>en</strong>de<br />
opgestoot kan word.<br />
’n Meer ambisieuse plan is om <strong>die</strong> g<strong>en</strong>e vir<br />
mikrokompartem<strong>en</strong>te wat CO 2 kan kons<strong>en</strong>treer<br />
(karboksisome) uit sianobakterieë te kry <strong>en</strong><br />
na plantselle oor te dra. Karboksisome bestaan<br />
hoofsaaklik uit membrane wat sodanig uit proteï<strong>en</strong>e<br />
opgebou is dat CO 2 moeilik daaruit kan ontsnap.<br />
Daarby bevat hulle pompe wat CO 2 aktief na binnedra.<br />
Die kuns is dus om <strong>die</strong> hele stel <strong>van</strong> nege g<strong>en</strong>e wat<br />
vir karboksisome <strong>en</strong> meegaande <strong>en</strong>sieme kodeer,<br />
susksesvol na plantselle oor te dra sodat dit met<br />
<strong>die</strong> werking <strong>van</strong> <strong>die</strong> chloroplaste kan integreer. Die<br />
navorser Martin Warr<strong>en</strong> <strong>en</strong> sy span het al daarin<br />
geslaag om kunsmatige mikrosome in <strong>die</strong> bakterie<br />
Escherichia <strong>co</strong>li in te bou <strong>en</strong> hulle dink dis haalbaar om<br />
’n kunsmatige karboksisoom saam te stel.<br />
Nog meer ambisieus, <strong>en</strong> aansi<strong>en</strong>lik moeiliker,<br />
is <strong>die</strong> plan om <strong>die</strong> hele battery g<strong>en</strong>e wat vir C 4 -<br />
fotosintese b<strong>en</strong>odig word, na gewone C 3 -plante oor<br />
te dra. Baie g<strong>en</strong>e is hierby betrokke: g<strong>en</strong>e vir sowel<br />
spesiale <strong>en</strong>sieme as vir anatomiese veranderings om<br />
dikwandige skedeselle om <strong>die</strong> vaatbondels te verkry.<br />
Navorsers het al daarin geslaag om <strong>die</strong> g<strong>en</strong>e vir<br />
<strong>en</strong>kele <strong>van</strong> <strong>die</strong> spesiale C 4 -<strong>en</strong>sieme na rysplante oor<br />
te dra maar dit het nog ge<strong>en</strong> to<strong>en</strong>ame in rysproduksie<br />
tot gevolg gehad nie.<br />
Die stikstof probleem<br />
Plante b<strong>en</strong>odig groot hoeveelhede stikstof vir <strong>die</strong><br />
fotosintese-masjinerie, <strong>en</strong> veral vir <strong>die</strong> sintese <strong>van</strong><br />
<strong>die</strong> relatief groot hoeveelhede Rubis<strong>co</strong>-<strong>en</strong>siem wat<br />
b<strong>en</strong>odig word. Beperkte hoeveelhede stikstof in<br />
<strong>die</strong> vorm <strong>van</strong> nitrate, ammonium <strong>en</strong> urea kom egter<br />
in grond voor. Dit het aanleiding gegee tot nog<br />
’n opwind<strong>en</strong>de droom: om plante deur g<strong>en</strong>etiese<br />
manipulering so te verander dat hulle <strong>die</strong> stikstofgas<br />
in <strong>die</strong> atmosfeer kan b<strong>en</strong>ut. Stikstof (N 2 ) is chemies ’n<br />
baie onaktiewe gas maar wat in groot hoeveelhede<br />
voorkom – amper 78% <strong>van</strong> <strong>die</strong> atmosfeer.<br />
Omdat stikstof so inert is, is dit moeilik om dit na<br />
ammonium of nitrate om te skakel. Wat so verstomm<strong>en</strong>d<br />
is, is dat ge<strong>en</strong> plante dit nog op hulle eie kon regkry<br />
nie, behalwe in assosiasie met heel klein onsigbare<br />
IS BOME SWAK KOSMAKERS?<br />
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review<br />
mikroörganismes. Mikroskopies klein bakterieë<br />
(Rhizobium, Azotobacter, <strong>en</strong> ander) do<strong>en</strong> wat ge<strong>en</strong><br />
reuseboom nog op sy eie kon regkry nie.<br />
Peulplante, soos doringbome, kan in simbiose met<br />
Rhizobium-bakterieë wel stikstof bind. Die bakterieë<br />
word in knoppies op <strong>die</strong> wortels <strong>van</strong> peulplante<br />
aangehou maar <strong>die</strong> hele proses om <strong>die</strong> bakterieë<br />
in <strong>die</strong> wortelknoppies te huisves <strong>en</strong> in assosiasie<br />
met hulle stikstof te bind, is so ingewikkeld dat<br />
wet<strong>en</strong>skaplikes liewers wil probeer om <strong>die</strong> masjinerie<br />
vir N-binding uit <strong>die</strong> bakterieë te verkry <strong>en</strong> dit na <strong>die</strong><br />
chloroplaste <strong>van</strong> blaarselle oor te dra. Die voordeel<br />
daar<strong>van</strong> is dat chloroplaste alreeds verskeie <strong>van</strong><br />
<strong>die</strong> <strong>en</strong>sieme bevat wat vir N-binding nodig is, sodat<br />
‘slegs’ agt g<strong>en</strong>e i.p.v. 20 g<strong>en</strong>e <strong>van</strong> bakterieë na<br />
chloroplaste oorgedra hoef te word. Die nadeel is dat<br />
<strong>die</strong> binnekant <strong>van</strong> chloroplaste suurstof bevat, maar<br />
dat <strong>die</strong> hoofspeler in N-binding, naamlik <strong>die</strong> <strong>en</strong>siem<br />
nitrog<strong>en</strong>ase, slegs in ’n suurstof-vrye omgewing<br />
aktief is. E<strong>en</strong> oplossing vir <strong>die</strong> probleem sal wees om<br />
<strong>die</strong> bakterie Azotobacter se truuk uit te haal, naamlik<br />
om N-binding snags te do<strong>en</strong> wanneer fotosintese<br />
nie plaasvind nie. ’n Ander moontlike oplossing<br />
sou wees om <strong>die</strong> g<strong>en</strong>e vir N-binding in wortels te<br />
laat funksioneer waar fotosintetiese suurstof nie ’n<br />
probleem behoort te wees nie.<br />
Daar is wet<strong>en</strong>skaplikes by universiteite, institute <strong>en</strong><br />
by private firmas wat hard daaraan werk om al <strong>die</strong><br />
drome te realiseer. Die vordering op tegnologiese<br />
gebied is so snel dat dit waarskynlik slegs <strong>en</strong>kele jare<br />
sal wees voordat voedselproduksie op bog<strong>en</strong>oemde<br />
innover<strong>en</strong>de wyses drasties verhoog sal word.<br />
En ons geliefde bome – hoe lank voordat hulle in<br />
wet<strong>en</strong>skaplikes se visier kom? Wel, eksperim<strong>en</strong>tering<br />
word gewoonlik eers met vinnig-groei<strong>en</strong>de plante soos<br />
e<strong>en</strong>jariges <strong>en</strong> met krities-belangrike voedselgewasse<br />
soos rys uitgevoer voordat vrugtebome aan <strong>die</strong><br />
beurt sal kom. Intuss<strong>en</strong> bly <strong>die</strong> m<strong>en</strong>sdom steeds<br />
afhanklik <strong>van</strong> <strong>die</strong> ‘primitiewe’ <strong>en</strong> ‘ondoeltreff<strong>en</strong>de’<br />
fotosinteseproses waardeur bome <strong>en</strong> alle ander gro<strong>en</strong><br />
plante op aarde groei <strong>en</strong> gedy <strong>en</strong> tot voordeel <strong>van</strong> <strong>die</strong><br />
m<strong>en</strong>sdom produseer.<br />
Verwysings:<br />
1. Holmes, Bob. 2011. Billion-year upgrade. New Sci<strong>en</strong>tist,<br />
Feb., pp 42-45.<br />
2. Wikipedia: Chloroplast.<br />
3. Wikipedia: Endosymbiotic theory.<br />
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NEW TREE SPECIES DISCOVERED IN KWAZULU-NATAL<br />
New tree species dis<strong>co</strong>vered in KwaZulu-Natal!<br />
A newly dis<strong>co</strong>vered tree species found only in<br />
KwaZulu-Natal was rec<strong>en</strong>tly published in the South<br />
African Journal of Botany. The tree is a species of<br />
Combretum, popularly known as bushwillows, many<br />
of which are <strong>co</strong>mmon and <strong>co</strong>nspicuous features of<br />
the African bushveld.<br />
The new tree has be<strong>en</strong> named Combretum stylesii,<br />
and is a rare species known so far only from a<br />
rugged, t<strong>en</strong> kilometre stretch of the Tugela River,<br />
within the Maphumulo District Municipality to the<br />
north of Durban. It appears to have be<strong>en</strong> hidd<strong>en</strong> by<br />
its inaccessible habitat, although this is now being<br />
threat<strong>en</strong>ed by road developm<strong>en</strong>t and rural sprawl.<br />
The tree is named after David Styles, a member<br />
of BotSoc KZN Coastal Branch who has <strong>co</strong>llected<br />
several thousand plant specim<strong>en</strong>s in the province<br />
over the past decade, in the process dis<strong>co</strong>vering<br />
a number of other, smaller plant species. David is<br />
editor of the journal published jointly by BotSoc KZN<br />
Coastal Branch and the Durban Botanic Gard<strong>en</strong>s<br />
Trust, PlantLife, and he is founder and administrator<br />
of the Yahoo! discussion group, Plant-chat.<br />
David first found the tree in 2004, but although he<br />
realized that it was an unknown species, both fruits<br />
and flowers were needed in order to <strong>co</strong>mplete its<br />
description. It took four years for this to occur. As<br />
David explains: “the locality is remote and flowering<br />
is brief and erratic. Many visits were made to the<br />
area. In some years no flowers were found or<br />
flowering was just missed.”<br />
Ev<strong>en</strong>tually <strong>co</strong>mplete material was <strong>co</strong>llected and<br />
s<strong>en</strong>t to Olivier Maurin, a Ph.D. stud<strong>en</strong>t studying<br />
the family at the University of Johannesburg, and<br />
Professor A.E. (Braam) <strong>van</strong> Wyk, the r<strong>en</strong>owned plant<br />
taxonomist based at the University of Pretoria.<br />
In addition to more obvious distinguishing features,<br />
bushwillow species can be distinguished from each<br />
other by tiny scales on the leaves that are as unique<br />
as a human fingerprint. The scales of Combretum<br />
stylesii were also stu<strong>die</strong>d under a micros<strong>co</strong>pe and<br />
Marilyn Bodasing<br />
LEAVES & FRUIT of the » Combretum stylesii<br />
its DNA was analyzed, proving its distinctness from<br />
other known species.<br />
The tree grows both on its own and as a vigorous<br />
strangler, climbing up and over other trees. The<br />
vegetation in which it occurs is classified as Eastern<br />
Valley Bushveld and the area is arid and hot with<br />
temperatures oft<strong>en</strong> reaching over 40 degrees<br />
c<strong>en</strong>tigrade in the summer.<br />
Ac<strong>co</strong>rding to David, “It is possible that this new<br />
Combretum occurs at other localities in this area, as<br />
vegetation along this part of the Tugela River is not<br />
well known.” He also believes that more exploration<br />
of this interesting area <strong>co</strong>uld result in other new<br />
dis<strong>co</strong>veries being made.<br />
Combretum stylesii grows easily from seed, and is<br />
curr<strong>en</strong>tly being grown at the Kirst<strong>en</strong>bosch National<br />
Botanical Gard<strong>en</strong>.<br />
Author:<br />
Marilyn Bodasing, University of KwaZulu-Natal<br />
Photo credits:<br />
David Styles<br />
This article was previously published in the September 2011<br />
issue of the Veld & Flora.<br />
Published in the D<strong>en</strong>dron with kind permission of the authors.<br />
Die grootste gedeelte <strong>van</strong> <strong>die</strong> noordoostelike<br />
Springbokvlakte (Limpopo) word onderlê<br />
deur ‘n substraat <strong>van</strong> basaltiese lawa <strong>en</strong> sekondêre<br />
wit kalkste<strong>en</strong>. Van horison tot horison is dié<br />
wêreld plat. Vor<strong>en</strong>toe <strong>en</strong> agtertoe lyk albei ewe<br />
opdraand! Die algehele afwesigheid <strong>van</strong> panne<br />
<strong>en</strong> duidelik gedefinieerde waterlope val ‘n m<strong>en</strong>s<br />
dadelik op. Die waterlope bestaan in werklikheid<br />
uit breë, vlak laagtes wat moeilik met <strong>die</strong> blote oog<br />
waarneembaar is <strong>en</strong> slegs na groot reëns loop. Die<br />
<strong>en</strong>igste afwisseling in <strong>die</strong> gelyk landskap is ‘n breë<br />
strook sand wat <strong>die</strong> noordelike Vlakte <strong>van</strong> <strong>die</strong> suide<br />
skei, <strong>die</strong> sog<strong>en</strong>aamde sandbulte.<br />
Die basalt skep ‘n uitgestrekte, struikagtige,<br />
doringboom-oorheersde bosveld op <strong>die</strong><br />
k<strong>en</strong>merk<strong>en</strong>de basaltiese kleigronde. Groot<br />
gedeeltes is egter al ontbos <strong>en</strong> vir akkerbou<br />
aangew<strong>en</strong>d of deur ander m<strong>en</strong>slike aktiwiteite<br />
getransformeer. Die geoloog, Wagner (1927) het dit<br />
treff<strong>en</strong>d beskryf: “The flats proper are characterized<br />
by their level nature --- the almost <strong>en</strong>tire lack of well<br />
drained water-<strong>co</strong>urses and their peculiar black and<br />
red soils. They are made up of great expanses of<br />
appar<strong>en</strong>tly level grassland and tree steppe --- The<br />
grassland marks the position of the area occupied<br />
by black turf soil. It is normally devoid of trees, but<br />
supports an abundant growth of dwarf bush-like<br />
acacias.”<br />
Die swart turf is ‘n vrugbare, swaar, swakgedreineerde<br />
kleigrond wat in situ ontwikkel het.<br />
Volg<strong>en</strong>s Wagner (1927) is dit ‘n fosfaatryke grond<br />
met sterk rek- <strong>en</strong> krimpei<strong>en</strong>skappe: “The black<br />
turf is a heavy residual clay soil of greyish-black<br />
or bluish-black <strong>co</strong>lour, rich in <strong>co</strong>lloids. It swells<br />
very <strong>co</strong>nsiderably wh<strong>en</strong> wetted and on drying<br />
develops gaping shrinkage cracks which divide<br />
into polygonal (veelhoekige) <strong>co</strong>lumns. Its marked<br />
fertility is due mainly to the high ratio of available<br />
to total phosphorus. The black turf forms a layer<br />
from 1 to 8 feet in thickness, g<strong>en</strong>erally underlain<br />
by nodular calcareous tufa.” Die “<strong>co</strong>lloids” waarna<br />
<strong>die</strong> outeur verwys staan in Afrikaans bek<strong>en</strong>d as<br />
kolloïdale deeltjies; dit is kleiminerale of organiese<br />
deeltjies met ‘n deursnee <strong>van</strong> 0.0005 tot 0.000001<br />
mm wat nie in water oplos nie, maar klein g<strong>en</strong>oeg is<br />
om daarin rond te dryf.<br />
Só ‘n plek is Malgas (154 KS, 2429 AC Zebe<strong>die</strong>la-<br />
Wes), suid <strong>van</strong> Immerpan – ‘n tuiste <strong>van</strong> <strong>die</strong><br />
DIE MAROELABOS VAN TSHIPISE-”DUIN” » Berig op volg<strong>en</strong>de bladsy<br />
DIE INVLOED VAN SWART TURF OP BOOMDIVERSITEIT<br />
Die invloed <strong>van</strong> swart turf op boomdiversiteit<br />
te Malgas, Noordoostelike Springbokvlakte<br />
Ni<strong>co</strong> Hager<br />
review<br />
review<br />
blaasdoring (Acacia luederitzii var. retin<strong>en</strong>s) <strong>en</strong><br />
‘n paar ander wat dié grondsoort se gelyke is.<br />
Die agtervoegsel “-pan” in Immerpan verwys nie<br />
na ‘n pan in <strong>die</strong> werklike sin <strong>van</strong> <strong>die</strong> woord nie.<br />
Volg<strong>en</strong>s Wagner (1927) is daar ge<strong>en</strong> panne op <strong>die</strong><br />
basaltgedeeltes <strong>van</strong> <strong>die</strong> Vlakte nie: “The <strong>co</strong>mplete<br />
abs<strong>en</strong>ce of pans is the more remarkable as they<br />
are fairly <strong>co</strong>mmon on the sand-bults.” ‘n Ondersoek<br />
<strong>van</strong> <strong>die</strong> S.A. 1:50 000 Topo-kadastrale kaarte <strong>van</strong><br />
<strong>die</strong> gebied bevestig inderdaad hul afwesigheid.<br />
Desondanks is daar talle plase op <strong>die</strong> turfvlaktes<br />
met “pan”-name, bv. Klippan (521), Rooipan (508),<br />
Vlakpan (509), Mooipan (519), Turfpan (943),<br />
Zandpan (1048) <strong>en</strong> Kalkpan (127). Immerpan is ‘n<br />
spoorweghalte op Brakfontein (152). Waarskynlik<br />
het hier<strong>die</strong> ou plaasname uit <strong>die</strong> dae <strong>van</strong> <strong>die</strong> ZAR<br />
hul oorsprong in <strong>die</strong> vlak, breë, stadigvloei<strong>en</strong>de<br />
waterlope, wat na groot reëns soos panne lyk.<br />
Nie elke boom wat op ander grondsoorte in <strong>die</strong><br />
omgewing gedy, aard egter op Malgas se swart<br />
turf nie. As voorbeelde, uit <strong>die</strong> omgewing, <strong>van</strong><br />
bome wat glad nie op swart turf kan aanpas nie,<br />
kan <strong>die</strong> vaalboom (Terminalia sericea) <strong>en</strong> <strong>die</strong><br />
wilde-sering (Burkea africana) g<strong>en</strong>oem word.<br />
Hier<strong>die</strong> twee is ware sandliefhebbers. ‘n Boom<br />
se verspreidingspot<strong>en</strong>siaal word beperk as ‘n<br />
lew<strong>en</strong>sbelangrike omgewingsfaktor buite sy<br />
verdraagsaamheidsgr<strong>en</strong>se val, of indi<strong>en</strong> dit sy<br />
vermoë om te kompeteer, strem (Van Wyk, 1982).<br />
In hier<strong>die</strong> geval is <strong>die</strong> grond, <strong>die</strong> swart turf, met sy<br />
besondere chemiese <strong>en</strong> fisiese ei<strong>en</strong>skappe, <strong>die</strong><br />
beperk<strong>en</strong>de faktor.<br />
Tog is daar bome, soos <strong>die</strong> fyndoring (Acacia<br />
t<strong>en</strong>uispina), wat uitsluitlik met swart turf assosieer.<br />
Sulke bome is turfspesialiste. Tuss<strong>en</strong> <strong>die</strong> uiterstes<br />
<strong>van</strong> turfliefhebbers <strong>en</strong> -haters is daar ook <strong>die</strong><br />
veelsydiges (g<strong>en</strong>eraliste) wat op meerdere<br />
grondsoorte deug. As voorbeelde <strong>van</strong> sulke<br />
bome, wat op Malgas voorkom, kan <strong>die</strong> swarthaak<br />
(Acacia mellifera subsp. detin<strong>en</strong>s) <strong>en</strong> witgat (Boscia<br />
albitrunca) g<strong>en</strong>oem word. Dit is gewoonlik bome<br />
met groot verspreidingsgebiede.<br />
Dat <strong>die</strong> swart turf <strong>die</strong> verspreiding <strong>van</strong> verreweg <strong>die</strong><br />
meeste <strong>van</strong> <strong>die</strong> omgewing se bome daarop inhibeer,<br />
word deur <strong>die</strong> feite gestaaf. Op Malgas kom net<br />
16 soorte voor, terwyl daar op Vuurste<strong>en</strong>laagte,<br />
5 kilometer daar<strong>van</strong>daan, op sand, 73 is. Dié<br />
opvall<strong>en</strong>de verskil in diversiteit kan net toegeskryf<br />
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62<br />
FIG 1<br />
Stam <strong>en</strong> bas <strong>van</strong> <strong>die</strong> blasadoring<br />
FIG 3<br />
jong, hang<strong>en</strong>de blaasdoringpeule<br />
FIG 5<br />
Stammetjies, dorings <strong>en</strong> blare <strong>van</strong> <strong>die</strong> fyndoring<br />
FIG 7<br />
Swartstorm<br />
FIG 9<br />
Blomme <strong>van</strong> <strong>die</strong> swartstorm<br />
FIG 2<br />
Normale <strong>en</strong> geswolle dorings <strong>van</strong> <strong>die</strong> blaasdoring<br />
FIG 4<br />
Fyndoring<br />
FIG 6<br />
Hang<strong>en</strong>de fyndoringpeule<br />
FIG 8<br />
Stam <strong>en</strong> bas <strong>van</strong> <strong>die</strong> swartstorm<br />
FIG 10<br />
Veelhoekige kolommetjies in uitgedroogde swart turf<br />
word aan <strong>die</strong> verskil in grondsoort. Alle ander<br />
omgewingsfaktore is immers op so ‘n kort afstand,<br />
oor gelyk grond, e<strong>en</strong> <strong>en</strong> <strong>die</strong>selfde.<br />
Anders as wat ‘n m<strong>en</strong>s intuïtief sou verwag,<br />
onderhou arm sandgronde ‘n veel groter<br />
verskeid<strong>en</strong>heid bome as vrugbare kleigronde.<br />
Vrugbare gronde is hoofsaaklik afkomstig <strong>van</strong><br />
basiese, vulkaniese geste<strong>en</strong>tes (moedermateriaal),<br />
soos basalte, gabbro’s <strong>en</strong> doleriete. Hierte<strong>en</strong>oor<br />
is arm sandgronde, asook windafsettings <strong>van</strong><br />
Kalaharisand, afkomstig <strong>van</strong> sandste<strong>en</strong> (soos<br />
op Vuurste<strong>en</strong>laagte), <strong>en</strong> oppervlaktesand<br />
afkomstig <strong>van</strong> graniete <strong>en</strong> gneise (soos op<br />
<strong>die</strong> Nebo-plato) (Scholes, 1990). Die rede vir<br />
<strong>die</strong> verskil in vrugbaarheid is dat sand, we<strong>en</strong>s<br />
gebrek aan kleiminerale, vinniger dreineer <strong>en</strong><br />
plantvoedingstowwe daardeur uitgeloog word,<br />
terwyl klei stadig dreineer <strong>en</strong> voedingstowwe<br />
behou. In Suid-Afrika onderskei ons gewoonlik<br />
ook tuss<strong>en</strong> plantegroei op voedingstofryke, warm,<br />
laagligg<strong>en</strong>de gronde <strong>en</strong> arm, koeler, hoogligg<strong>en</strong>de<br />
gronde as onderskeidelik soetveld <strong>en</strong> suurveld.<br />
Intermediêre toestande word dan gem<strong>en</strong>gde (bos)<br />
veld g<strong>en</strong>oem.<br />
‘n Tweede verskynsel, wat verbandhou met<br />
grondvrugbaarheid, is dat boombevolkings<br />
op hoërligg<strong>en</strong>de, goed-gedreineerde <strong>en</strong> arm<br />
sandgronde (soos in <strong>die</strong> Waterberg) breëblaargedomineerd<br />
is (veral lede <strong>van</strong> <strong>die</strong> Combretaceae<br />
<strong>en</strong> Caesalpiniaceae), terwyl bevolkings op<br />
laagligg<strong>en</strong>de, swak-gedreineerde, vrugbare <strong>en</strong><br />
kalkryke kleigronde (soos op <strong>die</strong> Springbokvlakte)<br />
mikrofillies of fynblaar-gedomineerd is (veral lede<br />
<strong>van</strong> <strong>die</strong> Mimosaceae) (Scholes, 1990; Coetzee e.a.,<br />
1977). Selfs <strong>die</strong> bome se verdedigingstrategieë<br />
te<strong>en</strong> blaarvreters volg min of meer <strong>die</strong><br />
grondvrugbaarheidspatrone <strong>van</strong> <strong>die</strong> bosveld:<br />
chemies (tanni<strong>en</strong>) op arm gronde; struktureel<br />
(dorings) op vrugbare gronde (Scholes, 1990).<br />
Die voor <strong>die</strong> hand ligg<strong>en</strong>de vraag is wat <strong>die</strong> rede(s)<br />
vir dié ”ei<strong>en</strong>aardige” verspreidingsgedrag <strong>van</strong> <strong>die</strong><br />
bome is? Hoewel <strong>die</strong> verskil in boomdiversiteit<br />
tuss<strong>en</strong> klei- <strong>en</strong> sandgronde welbek<strong>en</strong>d is, is daar<br />
nogtans min daaroor gepubliseer. Volg<strong>en</strong>s <strong>die</strong><br />
beskikbare literatuur oor <strong>die</strong> onderwerp berus dit<br />
egter bloot op <strong>die</strong> bome se natuurlike reaksies op<br />
gegewe omgewingsfaktore.<br />
Soos reeds g<strong>en</strong>oem, p<strong>en</strong>etreer <strong>en</strong> filtreer water<br />
maklik deur sand. Hierte<strong>en</strong>oor absorbeer klei water<br />
stadig, wat waterverlies deur afvloei <strong>en</strong> verdamping<br />
meebring (Scholes, 1990). Plantvoedingstowwe<br />
word op dié wyse maklik uitgeloog in sand,<br />
maar bly behoue in klei. Daarom is kleigronde,<br />
DIE INVLOED VAN SWART TURF OP BOOMDIVERSITEIT<br />
review<br />
review<br />
soos <strong>die</strong> swart turf <strong>van</strong> <strong>die</strong> Springbokvlakte, baie<br />
vrugbaar. Hoewel klei vog vir lang tye behou, kan<br />
boomwortels dit nie maklik opneem nie omdat <strong>die</strong><br />
water stewig aan <strong>die</strong> kleideeltjies vaskleef. Bome<br />
op kleigronde verkry nietemin steeds g<strong>en</strong>oeg<br />
voedingstowwe, danksy <strong>die</strong> vrugbaarheid <strong>van</strong> <strong>die</strong><br />
grond. Bome op sandgronde moet egter groter<br />
hoeveelhede water absorbeer om in hul minerale<br />
voedingstofbehoeftes te voorsi<strong>en</strong>. Om dan weer<br />
<strong>van</strong> <strong>die</strong> oortollige water ontslae te raak, het hulle<br />
(in <strong>die</strong> algeme<strong>en</strong>) breë (groot) blare om vinniger<br />
te kan transpireer, terwyl bome op kleigronde<br />
eerder <strong>die</strong> skaars water moet bespaar <strong>en</strong> daarom<br />
klein blaartjies het (Grant & Thomas, 2000). Bome<br />
is dus aangepas by hul natuurlike omgewings om<br />
dit t<strong>en</strong> beste te b<strong>en</strong>ut.<br />
Dit verduidelik natuurlik nog nie wat <strong>die</strong><br />
“verdwerging” <strong>van</strong> <strong>die</strong> bome op <strong>die</strong> swart turf<br />
<strong>van</strong> <strong>die</strong> Springbokvlakte, in weerwil <strong>van</strong> hul<br />
veelgeroemde vrugbaarheid, veroorsaak nie. Wat<br />
gebeur, is dat <strong>die</strong> rek- <strong>en</strong> krimpbewegings <strong>van</strong> <strong>die</strong><br />
klei, in reaksie op b<strong>en</strong>atting <strong>en</strong> uitdroging, <strong>die</strong> bome<br />
se wortels beskadig. Die skade wat hier<strong>die</strong> ei<strong>en</strong>skap<br />
<strong>van</strong> turf aan m<strong>en</strong>sgemaakte strukture kan aanrig, is<br />
welbek<strong>en</strong>d. Die pot<strong>en</strong>siële uitsetting (<strong>en</strong> inkrimping)<br />
<strong>van</strong> turf wissel <strong>van</strong> plek tot plek, afhang<strong>en</strong>de <strong>van</strong><br />
faktore soos grond<strong>die</strong>pte, maar kan baie groot wees.<br />
Wagner (1927) het dit bloot as “very <strong>co</strong>nsiderable”<br />
beskryf. Te oordeel aan <strong>die</strong> “golwe” wat ‘n m<strong>en</strong>s<br />
soms op teerpaaie wat op turf gebou is, si<strong>en</strong> (bv. op<br />
<strong>die</strong> Roedtan-Potgietersruspad), kan dit aansi<strong>en</strong>lik<br />
wees. Volg<strong>en</strong>s Van der Merwe (1964) is opwellings<br />
(heaves) <strong>van</strong> 80–100 mm algeme<strong>en</strong> vir swart turf,<br />
maar vertikale bewegings <strong>van</strong> meer as 300 mm is<br />
moontlik <strong>en</strong> op Lethabo is opwellings <strong>van</strong> meer as<br />
500 mm op alluviale gronde aangetek<strong>en</strong>. Dit verg<br />
dus ge<strong>en</strong> besonderse verbeelding om ‘n begrip te<br />
vorm <strong>van</strong> <strong>die</strong> kragte waaraan boomwortels, veral<br />
haarwortels, in swart turf blootgestel is nie. ‘n M<strong>en</strong>s<br />
kan maar sê hulle word voortdur<strong>en</strong>d “gesnoei”. Die<br />
gevolg is ‘n natuurlike verdwergde groeivorm, net<br />
soos wat <strong>die</strong> kunsmatige snoei <strong>van</strong> wortels ook deur<br />
<strong>die</strong> m<strong>en</strong>s gebruik word om bonsai-plante te skep.<br />
Dit hang dus waarskynlik <strong>van</strong> ‘n boom se<br />
lew<strong>en</strong>skragtigheid <strong>en</strong> herstelvermoë af of dit<br />
<strong>die</strong> mas op swart turf, soos <strong>die</strong> <strong>van</strong> Malgas, sal<br />
opkom of nie. Weinig beskik blykbaar oor dié<br />
vermoëns. Bome wat dit wel het of selfs turf bo<br />
ander grondsoorte verkies, is soos gemeld,<br />
turfspesialiste. Net twee <strong>van</strong> Malgas se bome<br />
kan beskou word as egte turfspesialiste: <strong>die</strong><br />
blaasdoring <strong>en</strong> <strong>die</strong> fyndoring. Die ander si<strong>en</strong> ‘n<br />
m<strong>en</strong>s ook in gem<strong>en</strong>gde bosveld <strong>en</strong> op sand, selfs<br />
63<br />
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64<br />
review<br />
review<br />
DIE INVLOED VAN SWART TURF OP BOOMDIVERSITEIT<br />
Kalaharisand (bv. swarthaak). Dit is nie duidelik<br />
waarom turfspesialiste nie op sandgronde vestig nie.<br />
E<strong>en</strong> moontlikheid is dat <strong>die</strong> bome swak met ander<br />
bome kompeteer <strong>en</strong> daarom <strong>die</strong> gespesialiseerde<br />
turfhabitat (waarby min bome aangepas is) verkies.<br />
Ongeveer 80 uit elke 100 bome op Malgas<br />
is ‘n blaasdoring. Vir hom betek<strong>en</strong> <strong>die</strong> swart<br />
turf <strong>die</strong> lewe. Die blaasdoring is meestal ‘n<br />
laagvertakk<strong>en</strong>de, meerstammige haakbos met kort,<br />
gepaarde haakdorings <strong>en</strong> <strong>en</strong>kele groot, wit, reguit,<br />
opgeblaasde dorings, amper soos <strong>die</strong> dorings<br />
wat ‘n m<strong>en</strong>s soms aan <strong>die</strong> Nataldoring (Acacia<br />
natalitia) si<strong>en</strong>, net korter. Die oningewyde si<strong>en</strong> hom<br />
maklik vir iets anders aan, totdat <strong>die</strong> onverwagte<br />
aanskoue <strong>van</strong> <strong>die</strong> bolmagie-dorings, saam met<br />
<strong>die</strong> “normales” aan e<strong>en</strong> <strong>en</strong> <strong>die</strong>selfde tak, sy ware<br />
id<strong>en</strong>titeit met verbasing tuisbring. Soms ontbreek<br />
<strong>die</strong> grootdorings geheel <strong>en</strong> al, veral by ouer bome.<br />
Laasg<strong>en</strong>oemde eksemplare is <strong>en</strong>kelstammig <strong>en</strong> tot<br />
7 m hoog.<br />
Volg<strong>en</strong>s Ross (1979, p. 12) is <strong>die</strong> geswolle dorings<br />
nie insekgalle nie, maar ‘n normale produk <strong>van</strong><br />
<strong>die</strong> boom self. Wipstertmiere maak egter soms<br />
nes in <strong>die</strong> dorings <strong>en</strong> is na bewering vir <strong>die</strong><br />
boom tot nut. Die blaasdoring se tweelingbroer,<br />
<strong>die</strong> Kalaharidoring (Acacia luederitzii var.<br />
luederitzii), wat nie opgeblaasde dorings het nie,<br />
verkies uitsluitlik <strong>die</strong> Kalahari se sand, met net ‘n<br />
beperkte verspreiding duskant <strong>die</strong> suidoostelike<br />
Botswanagr<strong>en</strong>s (steeds op Kalaharisand). Die feit<br />
dat dié grootboet Kalaharisand, in te<strong>en</strong>stelling met<br />
turf verkies, laat ‘n m<strong>en</strong>s wonder of <strong>die</strong> twee werklik<br />
net variëteite of selfs subspesies is <strong>en</strong> nie eerder<br />
volwaardige afsonderlike spesies is nie?<br />
‘n Yl, lang <strong>en</strong> fyndoringrige struikie, wat uitsluitlik<br />
op swart turf tuis is, is <strong>die</strong> fyndoring. E<strong>en</strong> <strong>van</strong><br />
sy ander name is inderdaad turfdoring. Hier<strong>die</strong><br />
kleintjie is ‘n ware turfliefhebber <strong>en</strong> jy sal hom nie<br />
kry, t<strong>en</strong>sy jy hom op swart turf soek nie. Op Malgas<br />
staan dit plek-plek op versteurde grond so dig dat<br />
dit <strong>van</strong> stap ‘n beproewing maak. Die fyndoring is<br />
<strong>die</strong> <strong>en</strong>igste plant, behalwe <strong>die</strong> <strong>en</strong>kele kanferbos<br />
(Tarchonanthus camphoratus) hier <strong>en</strong> daar, wat<br />
op <strong>die</strong> hope bogrond <strong>van</strong> <strong>die</strong> ongerehabiliteerde<br />
Malgasse kalkgroewe <strong>van</strong> weleer floreer.<br />
Dié meerstammige doringboompie (meer struik as<br />
boom) spruit <strong>van</strong>uit ‘n meerjarige, ondergrondse<br />
wortelstelsel (Palgrave, 2002) met gladde, persbruin<br />
stammetjies so dik soos ‘n potlood of jou vinger. Dit<br />
kan ‘n meter of twee hoog word. Ou stammetjies<br />
gaan lê later almal na <strong>die</strong> e<strong>en</strong> kant toe soos iets<br />
wat geswik het <strong>en</strong> gaan dan dood. Soos <strong>die</strong> naam<br />
sê, is <strong>die</strong> dorings lank <strong>en</strong> fyn (dun) <strong>en</strong> wys terug<br />
na <strong>die</strong> hoofstamme. Die blomme is in digte eiergeel<br />
bolletjies gerangskik. Die klewerige peule is kort,<br />
plat, geboë <strong>en</strong> oortrek met swart kliertjies. Op ‘n<br />
afstand kan hy jou moontlik mislei om hom aan te<br />
si<strong>en</strong> vir ‘n plaat jong soetdorings (Acacia karroo),<br />
maar <strong>van</strong> naderby is <strong>die</strong> verskille baie duidelik.<br />
Byvoorbeeld, <strong>die</strong> soetdoring se peule is nie<br />
klewerig nie <strong>en</strong> sonder <strong>die</strong> swart kliertjies. Omdat<br />
<strong>die</strong> fyndoring so punt<strong>en</strong>erig is oor <strong>die</strong> tipe grond<br />
loop m<strong>en</strong>se soms ‘n leeftyd lank in <strong>die</strong> veld rond<br />
sonder om hom ooit te k<strong>en</strong>.<br />
E<strong>en</strong> <strong>van</strong> Malgas se struike wat dikwels met <strong>die</strong>p,<br />
swaar kleigronde geassosieer is, maar nie werklik<br />
‘n getroue turfliefhebber is nie, is <strong>die</strong> swartstorm<br />
(Cadaba aphylla), want hy het twee liefdes --- turf<br />
én kalkste<strong>en</strong>. Elders in Suid-Afrika si<strong>en</strong> ‘n m<strong>en</strong>s dit<br />
dikwels in nate <strong>en</strong> skeure <strong>van</strong> kaal kalkste<strong>en</strong>kranse<br />
(bv. op <strong>die</strong> Ghaapse plato). Die vraag is nou of hy<br />
op <strong>die</strong> Springbokvlakte se turfvlaktes tuis is oor <strong>die</strong><br />
hondjie of <strong>die</strong> halsbandjie, <strong>die</strong> turf of <strong>die</strong> kalk? T<strong>en</strong><br />
spyte <strong>van</strong> sy groot verspreidingsgebied is hy tog nie<br />
orals te vinde nie as gevolg <strong>van</strong> sy sterk voorkeure<br />
vir grondtipe.<br />
Soos <strong>die</strong> spesifieke naam aphylla aandui, is <strong>die</strong><br />
plant blaarloos, behalwe in saailinge of aan baie<br />
jong takkies. Die algem<strong>en</strong>e voorkoms is <strong>die</strong> <strong>van</strong> ‘n<br />
slordige, stekelrige bos wat ietwat aan ‘n ystervark<br />
herinner. Die takkies is blougro<strong>en</strong>; <strong>die</strong> blommetjies<br />
pragtig rooi met <strong>die</strong> meeldrade op <strong>die</strong> punt <strong>van</strong> ‘n<br />
lang steeltjie <strong>en</strong> <strong>die</strong> vruggies wurmagtig, amper<br />
soos <strong>die</strong> knoppiesboontjie (Maerua angol<strong>en</strong>sis) s’n,<br />
net kleiner. Aan<strong>van</strong>klik staan of lê hy op <strong>die</strong> grond,<br />
maar ouer plante het plat, swart stamme waarmee<br />
hulle in bome oprank of opleun <strong>en</strong> wat soos ‘n<br />
bobbejaan se arm lyk, kompleet met skielike, skerp<br />
buig <strong>en</strong> al, nes ‘n elmboog. Vandaar <strong>die</strong> paslike<br />
alternatiewe volksnaam, bobbejaanarm.<br />
Enige<strong>en</strong> wat ‘n aftrekstel <strong>van</strong> <strong>die</strong> swartstorm se wortel<br />
as purgeermiddel ingekry het, staar na bewering ‘n<br />
moeilike tyd in <strong>die</strong> gesig! Hier<strong>die</strong> ekstremiteit was<br />
ook <strong>die</strong> aanleiding tot <strong>die</strong> uitsonderlike naam: “The<br />
vernacular name is an allusion to the black <strong>co</strong>lour<br />
of the bark of the root and the “stormy” action of<br />
the bark in de<strong>co</strong>tions wh<strong>en</strong> tak<strong>en</strong> as a purgative.”<br />
(Smith, 1966).<br />
Behalwe voormelde drie soorte kom <strong>die</strong> volg<strong>en</strong>de<br />
bome <strong>en</strong> groter struike ook op Malgas se swart turf<br />
voor:<br />
Boscia albitrunca;<br />
B. foetida subsp. rehmanniana;<br />
Acacia karroo;<br />
A. mellifera subsp. detin<strong>en</strong>s;<br />
A. tortillis subsp. heteracantha;<br />
Searsia <strong>en</strong>gleri;<br />
S. pyroides;<br />
Ziziphus mucronata;<br />
Grewia flava;<br />
Combretum herero<strong>en</strong>se subsp. herero<strong>en</strong>se var.<br />
herero<strong>en</strong>se;<br />
Euclea undulata;<br />
Ehretia rigida subsp. nervifolia; <strong>en</strong><br />
Tarchonanthus camphoratus.<br />
Dit sou onvolledig wees om nie ook <strong>van</strong> <strong>die</strong><br />
dominante grasse te vermeld nie, want <strong>die</strong> Vlakte se<br />
swart turf is graswêreld. Die gras wat Wagner (1927)<br />
so geïmponeer het, is waarskynlik witbuffelsgras<br />
(Panicum <strong>co</strong>loratum var. <strong>co</strong>loratum). Ook dit groei<br />
by voorkeur op swaar, vrugbare gronde (Van<br />
Oudtshoorn, 1994). ‘n Bees wat daarop loop, word<br />
spekvet (pers. med. mnr. J.S. V<strong>en</strong>ter).<br />
T<strong>en</strong> spyte <strong>van</strong> <strong>die</strong> beperkte boomverskeid<strong>en</strong>heid<br />
is <strong>die</strong> veld op <strong>die</strong> swart turfvlaktes <strong>van</strong> <strong>die</strong><br />
Springbokvlakte uit ‘n boerdery oogpunt alles<br />
behalwe minderwaardig vergeleke by ander<br />
veldtipes <strong>van</strong> <strong>die</strong> Bosveld. Die veld is soet, <strong>die</strong> grond<br />
vrugbaar, <strong>die</strong> drakrag hoog <strong>en</strong> <strong>die</strong> plek het sy eie<br />
bekoring <strong>en</strong> mistiek. En as jy nog nie <strong>die</strong> blaas- of<br />
fyndoring gesi<strong>en</strong> het nie, soek hulle gerus op <strong>die</strong><br />
swart turfvlaktes <strong>van</strong> <strong>die</strong> Springbokvlakte op plekke<br />
soos Malgas.<br />
FOTOS:<br />
Mnr. Dick Duncan<br />
ERKENNINGS:<br />
Dank is verskuldig aan mnr. Koos V<strong>en</strong>ter vir <strong>die</strong><br />
beskikbaarstelling <strong>van</strong> sy fasiliteite; aan dr. Phil Paige-Gre<strong>en</strong><br />
<strong>van</strong> <strong>die</strong> WNNR <strong>en</strong> mnr. Peter Day <strong>van</strong> Jones & Wag<strong>en</strong>er vir<br />
DIE INVLOED VAN SWART TURF OP BOOMDIVERSITEIT<br />
review<br />
review<br />
inligting; aan prof. S.W. Ja<strong>co</strong>bsz <strong>van</strong> UP vir <strong>die</strong> verkryging<br />
<strong>van</strong> ‘n literatuurbron; <strong>en</strong> aan prof. Braam <strong>van</strong> Wyk <strong>van</strong> UP vir<br />
aanmoediging om <strong>die</strong> artikel te skryf, vir inligting <strong>en</strong> vir <strong>die</strong><br />
kontrolering <strong>van</strong> <strong>die</strong> manuskrip.<br />
BRONNELYS:<br />
1. COETZEE, B.J., VAN DER MEULEN, F., ZWANZIGER, S.,<br />
GONSALVES, P. & WEISSER, P.J. 1977. A phytosociological<br />
classification of the Nylsvley Nature Reserve. CSIR,<br />
Pretoria.<br />
2. GRANT, R. & THOMAS, V. 2002. Sappi tree spotting<br />
Bushveld. Jacana Education Ltd, Johannesburg.<br />
3. PALGRAVE, M.C. 2002. Trees of Southern Africa, Third<br />
edition. Struik Publishers, Cape Town.<br />
4. ROSS, J.H. 1979. A <strong>co</strong>nspectus of the African Acacia<br />
species. Memoirs of the Botanical Survey of South Africa.<br />
Botanical Research Institute, Pretoria.<br />
5. SCHOLES, R.J. 1990. The influ<strong>en</strong>ce of soil fertility on the<br />
e<strong>co</strong>logy of Southern African dry sa<strong>van</strong>nas. Journal of<br />
Biogeography 17 (4/5): 415–419.<br />
6. SMITH, C.A. 1966. Common names of South African<br />
plants. Governm<strong>en</strong>t Printer, Pretoria.<br />
7. VAN DER MERWE, D.H. 1964. The prediction of heave<br />
from the plasticity index and perc<strong>en</strong>tage clay fraction<br />
in soils. The Civil Engineer in South Africa, June 1964:<br />
103–107.<br />
8. VAN OUDTSHOORN, F.P. 1994. Gids tot grasse <strong>van</strong> Suid-<br />
Afrika. Bri<strong>za</strong> Publikasies, Arcadia, Pretoria.<br />
9. VAN WYK, A.E. 1982. Seldsame Bome –<br />
10.<br />
Verspreidingsfaktore, D<strong>en</strong>drologiese Tydskrif 2 (1 & 2):<br />
3 – 24.<br />
WAGNER, P.A. 1927. The geology of the north-eastern<br />
part of the Springbok Flats and surrounding <strong>co</strong>untry.<br />
Geological Survey. Governm<strong>en</strong>t Printer, Pretoria.<br />
65<br />
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WHITE PEAR Apodytes dimidiata » Foto: Naas Grové<br />
STINKWOOD o<strong>co</strong>tea bullata » Photo: Naas Grové<br />
group of 26 members of the Out<strong>en</strong>iqua<br />
A branch of the D<strong>en</strong>drological Society and<br />
two members of the fledgling Worcester section<br />
visited Grootvadersbos over the week<strong>en</strong>d of 10-11<br />
September, 2011. We were ably guided by Pierre<br />
<strong>van</strong> d<strong>en</strong> Berg (ex Cape Nature) and the extremely<br />
<strong>co</strong>mpet<strong>en</strong>t and amiable Goliath Highburg, a serving<br />
Field Ranger at Cape Nature, known affectionately<br />
as “Twakkies”. The forest repres<strong>en</strong>ts the southwestern<br />
most vestige of Afromontane forest which<br />
had earlier occupied vast areas of the southern<br />
Cape. Grootvadersbos had mercifully be<strong>en</strong> spared<br />
the most severe fires and more importantly, the<br />
insatiable woodcutters’ axes. Secure from utter<br />
devastation from the harvesters, partially on ac<strong>co</strong>unt<br />
of its inaccessibility and the fact that it <strong>co</strong>uld re<strong>co</strong>ver<br />
from exploitation owing to its good rainfall, seclusion<br />
in a deep kloof where soil is fertile and fires do not<br />
p<strong>en</strong>etrate so easily, the forest has survived and<br />
matured to reveal some excell<strong>en</strong>t examples of<br />
some of the southern Cape’s signal Afromontane<br />
species. Control measures undertak<strong>en</strong> at first by<br />
the Departm<strong>en</strong>t of Forestry and later Cape Nature<br />
have meant the forest is now in good hands and<br />
thriving.<br />
Of the official list of 46 <strong>co</strong>mmon tree species<br />
which can be found in the forest, the group had the<br />
opportunity of viewing 34 at close range.<br />
A key species in the forest is Olea cap<strong>en</strong>sis subsp.<br />
macrocarpa (Ironwood). This species is abundantly<br />
evid<strong>en</strong>t throughout the forest and the towering size<br />
of the specim<strong>en</strong>s viewed, left the group with little<br />
more than a good feeling for the greyish bark with<br />
its ind<strong>en</strong>tations, an occasional “cro<strong>co</strong>dile skin-like”<br />
appearance and sporadic black “oozes”, which seem<br />
to occur anywhere on the trees, but more particularly<br />
where a wound has occurred in the bark.<br />
Notable of the species found in the forest are the<br />
various “pear” species. These trees are notoriously<br />
difficult to separate, but the group <strong>co</strong>uld get a<br />
true feel for the subtle differ<strong>en</strong>ces betwe<strong>en</strong> these<br />
species. To start with, Olinia v<strong>en</strong>tosa (Hard Pear)<br />
was in full flower with small posies of yellow<br />
flowerets (similar to the smaller clusters of flowers<br />
on the Cherry/Candlewoods which were also in<br />
flower). The bark was shown to be reddish-brown<br />
and deeply fissured l<strong>en</strong>gthways. In <strong>co</strong>ntrast Scalopia<br />
bye<strong>en</strong>komste<br />
ev<strong>en</strong>ts<br />
Grootvadersbos excursion<br />
Robert Smith - September, Grootvadersbos<br />
mundii, (Red Pear) was pointed out on a number of<br />
occasions. Many of these trees have survived to<br />
be<strong>co</strong>me excell<strong>en</strong>t soaring canopy specim<strong>en</strong>s; not<br />
the “small to medium sized” trees which the field<br />
guides would have you believe. On ac<strong>co</strong>unt of their<br />
cathedral-like growth, the stems have a definitive<br />
smooth but mostly blistering bark structure,<br />
where the blisters hang downwards and not in<br />
any direction as in Podacarpus falcatus (Out<strong>en</strong>iqua<br />
Yellowwood). More oft<strong>en</strong> than not, while marvelling<br />
at the various specim<strong>en</strong>s in this forest of superb tall<br />
canopy trees, the bark and stems are all one has to<br />
go by to determine the species! Alas, no specim<strong>en</strong>s<br />
of Apodites dimidiata (White pear) <strong>co</strong>uld be found.<br />
On the south facing slopes of the forest, good<br />
sightings of Cunonia cap<strong>en</strong>sis (Red Alder) <strong>co</strong>uld<br />
be had. Some of these specim<strong>en</strong>s were truly awe<br />
inspiring. One in particular was situated near the<br />
canopy bird hide and its pres<strong>en</strong>ce alongside a<br />
marvellous example of a <strong>co</strong>ppiced O<strong>co</strong>tea bullata<br />
(Stinkwood) which had s<strong>en</strong>t up its rescue shoots<br />
to the canopy in defiance of the otherwise mortal<br />
wound which it had suffered sometime in its troubled<br />
past, left one with a true s<strong>en</strong>se of amazem<strong>en</strong>t at these<br />
spectacular trees. This canopy is also shared with<br />
a number of introduced California Redwoods and<br />
together with Podocarpus falcatus and Podocarpus<br />
latifolious (Out<strong>en</strong>iqua and Real Yellowwood) one<br />
has a magnific<strong>en</strong>t feeling for this great forest. The<br />
haunting song of Narina trogons (two people were<br />
lucky <strong>en</strong>ough to see one) and the fleeting twitters<br />
of Cape White-eyes, Greater Double-<strong>co</strong>llared<br />
Sunbirds and Blue-mantled Crested Flycatchers,<br />
seem to bear out the fact that the area is well<br />
appreciated by the locals!<br />
While it would be impossible to m<strong>en</strong>tion all species<br />
<strong>en</strong><strong>co</strong>untered in this forest, it is with <strong>co</strong>nviction that<br />
one can say that the visit was well worth the effort<br />
and every hope is that it will <strong>co</strong>ntinue to survive and<br />
grow under the ongoing care and dedication of the<br />
officials of Cape Nature.<br />
The group would like to re<strong>co</strong>rd their appreciation<br />
of the excell<strong>en</strong>t <strong>co</strong>ttage facilities on Honeywood<br />
farm run by Miranda and John Moo<strong>die</strong> next door to<br />
Grootvadersbos.<br />
67<br />
DENDRON » No/Nr: 43 » November 2011
DENDRON » No/Nr: 43 » November 2011<br />
68<br />
bye<strong>en</strong>komste<br />
ev<strong>en</strong>ts<br />
BIG TREE COMPETITION 2011<br />
Grootboommeet-kompetisie<br />
in samewerking met RSG<br />
Redakteur - nam<strong>en</strong>s <strong>die</strong> S<strong>en</strong>trale Komitee<br />
Ons het ‘n wonderlike reaksie gehad deur oor <strong>die</strong> 70 inskrywings vir <strong>die</strong> eerste Grootboommeet-kompetisie<br />
te ont<strong>van</strong>g. Ons het <strong>die</strong> voorreg gehad om saam met RSG lugtyd te kry om <strong>die</strong> nuus te verspei <strong>en</strong> so ook<br />
bewustheid oor <strong>die</strong> D<strong>en</strong>drologiese Ver<strong>en</strong>iging <strong>en</strong> sy missie aan te spoor.<br />
Daar was twee kategorieë om <strong>van</strong> te kies tyd<strong>en</strong>s <strong>die</strong> boommeet kompetisie. Die eerste kategorie was vir <strong>die</strong> meet<br />
<strong>en</strong> opname <strong>van</strong> groot bome met <strong>die</strong> grootste stamomtrek op borshoogte. Vir hiér<strong>die</strong> kategorie kon drie w<strong>en</strong>ners<br />
elk ‘n kopie, getek<strong>en</strong> deur <strong>die</strong> outeurs <strong>van</strong> Dictionary of Names of South African Trees (Prof AB <strong>van</strong> Wyk, Dr Erika<br />
<strong>van</strong> d<strong>en</strong> Berg, Meg Coates-Palgrave & Marie Jordaan, 2011. BRIZA, PLUS ) ont<strong>van</strong>g, asook ‘n uitgawe <strong>van</strong> Gre<strong>en</strong><br />
heritage: trees, forests and woodlands of South Africa (Departm<strong>en</strong>t of Agriculture, Forestry & Fisheries, 2011).<br />
Die tweede kategorie was vir <strong>die</strong> meet <strong>en</strong> opname <strong>van</strong> uitsonderlike bome. Ti<strong>en</strong> w<strong>en</strong>ners kon elk ’n kopie<br />
<strong>van</strong> Field Guide to Trees of Southern Africa (Prof. Braam <strong>van</strong> Wyk & Piet <strong>van</strong> Wyk. 1997, Struik Publishers, Cape<br />
Town PLUS) asook ‘n uitgawe <strong>van</strong> Gre<strong>en</strong> heritage: trees, forests and woodlands of South Africa (Departm<strong>en</strong>t of<br />
Agriculture, Forestry & Fisheries, 2011) ont<strong>van</strong>g.<br />
Kategorie 1<br />
Groot bome met <strong>die</strong> grootste stamomtrek op borshoogte<br />
Eerste Prys:<br />
Dr. Fran<strong>co</strong>is du Randt <strong>van</strong> Hluhluwe in Kwa-Zulu Natal het nie minder nie as 33 spesies opgemeet. Wat hier<strong>die</strong><br />
bydrae besonder maak is dat hy oor ongeveer 23 jaar <strong>die</strong> groei patroon <strong>van</strong> onder andere talle voorbeelde<br />
<strong>van</strong> <strong>die</strong> Newtonia hildebrandtii var. hildebrandtii (Lebombo-wattel, <strong>en</strong>demies aan <strong>die</strong> streek) opgemeet <strong>en</strong><br />
gedokum<strong>en</strong>teer het. Hy het <strong>die</strong> volledige lys <strong>van</strong> bome wat hy opgemeet het aan <strong>die</strong> Ver<strong>en</strong>iging beskikbaar<br />
gestel sodat dit in <strong>die</strong> Nasionale Register <strong>van</strong> Grootbome in Suid-Afrika opg<strong>en</strong>eem kan word. Twee <strong>van</strong> <strong>die</strong><br />
grootste Lebombo-wattels wat hy opgemeet het se stamomtrek by borshoogte is onderskeidelik 8,80m <strong>en</strong> 7,40m.<br />
Interessante afleidings wat hy <strong>die</strong> afgelope 23 jaar gemaak het sluit in <strong>en</strong> ek haal hom aan:<br />
Die Lebombo-wattel bome<br />
begin krimp voordat hulle doodgaan.Die bome groei nie eweredig oor <strong>die</strong> jare<br />
nie – dit het waarskynlik te do<strong>en</strong> met <strong>die</strong> wissel<strong>en</strong>de reënval. Ons kan aflei, mits <strong>die</strong><br />
bome eweredig gegroei het dat hulle maklik tuss<strong>en</strong> 500 <strong>en</strong> 800 jaar oud kan wees.<br />
Ekstrapoleer hier<strong>die</strong> inligting op ‘n grafiek <strong>en</strong> kyk na <strong>die</strong> afleidings! Dit lyk amper asof<br />
<strong>die</strong> gemiddelde Newtonia spp ongeveer 0,5 cm per jaar dikker word, maar natuurlik<br />
is daar ‘n hordes ander faktore, soos hoogte <strong>van</strong> <strong>die</strong> boom, <strong>en</strong> so meer.<br />
Tweede Prys:<br />
Mnr. Chris jordaan <strong>van</strong> K<strong>en</strong>hardt wat vir ons ‘n baie interessante opmeting <strong>van</strong> ‘n Acacia erioloba (kameeldoring)<br />
met 6 stamme ingestuur het. Die boom het ‘n baie groot basis wat op 1 – 1,2m vertak. Chris het al <strong>die</strong> stamme by<br />
1,4m kon opmeet. Hy laat weet ook dat ‘n kleinerige t<strong>en</strong>t opgeslaan kan word tuss<strong>en</strong> <strong>die</strong> stamme bo-op <strong>die</strong> basis<br />
<strong>van</strong> <strong>die</strong> boom. Die gesam<strong>en</strong>tlike omtrek <strong>van</strong> <strong>die</strong> ses stamme is 13,6m!<br />
Derde Prys:<br />
Me. Linda Retief <strong>van</strong> Smithfield wat ‘n Olea europaea subsp. africana (oli<strong>en</strong>hout) met 14 stamme opgemeet het.<br />
Die totale stamomtrek by borshoogte is ‘n allemintige 10,15m.<br />
Kategorie 2<br />
Uitsonderlike bome opgemeet<br />
1<br />
2<br />
3<br />
4<br />
5<br />
6<br />
7<br />
8<br />
9<br />
10<br />
BIG TREE COMPETITION 2011<br />
Mnr. Wynand Breyt<strong>en</strong>bach <strong>van</strong> Montanapark het ‘n Diospyros mespiliformis (jakkalsbessie) met ‘n<br />
stamomtrek <strong>van</strong> 6,34m opgemeet.<br />
Mnr. Gideon Od<strong>en</strong>daal <strong>van</strong> Polokwane het ‘n twee-stam Boscia albitunca (witgat) met ‘n stamomtrek<br />
<strong>van</strong> 4,06m opgemeet.<br />
Mnr. Deon d<strong>en</strong> Hartog <strong>van</strong> Die Boord, Stell<strong>en</strong>bosh het ‘n Erythrina caffra (Kaapse koraalboom)<br />
met ‘n stamomtrek <strong>van</strong> 4,91m opgemeet.<br />
Mnr. Carel Erasmus <strong>van</strong> Stell<strong>en</strong>bosh het ‘n Mayt<strong>en</strong>us oleoides (klip-kershout) met vier stamme<br />
opgemeet. Die gesam<strong>en</strong>tlike stamomtrek by borshoogte is 8,9m.<br />
Me. Lisa Martus <strong>van</strong> Ha<strong>en</strong>ertsburg het ‘n Cussonia spicata (kiepersol) met ‘n stamomtrek <strong>van</strong><br />
9,65m opgemeet.<br />
Me. Ronel Ekste<strong>en</strong> <strong>van</strong> Mookgophong het ‘n Searsia lancea (karee) met ‘n stamomtrek <strong>van</strong> 6.69m<br />
opgemeet.<br />
Gl<strong>en</strong>wood House School in George het as skoolprojek 6 bome opgemeet. Dit is <strong>die</strong> <strong>en</strong>igste skool<br />
wat ingeskryf het <strong>en</strong> omdat ons juis <strong>die</strong> liefde <strong>en</strong> k<strong>en</strong>nis <strong>van</strong> bome onder <strong>die</strong> jeug wil bevorder, is hulle<br />
ook w<strong>en</strong>ners.<br />
Mnr. Willem <strong>van</strong> jaarsveld <strong>van</strong> Annlin het ‘n Dovyalis zeyheri (wilde-appelkoos) met ‘n stamomtrek<br />
<strong>van</strong> 2,94m opgemeet.<br />
Mnr. Kambro Swanepoel <strong>van</strong> Oudtshoorn het ‘n Ficus burkei (gewone wildevy) met ‘n stamomtrek<br />
<strong>van</strong> 9,55m opgemeet<br />
Mnr. Gerbie Strydom <strong>van</strong> Baltimore het ‘n Acacia erioloba (kameeldoring) met ‘n stamomtrek <strong>van</strong> 4,25m<br />
opgemeet. Hier<strong>die</strong> is waarskylik <strong>die</strong> grootste kameeldoringboom in <strong>die</strong> westelike bosveld.<br />
Atalaya Branch Cal<strong>en</strong>dar 2012<br />
bye<strong>en</strong>komste<br />
ev<strong>en</strong>ts<br />
Beautiful photographic cal<strong>en</strong>dar for 2012 printed on high quality<br />
photographic quality paper and nicely bound. It <strong>co</strong>ntains one<br />
photo per month including a short story about the subject matter.<br />
Six photos are in portrait and six in landscape, so some will have<br />
the dates and info along the sides and some along the bottom.<br />
Get it at: Fogarty’s Bookshop or <strong>co</strong>ntact<br />
Lloyd Edwards at raggycharters@gmail.<strong>co</strong>m<br />
A3 size A4 size<br />
69<br />
DENDRON » No/Nr: 43 » November 2011
DENDRON » No/Nr: 43 » November 2011<br />
70<br />
bye<strong>en</strong>komste<br />
ev<strong>en</strong>ts<br />
BERIGTE<br />
Boomplantfunksie saam met Solidariteit Help<strong>en</strong>de Hand<br />
I<strong>za</strong>k <strong>van</strong> der Merwe - Filadelfia<br />
Mnr. Dirk Hermann het in Kameeldrif- Wes naby Pretoria het homself <strong>en</strong> sy grond toegewy aan <strong>die</strong> bedi<strong>en</strong>ing <strong>en</strong><br />
huisvesting <strong>van</strong> arm blanke gesinne. Hier<strong>die</strong> projek, bek<strong>en</strong>d as Filadelfia Ark, huisves reeds ‘n aantal m<strong>en</strong>se wat<br />
ook werk gebied word in onder meer ‘n kombuis wat tuisgebak maak <strong>en</strong> verkoop, <strong>en</strong> ‘n aanleg waar bitum<strong>en</strong><br />
pakkies vervaardig <strong>en</strong> aan munisipaliteite verkoop word om slaggate mee te vul.<br />
Op 23 September het <strong>die</strong> D<strong>en</strong>drologiese Ver<strong>en</strong>iging in samewerking met Solidariteit Help<strong>en</strong>de Hand <strong>en</strong> <strong>die</strong><br />
NG Geme<strong>en</strong>te Lynnwoodweg inheemse bome geplant by <strong>die</strong> sowat 50 nuwe W<strong>en</strong>dyhuise wat op <strong>die</strong> terrein vir<br />
huisvesting opgerig word. Hier<strong>die</strong> bome sal mettertyd koelte verskaf <strong>en</strong> <strong>die</strong> omgewing verfraai. Professor Andre<br />
de Villiers, voorsitter <strong>van</strong> <strong>die</strong> Magaliestak, het tyd<strong>en</strong>s <strong>die</strong> gele<strong>en</strong>theid gepraat oor <strong>die</strong> belangrike rol wat bome<br />
in ons kultuurerf<strong>en</strong>is speel, aangesi<strong>en</strong> <strong>die</strong> gele<strong>en</strong>theid saamgeval het met Erf<strong>en</strong>isdag.<br />
Die geharde boomsoorte wat geplant is was versigtig geselekteer om <strong>die</strong> harde omgewingstoestande <strong>van</strong><br />
winterryp <strong>en</strong> kleigronde te oorleef. Die Ver<strong>en</strong>iging lewer in Desember nog vrugtebome by Filadelfia Ark af.<br />
D<strong>en</strong>drological Society Pays for Radar Scan of Tree Giant<br />
I<strong>za</strong>k <strong>van</strong> der Merwe<br />
The Woodville Big Tree is a giant Out<strong>en</strong>iqua yellowwood (Podocarpus falcatus) standing in the Knysna forests near<br />
George. This tree has a trunk circumfer<strong>en</strong>ce of 8.9m and a height of about 33m. It has be<strong>en</strong> declared a Champion<br />
Tree, and receives thousands of visitors per year. Members of the D<strong>en</strong>drological Society raised a <strong>co</strong>ncern about<br />
the <strong>co</strong>ndition of the tree, since <strong>co</strong>nsiderable crown <strong>die</strong>-back <strong>co</strong>uld be observed. It was th<strong>en</strong> decided to sp<strong>en</strong>d<br />
a part of funds raised specifically for <strong>co</strong>nservation projects on a crown inspection by an arboriculturalist and a<br />
high-tech radar scan of the tree trunk to detect whether there might be tree-rot, in which case special measures<br />
would have to be tak<strong>en</strong> to save the tree. Such surveys are exp<strong>en</strong>sive, and securing governm<strong>en</strong>t funding for tree<br />
<strong>co</strong>nservation activities of this nature is seriously hampered by red tape.<br />
On 28 June 2011 a member of the C<strong>en</strong>tral Committee of the Society joined Mr Daan Loock, an arboriculturist of<br />
Arbor Oxyg<strong>en</strong> based in Australia, in his investigation of the tree. The radar scan with a tomograph fortunately<br />
indicated no major internal decay requiring urg<strong>en</strong>t action. There are signs of outer decay that has to be monitored,<br />
with removal of some dead wood re<strong>co</strong>mm<strong>en</strong>ded. The creation of a larger boardwalk area around the tree was<br />
also re<strong>co</strong>mm<strong>en</strong>ded, to prev<strong>en</strong>t further <strong>co</strong>mpaction of soil around the tree.<br />
On 15 August 2011 tree climber, Leon Visser<br />
from Trees Unlimited in Stell<strong>en</strong>bosch scaled and<br />
measured a Sydney gum tree (Eucalyptus saligna),<br />
which turned out to be a new African tree height<br />
re<strong>co</strong>rd. This tree towers above a stand of gum<br />
trees planted in 1906 in the Woodbush Forest<br />
Estate, Limpopo Province. The tree climb formed<br />
part of a tree measuring expedition organised<br />
by the Departm<strong>en</strong>t of Agriculture, Forestry and<br />
Fisheries, sponsored by Stihl South Africa. Three<br />
giant Mexican Pine trees (Pinus oocarpa) were also<br />
climbed, the tallest of which measured at over 50<br />
metres tall. These sturdy trees with trunks of just<br />
under 5 metres in circumfer<strong>en</strong>ce, were dubbed<br />
“The Three Matrons”. Few pine trees anywhere in<br />
the world reach such dim<strong>en</strong>sions. The pine trees,<br />
like their gum tree <strong>co</strong>unterparts nearby, are already<br />
New Africa Tree Re<strong>co</strong>rd<br />
Adopted from a Press Release by Daff<br />
more than a c<strong>en</strong>tury old. Ac<strong>co</strong>rding to the planting<br />
re<strong>co</strong>rds they were planted a year before the gum<br />
trees.<br />
The Sydney gum tree, measured at over 80 metres,<br />
breaks the previous South African tree height re<strong>co</strong>rd<br />
held by two gum trees, known as the “Twin Giants<br />
of Magoebaskloof”, by just a metre. It stands so<br />
close to the twin trees such that their crowns almost<br />
touch. The trio of world-class champions may now<br />
be called “The Magoebaskloof Triplets”, officially<br />
the tallest trees in Africa, and also the tallest planted<br />
trees in the world. The Departm<strong>en</strong>t protects the tree<br />
stand as a whole as a grove of Champion Trees,<br />
which is managed by Komatiland Forests.