Hydro-ecological relations in the Delta Waters
Hydro-ecological relations in the Delta Waters Hydro-ecological relations in the Delta Waters
A seaond important perspective for ~cosystr?m development is lging outside Che new dams .tn the North Sea, the so &led "Vwrdelta". Eere are on several places good possibUities to aevelop dvne aateas with gradients of fresh dme slacks to salt marshes and breeding place6 fox shore birds. Mnally there are the new terrestrial habitats on the Parmer tidal flats and salt marshes in the closed estuaries. In the estuaries closed first, like Lake Veere, Lake Grevell%en and liaringvliet, large grasslands ate the dominating type of ecosystem. Prm an international poLat of view spontaneous woodlands and patchy environnents with shrubs can also contribute very much to the conservation of endwered species and cmunities. For this reams it is necessary to rnake room for shrub and woodland develepmnt %a the wre ~ecently closed estuaries like the WrIcieearstsftieer aad the Krmer-Volkerak. ~n conclnsion I wonld lika to stress the differences between ttie develsping ecosptems of the famr sslt marhhes and tidal Eliits and the nature reserves on the "old land". Firstly there is a gmat df3ference in size, Mast nature reserves of the pld land ar*, in general, muoh smaller than the Gees in the former eswanies. In the Ntetherlanas there are very Fw nature reserves with a size ef 500 to L50D hectares with undl.stwM sradients in height ad a eatural groundwater regime. This gfm special perspectives in the former wstuaries for those epecies and ecosystems wbzrh depend m large-sale prsc6eses and lwk of disturhitnee. P%$ LbZs readqn splitting up ~f B@ new areas mst be prevented and nature ~wia~w~ent must rrg to cmso~idaze their large-scale character. s.eehdljr we muse mylise that m the ffimr estuatiee W* um deaelop5ng axlsritirig snes. new -sal&, dhila on. the $&d we &re W~\rfn.$ Ilecauw of the non-cymc dynamri&s ern the ecosystem* dn tbe famsr tiaal flaTs and salt m;prslies., eoMervation 62 rhe aettial flora Bnd
favna often is the wrrmg policy, whatever rare the species may be. It is more important to get a good idea af the (abiotic) processes in aad the ecologioal potenzidries of the atea. 0x1 the basLs of this knowledge we must formulate a management plan with a goal for ecosystem development a~ the long run. The long-term goal must be used to evaluate what short-term measurements can be taken. For instmce, with the Long-term goal to st5uslate woodland and shrub develbpment it will be difficult to accept short-term mowiq to canserve breeding habitats for rare shore birds. Mren the lerrg-term goal is the development of grassland ewsysfems a mowing regime during some gears may be quite acceptable, particularly when endangered species are involved. Even in rhe last case, however, it is possible that the breeding habitat gets more and more unattractive. The author is ~uch indebted to J, van Baalen, C. Bisseling, A.R.L. Huiskes, D.J. de JMg and espeeiallx W.@. Beeftink for valuable tornenta on earlier dr&ts of the manuscript. J. Visser (Bi>kewaterstaat, Directorate Flevoland) and G.J. Slab fk'atiofuil Forest Service in the Netherlands) kindly provided some data. BEFERENCES BAKKFIR, T.W.M., RLIJN. J.A. and ZAUELHUFB. F. J. VAN, 1981. Blederlandse kustduinen; landschapsecologie. Pudoc. Wageningcn. 144 p. BEEPTLNK, W.G., 1979. The structure of aalt snarsh cornunitlee in relation to environmental disturbances. Tn: R.L. Jefferies and A.J. bavy (ed.). Ecologisal prowasses in coasCal eavirenmeats, p. 77-93. Blackwell Scientific Publications. O~ford. BEEFTIEIR. W.@. 1987. Vegetation responses to changes 19 tidal inundation of salc marshas. In: 3. van Andel et al. (eds.), Disturbance in gr@Salan&, p, 37-11?. Dr W. Juolt Fublishers, Dordrecht.
- Page 64 and 65: highest trophic potential: nutrient
- Page 66 and 67: period 1980-19$3 in an increase of
- Page 68 and 69: model calculations reveal that a ni
- Page 70 and 71: Table 3 PreUmInary carbon budget of
- Page 72 and 73: Water life of Lake Grevelingen
- Page 74 and 75: macrophytes livkg on or rooting in
- Page 76 and 77: less predictable for water managers
- Page 78 and 79: ILWNEWIJK, A.. KEIP, C., 1988. De v
- Page 80 and 81: XBE CHANGING TmAL LAMXiCAPE I N TEE
- Page 82 and 83: The storm surke of L&Z1 A.D., knorm
- Page 84 and 85: osi* rn@8IOIP m .SL 4 Has F~~ULB 3
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- Page 88 and 89: mudflats have retreated some 100-20
- Page 90 and 91: aq811~33a.e~ pue 3pTatlJS uxaJsafi
- Page 92 and 93: Erosion by waves of sandy shoals (c
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- Page 96 and 97: Implementafion of the Delta Project
- Page 98 and 99: ECOLOGICAL DEVELOWdENT OF SALT MAKS
- Page 100 and 101: fn tidal water systems sedimentatio
- Page 102 and 103: hierarchical position. Tn the egtua
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- Page 106 and 107: wind erasson, desaliuation, aeratio
- Page 108 and 109: Fonner tirtal flats with saltmarsh
- Page 110 and 111: Grevelingen. Lake Veere and Krammer
- Page 112 and 113: As mentioned above aa important que
- Page 116: BEEEXNX, W.D. and 80ZBf&. J. L9M. T
- Page 119 and 120: are determining the dfstrlbution af
- Page 121 and 122: this volume or in Duutsaa, et aL, 1
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- Page 125 and 126: of waterbirds occur regulsrly. The
- Page 127 and 128: . DISTRIBUXIOBI OF WATEJBIRoS OVER
- Page 129 and 130: small bird$ extludiag them vill net
- Page 131 and 132: In order to lsok for relatiouehips
- Page 133 and 134: Table 3 Biomass of macroroobenthos
- Page 135 and 136: freshwater basins. Clearly the pres
- Page 137 and 138: scmthem bottueary o-f the winter di
- Page 139 and 140: OCLURRENCE AND DIET QF B ~T .tUQ 80
- Page 141 and 142: 5.2 H- factors Next to all fartors
- Page 143 and 144: Bewick's Swans (Cygnus columbariusl
- Page 145 and 146: m's activiries do not always have t
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- Page 149 and 150: DOQiWT$QS, G. 4 TWISK, F., 1987. De
- Page 151 and 152: MEININGEB, P.L. and HAPEREX, A.M.M.
- Page 153 and 154: PISCIVORES Litfle Grebe Great Crest
- Page 156 and 157: IPYBRO-EGOLOOIOAL BELATIONB ZN THE
- Page 158 and 159: apart from upstream purification; -
- Page 160 and 161: Storm surge barrier Eastern Scheldt
- Page 162 and 163: - In addition to existing managemen
A seaond important perspective for ~cosystr?m development is lg<strong>in</strong>g<br />
outside Che new dams .tn <strong>the</strong> North Sea, <strong>the</strong> so &led<br />
"Vwrdelta". Eere<br />
are on several places good possibUities to aevelop dvne aateas with<br />
gradients of fresh dme slacks to salt marshes and breed<strong>in</strong>g place6 fox<br />
shore birds.<br />
Mnally <strong>the</strong>re are <strong>the</strong> new terrestrial habitats on <strong>the</strong> Parmer tidal<br />
flats and salt marshes <strong>in</strong> <strong>the</strong> closed estuaries. In <strong>the</strong> estuaries closed<br />
first, like Lake Veere, Lake Grevell%en and liar<strong>in</strong>gvliet, large<br />
grasslands ate <strong>the</strong> dom<strong>in</strong>at<strong>in</strong>g type of ecosystem. Prm an <strong>in</strong>ternational<br />
poLat of view spontaneous woodlands and patchy environnents with shrubs<br />
can also contribute very much to <strong>the</strong> conservation of endwered species<br />
and cmunities. For this reams it is necessary to rnake room for shrub<br />
and woodland develepmnt %a <strong>the</strong> wre ~ecently closed estuaries like <strong>the</strong><br />
WrIcieearstsftieer aad <strong>the</strong> Krmer-Volkerak.<br />
~n conclnsion I wonld lika to stress <strong>the</strong> differences between ttie<br />
develsp<strong>in</strong>g ecosptems of <strong>the</strong> famr sslt marhhes and tidal Eliits and<br />
<strong>the</strong> nature reserves on <strong>the</strong> "old land".<br />
Firstly <strong>the</strong>re is a gmat df3ference <strong>in</strong> size, Mast nature reserves of<br />
<strong>the</strong> pld land ar*, <strong>in</strong> general, muoh smaller than <strong>the</strong> Gees <strong>in</strong> <strong>the</strong> former<br />
eswanies. In <strong>the</strong> Nte<strong>the</strong>rlanas <strong>the</strong>re are very Fw nature reserves with a<br />
size ef 500 to L50D hectares with undl.stwM sradients <strong>in</strong> height ad a<br />
eatural groundwater regime. This gfm special perspectives <strong>in</strong> <strong>the</strong><br />
former wstuaries for those epecies and ecosystems wbzrh depend m<br />
large-sale prsc6eses and lwk of disturhitnee. P%$ LbZs readqn<br />
splitt<strong>in</strong>g up ~f B@ new areas mst be prevented and nature ~wia~w~ent<br />
must rrg to cmso~idaze <strong>the</strong>ir large-scale character.<br />
s.eehdljr we muse mylise that m <strong>the</strong> ffimr estuatiee W* um deaelop5ng<br />
axlsritirig snes.<br />
new -sal&, dhila on. <strong>the</strong> $&d we &re W~\rfn.$<br />
Ilecauw of <strong>the</strong> non-cymc dynamri&s ern <strong>the</strong> ecosystem* dn tbe famsr<br />
tiaal flaTs and salt m;prslies., eoMervation 62 rhe aettial flora Bnd
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