Proceedings of a Meres and Mires Gonference at Attingham Park ...

NATURAL EI{VTRONiIIENT RESEARCH COUNCILTHE NATURE CON -A ERVANCYProceedings of a Meres and Mi-res Con-terenceat Attinghan Park, Shrewsbury,on 6th, 7th and 8th December, 1965Edited byPhi-1i-p Oswald and Antony Herbert

CONTENTSListof those attendingTNTRODUCTTON(Dr. Tom Pritchard ) tSESSION I: HYDROLOGYThe hydrology of peat sites (or" J. v. sutcliffe)Ground-watei conditions and movement (p; H. tand)The measurement of run-o.ff and transpi-ration(D" T" Plinston)Radioactive isotopes in the measurement o-f 'watermovement(p. B. smith)Discussi-on{346812SESSION TI:GEOMORPHOLOGYThe role of salt subsidence in the formation o-t meresand other hollows in the Cheshire-Shropshire Plain:I(9. J. Taylor) l+II(w. B. Evans) . 15Di-scussion Panel: The origin of basins in glaciatedlowlands16SESSTON ]TT:CHEMISTRYDiscussion Panel: Water and peat chemistrySESSION IV: LAND USE HISTORY 28A pedologi-cal approach to mj-re problems (p" Mackney) agThe reclamation and exploitation of mossland inLancashire (e. R. Ha1l ) zgFarming of Lancashire mossland - past and present(a" H. Fitton) :tHistorical investigation o-t lowland basin sites inShropshire (.1" B" Laryson) lZDiscussion 34CLOSING SESSION 37List of references 45A note on the possible use of fluorescent dyes for tracingthe movement of vater (not presented at the conference)"(r. R. smlth) +g142323

AddendumPage 16, after line 3g:Further j.n_formationcan be found in Evans, --"Wilson, Taylor and price ( in prei_;1.CorriqendaPage 7,line 3T:For 1 964 read 196j "Page 1 9, line i 3:For was read i_s.Paoe **Jv 1q tJ, rrrre l-ina zq."iJ.For from r.ead -€orm "Page 21 , li-ne 36:For extnesivePage 26r tine 13:Delete did.Page 28, Line 32:For 1 961 read 1952"read extensive.\

lE3E s. iIP_gr Rru.UIBRgry sLi s t ei_lgq_se {Llenoig-s.Mr. A" Barsby Hydrolcgy Divislon, ldater ResearchAsscciatroir, Medmeirha,n, Bucks.Ivir. J" No B. Bel1Departmertt cf Botany, FfanchesterMr. D" J" Bellamy Deljartmelit o-9 Eotany, DurhamMr. H" J. B. Biz'ks Sloney Sussex College, CambridgeDr. D. J" Boatma.n Departnent of Botany, HuIlMr. G" S, BoultonDepartmettt c-i Ge'ology, Birminghaml4r" E. F{, Chate:: frepartrtreni of Botany, AberystwythDr. G" R. CoopeDepartinent cf Gec*cgy, BirminghamDr" B" Crc1l Chernjstry Divisrort, l'/ater ResearchAssociation, i'iedmenham, Bucks "Mr" R" E. Daniels Depa|t.nent o-f Botany, NottinghamMiss J" Dodd Departnent of Eotany, DurhamMr'. Iil" B" Er.ians Geol-ogical S';rr.,'e)', Le€(isMr. A. H. Fitton Nai-ional Agriculttmal AdvisorySerrrice, Lalrcs .Miss Fi. Fcrsl'th Grcsvenor iulriseu-rir , ChesterMr. A. L. Galiiforci 45, Trerrcr )rivc. Crosby" Liverpccl, 23Mr. D. Goode Department c-i Botairy, Hull-Mr " R" GocdierNatr.ire ConservatrCy, BangcrMr" G. T" Gcodman ltepartmcnt cr.:l Ectany, SilranseaDr, K. M. GocdvayDepartment of EJ-ologyn KeeleMr" A" J. P. Gc"e i{ature Conserrancy, I.iellervoo'Cr Lancs.Dr" B" H" Gre,:nDepartrnent cf Botany, l"lanchesterlulr" II. !i. Grimsharri uhemical- Se:rrice, Itlature Ccnservatrcy,lierrewo.,;d e L?rlC--s .Mr. P" S" Gudgeon Department of Geography, i"IanchesterMr" B" jR. Iial_tDr. F" D. C" Hen;.;'S.:i1 Sur,verr of Ernglaird & tr/a1es, Ormskirk,Lancs "The Haveir, Church Laire, Sompting,Lanci:rg? SussexMr" A" T. Herbert rhe lrlatu.re conservancv, Attingham park

Mr. P" H" Rowlands Department o-0 Geology, BirrninghamProf " F. \^1. Shotton Department of Geolcgy, BirmingharnMiss K, Simpki-ns Department cf GeograPhY, Reacling14r". C" A" Sinker Prestcn Montford Field Centre,ShrewsburyMr" D. B" Smi-thMr" T" R. SmithU" K. Atomic Energy Authority'VJantageNature ConservatrCY, SpeysideDr. J. V. Sutcliffe Hydrolcgical Research Unj-t, Walling-fordDr. J, H" TallisDepartment cf Botany, ManchesterMr. B. J" Taylor Geolcgical Survey, LeedsMr. J. A. Thompson Nature Conservahcy, Atti-ngham Park1l[r" K" Thompson Department cf Botany, DurhamMr. J. B" Thornes Department of GeograPhy, Kingrs College'LcndonMiss W. Ticl

INTRODUCTTONDr" Tom Pri-tchardChairman o-f the Meres and the Mire-c Re*qearch GroupsDur'ng its entire history the Nature Conservancy has maintaineda close relationshj-p wj-th scientists in the universitiesand other institutions where research in ecology and related sub-'iects with a beari-nq on conservation i-s undertaken. Its twinnlrior'1-irroq in. pur-suing this policy have been to ensure thatits own research programmes are not conducted i-n i-so'lation fromthose elsewhere and to obtain specialist advice and lcnowledgefrom outside to assist the Conservancy in lts task of applyinga^nlnain>'l .rienceJv!urrvv tO the LrrL management rrlurtJyLjrtlrrL O-f vr Naticnal NatUre-ReSerVeS.The Mi-d1and Region of the Conservancy has benefited -0ormany years from the scj-entifi-c manpower available in universitiesand other research insti-tutions which has been directed towardsinvestigations on wetland -qites. fn particular, many biologistsare interested j-n the ecclogy of smatl lowtand wetlands which,despite the urbanization, industriallzation and intensive agriculturaluse of much of the region, are a characteristic featureof the North-l/est Midlands, The scientific importance of thisgroup o-0 l-akes and bogs, locally always called meres and mossesrespectively, has become clearly recognized during the lastseven years" 'Ihisi-q mai-nly as a result of the Conservancyrsactivities in organrztng surveys and in encouraging research bythe universities of Keele, Liverpool, Manchester and Nottinghamand by others further afield" The outcome of the'Conservancyts-tunctions in encouraging and making use of these investigationshas been the -€ormatj-on of the Meres Research Group and the MiresResearch GroupThe Meres Research Group was ccnstituted in lvlay, 1962, todiscu the Cheshire and ShrSpshire Meresand especially on Rostherne Mere, a National- Nature Reserve wherethe Nature Conservancy has prcmotecl hydrobiological work byscientists -from the Unirrersities cf L-r-verpool and Manchester,the Freshwater Biological A-sscciationts i,/indermere Laboratory atthe F'f:ffw , v:r HOtico urruan';l o1 catr\91.g.u!_vwf/ tThe lrli-res Research Group had its oriqin in a qroup ofsci-entrsts from various research establishment*c who collaboratedtn 1959 and 196.A cn ccological, peat-stratigraphical and hydrologicalresearch on the North-West Midland Mo-sses, includi-ng Wybunbur,yMoss Nationat Nature Reserve and Chartley Moss, which hassubsequently beccme a Natj-cnal Nature Reserve. In September, 1954,it became a national grcup, whose -first task has been to draw upan inventorv of mir'es in Britain and tc derrolrrn. 'in !Lurrr ufru L\J ugvg!Vy, .tII r-onii;nef LUrrJurruLrvrr ionvith the Nature conservancyrs Biclogical Record.s centre, trredocumentaticn of i-nformation and a centrafized. data retrievalservice, thus -0acilitating exchange cf lcnowledge between scientistsworking on such sitei and the conservatici of an adequater.,anaTo nF tharvr

Whereas both Groups had small and lccalized growing points,their membership as well as the range of topics brought intodiscussicn became .quickly-enlarged and dj-versified. Thisperhaps indi-cates that they have filled a vacuum in the spheresof peatland and -freshwater research" They have prcvided aforum for both experienced and young scientists i-nvestigatingthe sane or si-mil-ar sites to joln in Ciscussion, thus e:changingdata and hypotheses. They are also a .f ccus -0or theConservancy to provide some assi-stance j-n the form of commonservices, such as recording and sampling, especially on Nati-onalNature R€serves " A third -f eature of the Groups is that theyare in a positi-on to review and assess recent progress andtrends, prospects and requirements in a broad spectrum of wetlandresearch and, in this context, are abl-e to provide technicaladvice to nati.onal and i-nternational institutes andag.encies vhose task it is.to formulat.e.research and conservation^^-l -i ^-i ^^};vI--L\-ig>oOne o-f the problems o-f ecoloqical research is to cbtain adequatedata on thb ecosystem as a irncfe, and this is particularlytrue in tire case of studj-es on .Freshwater and peat-produci.ngecosystems" Most biclogists in this field will. be -qeriously"restricte0 unless they are able to know not only the composition'c-f the vater,or peat they are studying, but also the'originand characteristics of the basins containing it, their catchmentareas, the chemistry rf inflcwing streams and other environmental-tactors. There are severe linitations to the extent to whichsuch -factors can be satlsfactority analysed by biologists, butthere are often workers in other fields who are abfe to prcvidemany of the answers or whc could do so if they were engaged inresearch on the s-ites in question.ft is against thi-s sort cf backgrcund that the conferenceof the two GrcuPS was planned, its aim being to

SESSION I: HYDROLOGYChairman: Dr" M" C. Pearson, The University of NottinghamRappo{Leur: I. R" Srnith, T}re Nature ConservancySpeakers: Dr" J. V. Sutclif-Fe, Hydrological Research Uni-tD. H. Land, Geological SurveyD. T. Plinston, Hydrological- Research Uni-tD" B. Smith, United Kingdom Atomic EnergyAuthorityThe hydrologyof peat sitesDr. J. V" Sutcli-f-teHvdr^ol ooical balances are difficult to obtain on peatsites because o-f the uncertainties of catchment boundaries.The special hydrological properties of peat as a catchmentcover are its permeabi-1ity and its moisture-tension rel-ationship"Evidence is limited by the problem of measuri-ng j-n si-tu,lut examples show a very variable but generally low permeability(Boelter 1965) and a high saturated moi-sture content and wateravailability (eaden and Eggelsmann 1964)"Although other studies i_n peat areas may require someknowledge o-f the hyorology, the main val_ue of a hydrologicalstudy o-0 peat catchments is in run-off predi_ction, where thedlfferences in behaviour between peat and mj-neral- soil may beimportant. The main practical problem is the possible e-F-fectof changes i-n land use on the run-o-f-f. If the ef-tect is to bemeasurable the change nrust be. drasti.c; at1 example which hasattracted some attention is drainage" several studies havebeen made of this problem, qhic.h approach .to a- greater orlesser extent the'classlcal method o-f experiment using pairedcatchments, where a change is nade on one of two similarcatchments a-€ter a period of calibrati_on"At Moor Houser oh the Pennines, run-of-F has been measuredfrom -tour catchments with drained, erooed and natural peat cover(conway and Mi]lar 1950)" The catchments provide interestingcomparisons in flow, the peaks being somewhat earlier andhigher on the drained and eroded catchments than on thenatural catchments; on the other hand flow ceased on severaloccasions from the former but not from the latter. However itis difficult to dr.aw firm conclusions from simple comparisonof peak flows, because size o-f catchment is con-tounded withtreatment aS fho l:v'rror^ ,-'tChmentS are undrained." FOr instanCe,

un-o-ff is delayed on the larger undrained catchments, but recentempirical relationships between 1ag, area and slope show 1ag tobe proportional- to area to the power of _three-tenths and inverselyproior.tonat to the same power o-F slope (nash 1960). Thus onewould expect the 1ag -trom a doubled area to increase by about aquarter. This example is quoted to urge caution in attributj-ngthe whole o-f the difference.i=n-.behaviour to land use differencesand to suggest further analysisAnother interesting study iras recently been published o-0 thehydrological budget of a raised bog area of North-!.rle5tern Germany(eaden and Eggelsmann 1964) " In a comparatively lour and dry areaat Koenigsmoor a comparison has been made between a heather-coveredraised bog area and an adjacent area o-f tGerman raised bog culturer ,drained since 1912 by tile drains and si.nce used as grassland"It was found that the run-off from the uncultivated area was muchnore variable than the run-off from the grassland; for j-nstancepeak flows in the -former were -frequently two to four times greaterthan in the latter. This is attributed to the predominance ofsur-Face run-o-ff in the uncultivated area, which is saturated. -Foralmost all the year, while run-off -from the grassland is delayedbecause of the storage above the vater table in the drained area.This is illustrated by the average depths of water 1evel overeight years, which are 13 cm below soil 1evel in the uncultivatedarea and 7O cm below soil leve1 in the grassland"When comparing the results o-t these two investigations, thedi--f-ference between the surface drainage at Moor House and the tj-1edrainage at Koenigsmoor should be remembered, as well as the contrastbetwen the high rain.Fal1 at the former site and the 1owrainfall at the latter.other investigations relating to the hydrology of peat drainageare being carried out by the Hill- Farming Research Organisationand the Macaulay Tnstj-tute on a rarsed peat bog j-n Lanarkshire,where a 17-acre site was Crained after calibration (Hi-ff FarmingResearch Organisation 1954), and by the Agri-cultural- Institub onblanket Peat j-n lreland, where drained and undrai-ned one-acre plotsare being observed (Anoir 1965)"Ground-water condi-tionsand movementD. H. LandGround (or phreatic) water is that in the zone of saturationand is di-stinguished from vadose (including soi-1) water inthe overlying, superficial zone of aerati-on. rn the zone ofsaturation all Pore sPaces i-n the rock (a terrn .yhich includes sof tmaterials such as sand, clay or peat) are filled with vater underhydrostatic pressure. The upper surface of this zone is the4

water table, which is shoivn by the leve] of standing water ina well or bore.the water table lntersects the sur.face,ground water is dischau'ged "^/here by springs, seePages and evaporation"The altitude of the water table is variable, partj-cula:rlyscme distance away from discharge areas"Grc-runcl ivater ]noves accorciing to Darcy,sLaw, which is:-Veloclty = permeability x h1rd13rl1i" gradient.Permeability (or hydraulic conductivity) is thc capacity totransmit rvater and is measured br.. the coe-fficient o-Fpernreability (gall-ons per day per -cquare foot), urhich is the--flov (g"p.d" ) through unit area (f sq -ft) under unit hydrauli-cgradient (slope of the vater tab.r-e of 1 ft/tt). Permeabilityis generally greater horizontally than vertically. The yieldof ground wa cer -trom a given volume of rock i_s measured by thecoefficj-ent of storage (a ratio expressed as a decinal), rvhichis the voLumc of water (cu ft) released -frorn storage from acolum:i o-f the aquifer of unit area (f sq ft) per unit loweringo-f the water table (i ft).Permeability and storage may be measured in the laboratory,but representatj-ve samples are not easy to obtain. Simplefield rnethods have been described by peeve and Kirkham (rglr);pumping tests, vhich are more accurate but rnuch more expensive,are described in v.rricus texts (e.g" Todd f959)"Ground water forms part of the hydlologieal cycle, and forany given area the ground-vater part o-f the vater budget may beexpressed as:-Infiow= outf1oly t change in srorage,Inflow cons:-sts of direct infiltration -from precipitation,influent seepage -trom rivers and lakes, underflow within theaquifer from adjoining areas, and artificial recharge" outflowconsists of evaporation (i-ncluding transpir.ation from plantswith roots reaching ground vater), springs and seepages(includi-ng discharges into streams, lakes or the sea), underflowwithi-n the aquifer to adjoining areas, and abstractionfrom wells " These items may be estirr.ated from measurement o.fthe gosition of the water table and o-€ the coef.gicients of-storage and permeabilityr dS well as from the usual surfacehydrometry.Very ]itt}e work has been Cone on ground rvater inrelat:-veiy restricted basins such. as contain the majority ofmeres and mj-res o-€ this country, rRecent studies by Meyboom(1963) i-ndicate that each small basin has its ovrn rechargedischargesystem, but further ryork on this scale is necessary.Loca1 conditions are important, and each mere or mj_re basinmust be studied individually. i

The nie.;surement of run-offand transpirationD. T. Pl-instonStrean -flovr is usually obtained by measuri-ng the stage(water le.rel ) and converti.ng thj-s to discharge, u--qing the stagedi-schargecalibratron for the stream secti-on. The stage measurementis rel-atively easy, and it is the determination and thereliabj-li-ty of the stage-discharge curve whicLr present problems"Each -qtreari has a stage-discharge r'elationshi-p governedprrmarily by the shape of the cross-iecti-on, the b?:d-s1ope andthe rcughnesq o-S the bed and banks" In some cases it j-s possibleto -ti-nd 3. rtaturll strea:n section where thi-s staqe-di-scharseretationsliip rs stabfe, that is not chan.oing wi:ih time. Such acontrol section could, for exampl€, be a rock bar in the streambcd" i{ovever natural qtream sections are usually subject torapid scour at l.,igh -tlovs folloved by gradual- accretion orsJro".ling as the 01ov subsides. Ef.fectively thj-s gives a differentstage-discharge carvc for ri-sing and falling stage" Dovnstreamconditiores are also impoz'tant, and any change in the streamcon-frguration or obstructions doumstrean will affect thebehaviour at the chosen section"Either the veloci-ty-area method or the salt dilutionnethod (eritisir StandarC 36Bo 7951) can be used to determinethe staqe-discharge curve for a natural- section. Both methodsin'oIve-the measr,.iement o-f indivi-dual stages and dischargeso\ier -he range of flow experienced" The velocity-area rnethodshould give inCi-vidual Cischarges to an accuracy o-t 5% - IO%,depending on the experience o-f the operator and such -factors asthe :rate of change o-f the discharge during the measuring peri-odand the rrorlndl ity of the velocity distri-bution at the gaugingsite" The dilu-tion method shourld give individual results ofgreatc:: ,3ccurac) (z* - 4%), since the measuring period is quiteshort ano it is not necessarv to measure the stream cross-section"For more accurate stream-gauging, especially when a longpeliod of gauging is .Foreseen, a control structure (one o-t thema.'ry types of wei:^ cr a fl-ume) is undoubtedly the best solution,Thc stage-discharge curve is fixed provi-ded the str"ucturie iskept clean and free from damage" Furthermore, the calibratj-oncan be dererrni.ned theorcticall-y or by model tests to a highdegree o.f accurac].. (better than 1%). Details of the variousstructures can be found in the'literature (eritish Standard 36BO1954; Ackers and Haruison 1963; Crump 1952; Siirger L964) "In choosing a sultable structure for a strealn, the -0o11owing-factors rnust be consi-dered:-(a the range of discharge to be measured,/r, the acceptable upstream water leve1 limits,the po-e-sibility of silting and(d the possibility of high tail-water levels.

The range of discharge must be estimated, bearing in mind theprobable life of the structure or the duration o-t theexperiment, This range often govern-q the choice of structure.For example, a V-notch weir can be used for a 154-fold rangeof flow lrithin the limits 0.0C8 - 4"38 cusecs, whereas acriti-cal depth flume will measure a many-thousand-foId range,being limi-ted only by the width o-f the stream" The acceptablewater leve1 limits are usually fixed by the depth of thestream channel and, for the best accuracy, the widest possiblerange of stage should be used. Silting upstream of the structureis a probiem when using a thin plate veir or a broadcrestedveir" Tri-angular profi-Ie weirs (crump weirs) andflumes are l-ess sensitive to silting, as they pass siltadequately"Drowning of the structure due to high downstream waterlevels can be avoided by raisi-ng .t.he altitude of the structure.This is less necessary with a Crump weir or flumer &s thesecontinue to operate normally with fai-rly high tail-waterlevels "The accuracy of gauging vhen using a structure is usuallygoverned by the accuracy of stage measurement. At 1ow stagesany systematic error due to poor zeroing will have a ProPortionatelyhigher ef-€ect than at high stages" It i-s thusimperatj-ve that regular attention be given to the vater leve1recording systemTranspiration can be measured with a lysimeter, a waterbalance being dravrn up for the control plot" To avoid havingto make assumptions about the water storage, it is pre-ferableto uqe a weighi-ng fJrsimeter, by which such changes may bemeasured. Non-weighing lysineters are thus restricted tomeasuring potential transpiration when the lysimeter isadequately irrigated or to measuring actual transpirati-onbetureen perlods when the vater storage can reasonably beassumed to be the same.Various weighing techniques have been used, includlnglever balance syitems (r"icllroy and Sumner 1961)' hydraulicpressure systems (Forsgate, H-osegood and McCulloch 1964),lloating systems (ring, tanner and Suomi 1956) and load cells.The problem is that of measuring, with sufficient sccuracyta smal] change in weight o.f a large soil-water block.The lysi-rneter isolates the soil block from its subsur-taceenvi-ronment" Consequently there will be discontinuities o.fthe vater regime and of the thermal regi-me at the base andsides o-t the tank. There may also be di-scontinuity of thesurface cover. These boundary e-ffects must be minirnized asmuch as possible if the results are to be representative of-0ieId conditions. The natural soil- moisture tension gradlentmay be restored to some extent by applylng a tension at thebase o-t the lvsi-meter with porous sucti-on candles" The thermal

egirne dj-seontinuity eaii be mi-nimi-zed by having as small an air gapas Doqqible rOUnd the tfnk,and aISo bv usinc as laroe:lrrcimatar4J.Yv4jJlrrlvLvIas i-s practi-cable"The larger the lysimeter, the more representative of fieldconditions will the results be" On the other hand wei-ghingdifficulties increase with size" It is desi-rable there-tore to seta minimum acceptable veighing accuracy and to have as large alysimeter as the combinetion of veighing methoC, accuracy andfinancial considerations allows"Radioactivej-sotopes i-n the measurement o.f water movementD. B. SmithRadioactive isotopes provide an additional technique tosupplement the conventj-onal methods o-t the measurement of watermovement" To make the most e-0fective use of thi-s new techni-gue,the aovantages and disadvantages o-f radj-oactive tracers have to beappreciated.One speci-al advantage of isotope tracers is that the tracermaterial can be chemicatly identical to the element being tracedand there-0ore can provide a reliable tracer even when chemicalreactions or physical changes take place" A second advantage isthe ease with whi-ch the tracer can be located and measured, veryo-Ften in situ in field investi-gations.A brief summary of isotopes and isotope technigues particularlyapplicable to vater-tracing in peat follows.(f) Characterj-stics of radioisotopesRadioisotopes are isotopes of an element vhere the addi-tion orsubtracti-on of one or more neutrons from the nucleus has producedan unstable -form o-f the nucleus" The isotope is nearly identicali-n chemical and physical properties to the normal element" Theunstable nucleus can change by emitting alpha particles (heliunnuclei) cr beta particles (fast electrons) often together withganma rays (similar to high energy X-rays)" The change of thenucleus by these emissionc constitutes radioactive decay. Therato oF c,h,arroe of the activity 1s expressed as the 'half-li-Fe' (orIgLVthe tine taken -For a gi-ven amount of the radioisotope to reduce toone hal-f ) .The 'quantityt of radioactil'ity is expressed in terms of thenumber o-t disintegrations per u4r!t time, and the unit is the curie,which is equivalent to 3"7 x JOru disintegrations per second"

(Historically this was the disintegration rate from 1 graradj-um. ) t'tore usefut- uni-ts ire the mi-tficurie (g"Z x 107and the microcurie (Z,l x rd d.p"s. ).(2) Detection of radioisotopejThe alpha partj-cles are very short-range and are of litttepractical use -flor field application"o-fd" P" s.The beta particles are more penetrating; high energy onescan penetrate up to 1 cm of water. They can be detected byseveral methcds, which include Geiger counters and photographicplates" The efficiency o.f detection is high from snall- samples,but lov from larger samples or from j-n situ measurements wherea detector is submersed in ryater (since the water absorbs theradiation) "Gamma radiaticn is nuch imore penetrati-ng and hence can bemeasured at very 1ow concentrations in large volume sanples,usually using a scintillation counter. fn particular, acounter immersed in a fairty large volume of water (or in ahole in waterlogged ground) can detect very tow levets oftracer" For in situ measurementq, a radioactj-ve traceremittino oamma radiation is desirable"J *"""'(:) Health considerationsPrecautions must be taken when handl-ing large amounts o-fradioactivity, but these do not provide any difficulty inmost ground-water tracing investi-gations, where a .tew tens o.€nil-licuries of gamma-emitting isotope or a few hundredmj-11icuri-es o-t beta-emitting isotope may be used"When radioacti-ve material is to be used in potentialdri-nking water, mcre stringent precautions are necessary"The concentraticns o-F various tracers which are safe even-tor continucus drinking are given by the InternationalCommi-ssion on Radiological Protection. These concentrati-onsare very variable, depending on the i-sotope, but i-n generala1lov the use of much more activity than that required forreasonabli accurate measurement by refined detecti-ontecnn1ques "ft is of interest to note that o-0ten the concentrationof a radioisotoPe which can be measured convenientl_y i-s much-turther below the I.C"li.P, recommended 1evel than that foran alternatj-ve chemj-cal tracer. As an example, river f lowmeasurements using dichromate as a chemical tracer havebeen carried out i-n vari_ous countries with betweenO"l ng/Iitre and 1"5 mg/titre" ?he World Heal_th Organisationrsrecommendeci drinkincr water limit j-s O.05 mg/titre.Corresponding figures for, say, sodium 24 show tnit tracing

could easily be caruied out with 0.15 ytc/cu ft, and even the moststringent I"C"R"P" requi-rements recommbnd that 0.6 1tc/cu -ft is thelimit -tor continuous drinking. An additional safety factor isprovided by the half-tife of the isotope, since the sodium 24decays by a factor of trvo every L5 hours" A chemical contaminantis only removed very slovly by adsorption.- . , , ,...Before undertaking radioactive tracer investigations involvingsur-0ace or ground vater it is necessary to obtain permission-trom the Ministry of Housing and Loca1 Government.(+) Selection o-t tracer(a) Surface watersSuch applications as river floru measurement can utilize afairly wide choice o-F radj-oisotope, governed by the type of radiationrequj-red (usual1y high energy gamma radiation), the half-1ifeo.f the isotope, health con-siderations and loss from the rvater byprecipitation or adsorption" Isotopes that have been used incLudesodium 24 (half-life 15 hours), bromine 82 (narf-li.fe 36 hours),iodj-ne 131 (frarf-ri-ee 8 days) and chromium 51 (haI-t-life 27 days).(b) Ground waterThe choice o-F tracer is pri-ncipa11y governed by the problemo-t loss by adsorption" This also restricts the use of chemicaltracers and dyes. However, by careful choice of tracer, radioisotopescan provj-de much better tracer materials than any of theconventional chemical or dlrs materials" Isotopes used includebromine 82 (as bromide), iodine 131 (as iodide), chromi-um 51 (asEDTA complex) and cobalt 60 (as cobalticyanide, half-life 5"3years ).The above isotopes all emit ganma rays and can be detected insitu, However, this type of tracer can be adsorbed in certainstrata (particularly those with a hi.gh clay content)" To avoidthis problem, it is necessary to use tritium as the tracer" Thisis an isotope o-t hydrogen, vith a half-1i-fe of 12"3 years" Itemits only very 1ow energy beta particles, which makes itdifficult to detect" Tn situ measurements are not very practicableand samples have to be taken for laboratory assay, using a1iquidscintj-11ationcounter,oI,vhenhighersensiti-vityisrequired, the sampJ-e is converted to hydrogen gas for gas counting"Tritium has the advantage over all other tr3cers that itfaith-fully follows the water-movement (Possibly with a slighterror arising from an isotope eff ect ), V/hen it j-s used as a groundwatertracer, a negative result indicates that the water is notmoving to the sampling point, whereas with alt other tracersthere-i-s the possibility that the water is noving to the samplepoint and the tracer has been lost by adsorPtion" This advantage4r\

makes tritium a very use-€ul tracer, particularry for longterminvestigati-ons, in spite o-f the disadvantage of havingto take samples for measurement(!) Applications o-F r.adioisotqpe tracers(a) River fl-ow measurementChemical tracers have wide application to river -tlowmeasurement" Radioisotopes have some advantages, particular1yi-n polluted or saline waters (clayton and smith 19c3).(O) Ialater movement in peatt{ater movement in Sp[eg4u4 peat is extremely s1ow. Some1aboratoryworkhasbeffiiedoutinRussia,.usingsu1phur35 (ha1f-life 87 days, 1ow energy beta enitter) in the form ofsulphate as tracer (Volarovlch, Churaev and Minkov 1957 ).Other worlc includes an investigation on the North Yorkshirelvioors, usi-ng iodine 131 and tritium as tracers " Themovement was so slow that the B-day iodine was o-0 little use.The tracers (eOO mc of triti-um, 10 mc of j-odine 131)were injected 50 cm deep into a gphag4um drainage bog on ahill side wj-th a stope bf 1 in IZ:--TTe-peat aepth was about1OO cm, and spring water kept the surface of the bog wet.The bog was sampled with a three-dimensional network producing+5O samples" Samples were analysed with a liquidscintillation ccunter and showed extensive diffusi-on of thetracer over the -tull- depth of the bog" The average movementwas 18 feet in 18 months" This work will be published later"F-urther trork is in hand on a raised bog, and initialresul-ts a-fter one year indicate a slower movement than that-Found in the previous investigation" Investigations arerequired on typi-cal blanket peat and may also be of interestin Phragmites deposits"(6) Applications of natural tritiunThe carbon 14 method of dating carboniferous nateri-al isnow well establj-shed. A similar application exists usingtritium. A very smal1 amount o-t tritium j-s formed in theatmosphere by the action cf cosmic radiation" Thls isbrought to the earth as rain, and sonne enters the groundwatercycle" In pri-ncip1e, by measuring the tritium contentof a ground-rvater sample, some informati-on can be obtainedabout the time which has elapsed siitce it fell as rain"This picture is over-si-mplified, since thermonuclearexplosions inject much more tritj-um into the upper atmospherethan that produced naturally" This tritiun thenoccurs in rain, and the concentration varies annually as the44II

obviously has not occurredr [o confident answer could be givento the second al-ternative.-Lastly the management problem of maintaining a naturaipeatland where the surrounding area has been extensivelydrained was discussed" The solutions o-ffered to this di-tfiarr'r*-n-^1"'1 ^*LU! L yI UUrEllt , c-F maintainino both a hioh.vaterJvv Lr! q rrryir V'/O, L\:iI table LCTLTIE: and CiI thenatural- flow rate $/ere recircul-ation of the effluent and/orconstruction of an impermeable barrier. The barrier woul-dbe created by bui-lding a c:ncrete or puddled clay wa11, byusing sheet piling or by injecti-ng grout or betonite mud.The discussion indicated that hydrologists have manyideas and methods to o-ffer but littt-e direct experience ofthe probbms arising in m.er.e and mire ecology"t-)

SESSION II: GEOMORPHOLOGYChairman: Professor F" W" Shottonr FoR.S.'Th lrru e IIn vrrrvv!J!uj i vers i tv n F Ri rm-i ir ah amRapporteur: P. ldorsley, The University o-F ReadingSpeakers: B. J. Taylor, Geological- Survey!il. B" Evans, Geological SurveYDiscussionPanel:W" B" Evans, Geological SurveyDr. F" Moseley, The Unlversj-ty of BirrninghamE" G. Poole, Geological SurveyB" J. Taylor, Geologi-cal- SurveyT. H" l'/hitehead, formerly Geological SurveyThe role o-f salt subsidence in the -tormati-onof meres avrd other hol]ows j-n the Cheshj-re-shropshire Plain: IB" J" Taylor!/ork by the Geological Survey during the past decade has ledto a better understandi-ng of the mechanism by vhich subsidence ofthe ground may occur af ter solution 6f sndoll rri rnrr r^nr'11 salt i-nreCi OnS oF 26nnoci:hl o r.:i 4f3f f .There is still some degree of uncertainty in our understandingof the processes involved, because cause and e-Ffect can hardlyever be linked, except by i-nference, and, in additlon, the greaterpart o-f the Cheshire-Shropshire Plain is covered by thj-ck glacialdeposits whj-ch mask the solid rocks below" Nevertheless, ourcument hypothesis appears to worl< and tn cariqFrr rho 14rr911l'1'1phenomena.There are two main salt-bearing groups of strata in theKeuper, the l-ower about 600 f t thick and the upper about 1 ,3OO f tthick. These two groups are separated by about I'OOO ft of mudstonethe Middle Keuper Marl-. Since the Keuper as a whole is foldedinto an elongated syncline, the two sal-iferous formations comern ^n^n 'i rr +"'cLV Lr Vl/ rrr Lw\ wj-de curved bands o-f country, broken in places byfaults, in thc central region of the syncline.1A t-t

There is no true outcrop c-f the salt measures, since theyare completety dissolved i-n the zone of ground-water circulation.Instead they terminate against the base of the zone o-f circulation,which is generally between 2OO and 400 ft belov the baseof the glacial drift, and they are overlain, in the 'outcroptarea, by brecciated and disturbed marl let down over the dissolvingsal-t" r,/here, because of the stratal dip, the salt is deeperthan the base o-f ground-water ci-rcuJ-ati-on, there is no solution,but in the routcroprzone, which in places may be several mileswide, there is a slow degradation cf the salt, which proceeds,normaIly, dt about the same rate as the general lowering of theland-sur-tace" It can be speeded rip if the.brine that -forms onthe top of the salt is pumped out. Fresh vater enters the groundto replace the brj-ne ano solution occurs where it makes contactwith the salt. Brine-runs develop in roughly radial -tashiontowards centres of heavy purnpi-ng, and their course may be modj--fied by the fact that their tend to develop along the strike ofindividual salt beds"Collapse o-f the ground fo1lovrs along the brine-runs, tend--]ng to be most marked at the end di-stant from the poi-nt o-flabstracti-on" \,fhere brine has never been pumped there may be naturatbline-runs, whj-ch have caused slow suUsid.ence -from anci-enttimesrrthe bri-ne -finding its way out o-€ the area by slow percolationthrough pervious deposits possibly in buried channel-s. Someo-f the modern subsidences may be due to the rejuvenation o-f th'eseancient systems; others are new. A system of brine-runs startedby artificial abstracti-cn may ccntinue active -tor many yearsa.fter pumping has ceased.The roleof sal-t subsidence in the formationo-0 meres and other hollovs in the Cheshire--qhropshire Plain: IIl/" B" EvanS\dithin wet rcck-head areas post-glacial subsidence isstrictly localized" \nihere thick sands lie at the.surface'sporadic crater subsidences occur. These are funnel-shapeddepressions, almost circular in ptan and about 2OO yards in diameter"Thei-r -0ormation appears to require flcwage of waterloggedsand into underlyinE cavities along the rock-head"l,lore widely distributcd are l-inear subsidences, found onjclay land, parti-cularly w{ere there is an underlying layer -ofvaterlogged sand., and resul-ting- from solution o-f rock-saf t bystreams of brine running on rock-head" They are best developedin the l"liddlewich-Sandbach area where wi-1d-brine is pumped

intensively -from the Upper Keuper Sal-iferous Beds, here lying some25O ft fronr the surface over a vi-de area. The channel-s are exaggerated.analogues c.f coal mi-ning subsidence-s.'ti'Ihere a brj-ne channelis sufficiently rvi-de, usually above about 75 yards, supercriticalsubsidence produces a -flat-bottomed trough, ccmmonly flooded whereit has sunk below the urater table" Iilarrcwer channels producecritical subsj-dences, equally deep but wj-thout a flat-bottomedform" Sti11 narrower ones i-nvolve sub-criti-ca1 conditions, whichproduce shallow hol-lows difficult to reccgni-ze certainly as subsidences.A11 three types are gently curved i-n plan and cross therivers and streams without diverting them. Some notch the interfluves,though the surface abcve an individual bri-ne run, o-0tenseveral mi-les longr ffidy be broken up into several hollows separatedby lengths along which subsidence has not yet occumed" The acti-veholl-ows are marked by subsidence steps, simulating faults, andusually up to about 4 ft high. Ncrmal rfaults'result -trom the extensionof the surface closq to the limit line of subsidence: reverse'faul-ts'are found closer to the centre line of the hollow" !/herethe structure of the underlying strata is knovn j-n detail, mosthcllows foll-ow stri-ke, and they may mark the up-di-p limits ofindi-vidual beds of rock-salt,Away from the area o-f brine-pumping there are analogous ho11ows,though these rarely show any signs oi acti-ve subsidence" Particular1ynotabl-e are the basal subsidences, which -9orm along the up-diplimit of each of the two saliferous formatj-ons. Many of the largermeres around Knutsford are o-€ this type and lie at the base of theLover Keuper Saliferous Beds; several smaller mires such as Bagmere,Brockhouse Moss and \'./ybunbury Moss appear to mark the base of theUpper Keuper Saliferous Beds. In addition several linear subsidencesare associated with major faults where these limit shallow rock-salt"Almost all the known subsidences are believed to have criginatednaturally, althcugh many of the mcst conspicuous have been accentuatedby purnping" Several- contain appreci-ab1e thicknesses of peat, inplaces warped by subsidence, and the hollows are -frequently fol-l-owedby long-established hedge lines and in places by pari-sh boundaries.The brine presumably once outflcwed through brine springs, vhosePresence was the prlme cause cf the establishment of the salt townso-t Cheshire"Discussion PanelThe ori-gj-n o-t basins in glaciated lowlandsThe -fj-rst guesti-on that the panel dealt with was vhether thereare any criteria, especially super.r.cicial ones, for deterrnining theprobable mode of origin of enclosed depressions (or basins ) indri--ft-covered lowlandsr dS gaps between glacial drift ridges, kettleIO

holes- qi:hq.idence hollows over saliferous'Triassic beds or ar4vJtcombj-nation of these, and whether there are any other possibleorigins for such depressions:Mr. Poole said that probably the best examPle of an oldlake of the Cheshire-Shropshire Plain is the !/hixa11-Fenns Mossarea. Thls obvi-ousIy originated as a lalce when the iceretreated and lrhen the general 1evel of the water fel1 as aresult of the draining of Lake Lapworth; it lies between twomorainic ridges and is underlain by inter-morainic outwash"Two old Lake Lapworth levels at 33C and 3O5 feet can be recognizedall the way round the basin and these have not beena-ffected by salt solution" However, the existence o-f somesaliferous beds was adnitted. The origin of kettle holes andsubsidence hollows is problematic; they could by polygenetic"Subsidence holl-orrrs have analogies with simil-ar types in theNorririch area of East Anglia, where chalk collapses after solution(Bennett 1884) and resutts in simi-lar hollcws in boulder clay,even under 2OO -feet of driftMr. Whitehead said that every case has to be considered oni-ts merits and that no general criteria can be applied. ft isdifficult to say whether the meres around Ellesmere u/ere causedby salt soluti-on. Although i-t can be shcwn that some basinsare due to sal-t sol-ution, this obviousl-y does not apply to all,for some are not underlain by salt-bearing roclcs. Glacialdeposi-ts gave rise to encl-osed basins in a number o-f dif-ferentways" The dirt in the ice was unevenly deposited and couldtherefore produce enclosed hollows without any outlet. rce ordri-ft deposits could bl-ock a va11ey, producing a hoIlow; goodexamples are to be seen in the north o-€ England, but nct in thecheshi-re-shropshi.re Plain" Hot lours could al-so be -formed by thedi-tferential occumence cf perennially frozen ground, but Mr"Whitehead could not thlnk of any basi-ns in Shropshire where thismlght have occurred" Kettle holes were caused by the rneltingo-f bloclcs of ice, either wholly or partly covered by drift, andoccurred in areas vrhere the ice mcvernent had become very stuggishor had ceased al-together; j-n other ryords they were essentiallystagnant ice phenomena" There are areas in Shropshi-re wherethese condi-tions did ;';-: occur and it is therefore reasonable toexpect sorne o-t the basins to be true kettl-e hotes, for instanceBomere and Shomere; other pools near by may al-so be related tothe same broad area of stagnant ice.Pro-fessor Shotton mentioned thermolcarst pits caused by thedifferential melting of the permafrost; he hid seen them inAlaslca and wae Aiz'l\/.r^r4pident -i"';;;;i., that he had Seen nothing similarin thiswhere trees have been cut doum,"o""iiy]"theground microcl-imate can be cornpletely altered and the permafrostcan melt in a most unpredi-ctabl_e way" A hol_e appears, up to aboutten feet deep, vhere a cylindrical brock has. droiied doynl trre17

hole fitls with water and it is possible to see its vertical wa1ls.This can happen naturally, but is more -frequent where human i-nterferencehas-taken ptace; it occurs predomiirantly in sj-lt terrain,but always where tilere is permafrost only a few feet down. Thesethermokaist pits are quite di-Fferent frcm either pingos or themeres j-n that they are much smaller and almost vertical-si-ded.]vtr" Errans sai-d that he would not claini that he could recognizea q ninoo q-i te rri th r-orta-i ntw trut thaf there vere a number o-f sitesyrrfyv Jr LU w! Lrr vur LqrrrLJ,which-had speci-al features which one miglr.t think about as Possiblen.incrnq- nar,t.ir-rllar^lrr a orouo oF hollo\rr-S hoj-uroon AlsacrefyallvvJtand Cfe\Me.t/qrLru4rqr +Jv4t/ vrJ+tfre-rims of these peaty depr"essions are raised, probably five toten -feet above the surrounCinE level of the plain" There is a veryoentle rise and then a sudden steep fall into a central depressiontrirrori rrr-ii-h neat"t !4ruu w I LrrThere are not yet enough data about the materialr\surrounding the holes" In on e case, the peat overlies Upper Boulder'a-r-"- 1-"+ +L^v La-y t U[ L Lrrc surrounding lariu is sand and gravel" Near the M"6there is a similar hollov, and here the surrounding land is bouldernl:rr >nd tlna ryl3fgrial in the hOllOrr iS Sand; Sand alSO UnderlieSthe surrounding boulder clay" There is thus some evidence to^..--^^L+l^^!>uugc->L Lrrd.u the sur-face material around the hol-low does not occurbelow the hol]ow" A possible sequence could be:-)(") ground ice gradually forming a dome by accretion of pore-water;(b) erosion over this dome removing material from the top;(c) collapse as the ice melted, forrning a crater with a raisedmargin"This mechanism could have ryorked over a 'cairly protracted period of+i -^L l-llrE: oDr" Moseley said that it vas necessary to distinguj-sh betweensalt subsidence hollows and hollows caused by glaciation; i-f' theorigin of a hollow in glacial drift rvas tc be determined, it had tobe considered in its environment. There are many part o-f theCheshire Plain where one can arrive at a satisfactory conclusion bydoing this" It is no gcod co]lsidering a hollorv on i-ts ou'n andexpecting an anss/er; it is necessary to consider the nature o-F thedeposits over a fairly wide arear dS many o-f these hollows areassociated wi-th mounds and are -found in quite rvel1 de-Fined patches"The:area south-east of \a/ybunbury, for exarnple, shows a boulder clayplateau surrounded by a contplex of hollols aud sand-cl.r.,r -*J moundqmostof the mounds beiirE sand-dominant" In this sort of situationone is probably deal-ing with deposits cf a stagnating ice sheet.At one site in this area pcat only 1O,OOO years cld beneath severdl-0eet of sand indicates the extent of post-glacial wash possible insome environments, and this makes the cverall _freshness oftopography of the mounds and hollovrs all the more remarlcable" Bycontrast Wybunbury Mo-cs is a deep holl-ov and the sands near by areflat rather than in mounds; such a holl-ow coutd well be theresult of salt subsidence" This mounded topography re-flects theirreg,ular lenti-cular nature o-f each sedirnentarf riyer; Dr" Moseleythought that consequently the tMlddle Satrd! - f Upp-er Boulder CIayrterminologysuggestive of continuous horizons strburA be abandoneb.18

Mr"Taylor said that peat-fi1l-ed hollows abound in an areathat includes Delamere Forest, Little Budlrorth and Sandivay. Herethere is a great spread of glacial sanc and gravel of hummockyform and possibly cf morainic origin. Some of the hcllows couldbe the resurt or have been accentuated by sal-t subsidence, forsalt at shalloui depth has been proveo in- a Geological Survey borehole near Court House, Delamere, and in a bore for the CheshireBrine Subsidence Compensation Board on the east shore of Oakmere.But other parts o-t the same area, with simil-ar hollows, aremani-Festly not underlairr by sa1t, as was proved by the deep boreat Austin's Springs, south o-0 Abbottrs Moss. Thus the onty vayto be sure that a particular ho11ow i-s or is not due to saltsolution was by the use of bore holesDr G.R.Coope said he rvished to make three points. First, indi-scussing the mechanisms of hollow formation due to salt subsidence,he believed that it j-s unwise to restrict attention to driftcoveredareas There are well-knoum areas where salt subsi-denceis going on wi-thout a coverj-ng o-f drif t; it would perhaps bebetter to look at these areas before tryi-ng to explain what isgoing on beneath the drift" He saj-d that in Worcestershire he hadseen interesting ef-fects o-0 salt subsidence, including large water--fj-lled hollows and associated long fj-ssures wj-th trough -faultingunobscured by any drift on top. Dr"Coopers second point was tosuggest that the raj-sed ri-ms, around hoI]ows sui;pected o-t bei-ngpingos may have been produced during cold phases by water -freezingin the hollows and the expanding ice pushing up ridges around them"Dr.Coope's -fina1 point vas that interpretation of the eeology ofZone III beetles suggests that the climate in Britain at thatperiod was of a -fairly col-d subarcti.c type; the insects found.inZone IT peat, however, give evi-dence of a milder ciimate. Hewondered i--F it would have been possible for nev ground ice to haveformed during Zone IIf.Referring to Dr.Ccopef s -tirst poi-nt, Mr.Ev3ns said that thethickness of drift over the Cheshire Plai-n is not cn the vholegreat, averaging 30-40 feet, and is i-nsigni-Ficant compared withthe overlying 2OO feet of collapsed strata on the salt crops;Dr.Moseley sai-d that in saliferous areas without drift there isa cover of collapsed mar1s. Referrlng to Dr.Coope's last point,Mr H"J.B.Birks said that there is 1ittle evidence that theclj-mate of Zone IIl ryas in any vay severe in Cheshire;admittedl-y.it grew colder, but organic mud deposition continuedfrom the earLy part o-t Zone I together with the pcllen ofthermophilous plants. Professor Shotton said that depositiono.f organic matter is no indication o-f climate; peat and organicmud frorn in Alaska^today in areas where the winter temperaturemay descend to.-50"C" In such conditions there is also aconsiderable amount of animal Ii--fe"19

Mr"Evans saj-d that one of the difficulties about some hollovs,particularly those in the Alsager - Crewe area, is that they appearto post-date an extensi.ve sheet of fl-uvic-glacial- sand which itsel-€overlies the most recent ti1l in the area; this is a basis forsuggesting a pingo origin. Mr,G"S"Boulton said that, oh the basisof extrapolaticn -trcm temperature data for the Lake District(ttlanley L959), i-t j-s extremely unlikely that perma-frost occurredduring Zone III times in the Cheshire Plain; any pingos wouldthere-9ore predate this period"Dr.K"M"Goodway quoted evidence -from Betley Mere: at one pointthere is a depth o.4 cver forty -teet cf peat and on the east shorethere are alternating layers c-€ sand anC peat, while one mile northeastthere are two hcll-ows, one smaII, with about six -teet of peat,and the other an area o.f Schwingmoor, similar to i^Iybunbury Moss,which may be rather deeper" Dr.Goodway wondered i-t these could berelated to -0au1ts parallel to salt runs. He al-sc aslced whether thelack of early peat deposits at Rodbaston could be due to the holIovhaving originated from sal-t -qubsidence at a late stage" ProfessorShotton thcught that it was extremely unlikely that there j.s .lriysalt at Rodbaston; the bog is mapped as being on Keuper Sandstone;morphclcgically it is an elongated oval Cepression" Dr"Goodway thenmentioned the curi-ous change of slcpe on the steep bank outside thebog both at \rriybunbury airC at Chartley; he vondereC whether thiscould be evidence that these two hcllows resul-ted -from salt subsidencerather than being kettle holes" Mr.Evans thought that hcllowswhich have fresh present-day terracing features analogous to landslipphenomena are 1ike1y to have resulted -€rom active subsidencecaused by salt sclution. Dr'.Iloseley conmented that there are verymany features which date from the last glaci-ati-on whi-ch lock veryfresh, such as morainic mounds and hcllcws; minor slips and hillcreepwit] have affected any steepish slope-< in Post-g1acial times"Mr.Land aslced whether any wind ercsion hollows might presentthe appearance of pi-ngos" Professor Shctton gave e detaileddescription of the supposed mcde cf crigin of true pi-ngos, and Mr.Poole said that wind erosion was ef.Fective on the Upper MotttredSandstone in the Peckforton Hi1ls and Hawkstone Prlrk area.Mr.P.Ilrlal-ton asked about the speed at which natural subsidencetakes place. Mr.Taylor replied that the rate o-€ natural saltsolution is determined by the rate of norrnal land erosion. Thefactor that would speed up erosi-on of the sur-€ace woulC be a lowersea level-. Professor Shctton said that about 10,0CL1 years agc thesea leve} vas 2O0 feet lower than at the present day; in theDroitruich area there is evidence of salt springs during the Uptonlr/arren Interstadial" iqr"Evans .said that basically sclution ofsalt depends on the access of -0resh water to it; thi-s does n.ctnormally ccme directly from rainfall but frcm the storage reservoirof the sands. Since there is no reason to suppose that the sands

have ever cornpletety dried cut, even during relatively Cryperi-cds, changes in the rainfall" vhile they vould have raisedor lourered the height c-t the water tatrle, would have beenunlikely to stop natural solution frcm taking place"The second questicn which the panel dealt with concernedmeans which exist -€cr dati-ng the inj-tiation of lcwland driftdepressions other than by deterrni-ning the age o-F the oLdestdeposits they contain. Dr.Moseley said that in dating glacialhollows in North Cheshire there is the probl-em of an apparenthi-atus from 2OTOOO to l-1,OOO years B.P" in which no databledepcsit was lald dovm. I.{r.Pool-e said that evidence of abandonedshorelines, for i-nstance those of Lake Lapvorth, can be usedto determine urhether a given feature dates from before or afterthe lalce concerned; there are exarnples of distortions of suchshorelines by coal mining and salt subsi-dences"A further question was rrrhy the Late-g1acial Pollen Zones I,II and III are so often apparently mi-ssing from lrrlest Midlandbasin Ceposits" l4r"\^Ihitehead thought that this phenomenonmight not be so widespread as is scmetimes assumed; certainlyZone II is well represented at Church Stretton" Mr.Boultonsai-cl that Zcnes i and fI are present near l/ybunbury and in theTern headwaters area; ln the latter locality the Zone IIdeposi-ts are overlaj-n by extensive sc-lifluction Cepcsits" Hemaintained that, when boring on potential sites, researchworkers c-€ten do not bore deep encugh to detect the earliestzones and it is far too often assumed that a mineral layer isthe bottorn of the organic succession, when it is quite likeIy tobe a zone rrr soli-fluction 1ayer" Mr.c.A" sj-nker said that j-nthe V/hixa1] - Fenns Moss area the Zone TV deposits cverlielacustrine sediments and further investigati-on is required"Dr"Goodway thought that Professor Godwi-n had detected Zone IIIin Miss E"M.Hardy's pollen s1j-des frorrr tvthattall Moss, Shropshire(cp" Hardy r939), and he reccl-'t-ected seeinq this mentione-d'TheinHistory of the Bri-tish Flora' (eodwi n- 1956) " lIr. Landemphasised that the absence of Zones r to rrr is more apparentthan real. Dr.coope poj-ntec out that extnesi-ve zone TTr sorifluctionmight have been the cause of clrainage impedi.ment, thuscreating nev sites for peat development after zone rrr whichcould not of course contain any Late-g1acial sequence. Mr.Evansremarked that such soliflucti-on would produce shallow hollowsonly. Dr.coope replied that he believed that the peat-fj.1Iedhol-low at i?odbaston coulc have been formed in thi-s r/av.Pro-tessor Shotton said that the problem was connectecl- with thede-tini-tion of Zone I; for instance at Colney Heath it vasl-4,OOO B"P. and in the Lea Vall_ey 18,O0O years B"P" Dr.Coopedrew attention to a radio-carbcn Cate o-0 2B,OOO years B"P.derived -from material whj-ch was probably laid clcvrn before thelest major ice advance; he saiC that it is 1ike1y that fcr thegreater part of the past 28,000 years the climate has been tcotl

cold for organic material to be deposited" Pro-fessor Shotton'scomment tfrat the great problem is the apparent gap between 20,OOO(or earlier) and about 12r00O years 8"P., from which there are no\v+dafel-rro dann

SESSIO}{ TII:CHE}II STRYChairman:Itapporteur:DiscussionD" J. Bellamy, The University of DurhamK" Thompson, The University of DurhamPanel-:H" M" Grimshaw, The ldature ConservancyDr. H" Iq" Hurst, The University o-F LiverpoolF" J. H" Mackereth, Freshwater Biologi-calAssoci-ationDiscussionPanelIdater and peat chemistryOpening the discussion, 1"{r" Bellamy defined ecology as thescience vhich deals vith the causal relationships between the bioticand the abiotic components of ecosystems" He pointed out thatthere is already much evidence indicating that Cistinct correlationserist between the vegetation and the peat and water chemistry inmir^o 6rr..c\/cro'ns.eevej' J uvr The genetic sequence of mire type developmentic !J s : h"int-in vavLrv r1lyrocess regulated by the sbrage of energy (depositionof peat ) within the system" As a resul-t mires represent aunique situation -for the study o-0 the control of succession, theproducti-vity of a whole range of florj-stica11y distinct, y€trelated ecosystems in relatron to mi-neral supply and mineralcycli-ng, and the peformailce of particular species in relation tothe suppty of nutrients, for exanple phcsphate"The panel vere asked how they urould extract mi-nerals frompeat -0or analysi-s" I"1r. Mackereth pointed out that peat acts asa cation exchanger and anions also tend to be held by ferrichydncxide" There seems to be li-ttle point in transferring minaralqfn rrot another exChanger during the anal_ySiS. He suggeStedeluting ions directly from the peat" Dr" Hurst was Cubi-ous asto whether i-ons would come off easily into water.Mr. Grimshav recolnmenCed ammonium acetate extraction foravailable ions, and Mr. i"lackereth ashi-ng with perchloric acid fortotal ions. It $/as decided that, dependi-ng upon the aims of theinvesti-gation, both techniques have their applications.

Another question concerned the methods -for measuring bicarbonatein peats" Mr. Mackereth recommended srveepi-ng out dissolrred CO, from-the peat extract, acidifying and collecting the CO., evolved" Headrri qed aoai nst dif fusion tcchni cues " Dr" Hurst S.slced why -' --J it wasconsidered necessary to determine bicarbonate" Agreement rvas reached+lnr+ -^ iro qti-l 'lnn'l rr qoF)lci no nrlr. r-o: r.al at'j nnq - i |-i q nar hanqL.IId,Ll d) wg ('1rs JL!rr vrr!) --------J -\JrrEraLlurrJt rL rJ yErrrqt/Jbest to determine as many ions as po-qsible.' Mr" Grimshaw said that atomi-c absorption determj.nations o-F magnesiumare more reliable than versenate ti-trati-ons, provided thata suitable buffer (e"g" lanthanum chlorlde) rs used to overcomephosphate interference "On the questicn of sulphate and chloride determinaticns in peats,Mr" Macl

It{r.Be1lamy said that an instrument for continuously monitoringconductivity has just been brought on the market; it can beused in conjunctj on with a data-Iogger, produced by DobbieI{clnnes (Electronics) LtC"The question was raised as to whether the high j-onic concentrati-ono-f the water in most o-t the Cheshire and ShropshireMeres renders the ef-fects of local fertilizati-on or other chemicaltreatrnent of the land negligibte by comparison with itse.f-fects on vaters of Iow base status" Mr.Mackereth menti-onedinvesti-gations by Edmondson on Lake tniashingtonr U" S.A., whichshowed that, if phosphate is added to the water, it can be detectedlater in the sediments "Dr.Pritchard asked i.-f the quantities o-t fertilizer appliedto land comprising reservoj-r or lake catchments coul-d not bemore accurately calcul-ated. Mr"l{ackereth repli-ed that, -trom thework of Dr.J.W"G.Lund and himself on Stocks Reservoir, somecontrol of the ef-€ects of -tertilizers seems to be -feasible, forfertilizer applied tc a fietd can onry ':e detected in the run-offfor two to three weeks. So, if phosphate is apptied only atthose times when the natural -Flora and -tauna of the lake areunable to utilize it, the effects of application should be keptto a minimum. I'ir,lrl"c"Morgan pointed out that lakes with largercatchments, such as Loch Leven, maintain blue-green a1ga1bloorns owlng to unusuall-y high nitrate in the water of in-tlowingstreams over long periods" Thi-s could indicate that differentfertilizer treatments, different land uses and differentamounts o-t rainfall can vary the ef,tects of fertilizers. ylr"Mackereth still- insj-sted that in all cases it shouid be possibleto minim.ize this type o-0 pollution by controlling the time andrate cf apprication of fertilizers" i'Ir"Be1lamy emphasized theneed -tor extensive research intc the e-ffects of fertili-zers onmeres and mires, especi-a1ly those viith oli_gotrophic waters"It was asked what dlfficulties domestic pollution (as inRostherne Mere) and industrial pollution present to thechemical analyst. This provokec little discussj-on and it wasdecided that pollution presents lrttle problem to the analyst,but the interpretati-on o-t the resul-ts is often rendered verydifficult "During discussion o-0 the increasing use cf the Meres forrecreation it was concluded that the effects on the natural-€lora and fauna are unl-ikely to be in any way as sericus asthose of domestic and industrj-aI pollution" I,/ater-skiing rvasnot thought to have a si-gnificant sti-rri-ng action" In -tact theoccasional event cf jettisoned oi}, altering the water surfaceproperties, is probarly as serious a problem as is likely tobe encountered for the moment "'2 -\

Dr.M"C"Pearson a-qked to what extent lateral or verticalmovenent of icns takes place loth withirr and between sediments,for e>rar-pIe peat and clay" Mr"lt.ecriereth rnenti-oned thatVivi-ai;i-te (-ter.'rc'us phosphate) nodutes are sometimes -formed by;iii-g.natio.r oi i,c:,t -,i,'ithivi lcwer lake sediments" but that suchmigration Cc:s nct risually occur in the nore recent lakedepcsits. He sriq_qes-ced that, whele mire peats are subjectedto vater moverilellt or fl-ushing" o]1e would expect an ionic..ct;i I i l,r-,::r- ev,,1 '*i gYelrran:f i.r.,rYr q Lrv;- vr ni i rv:rJ onS:teoneentfatiOn uvrruO-f iOnS in!r^ ^"'^.. " -:atsLIi j '5L,ta f dLU _t- is, no doubt, cormcn eno,-tgh"ijr.G.i'" loc'l.iar.. p;:inted cut tl'-at green lea-fy shoots ofEriopllcrr)lr vagri trtr;.n: plants contain 30 tjr?r3s nore phosphateanA )alTf,i,:s*ritlle f,ota.::ium thair did t.tie peat at I -toot depth,whelcas d-'inc cr" r'ecencll' Ceac lrraves ccn:aj.n only B-9 timesn;cre cI ti:sr.: e,enar.rts" A -ci-milar situatio;r exi-st.s for_+_:q1rgr_,_sjiI)_l_i:T, iulr" Bel-l amy sr-'gges c :ci that the phosphateProb?b--y rro'.rrjl reaves tlie plan:s" Lut is retaj-ned over a longnc'r.''i nd '.r-:-: i^i-,- - -:i r - l c. r^.1 nriO 't-t"ans.,.e:.- -,!r.brr-,+!u-.vrrL J) 1.! urrJr vr g1'169 tO the tillef S inSr-t..,te S jirr:: i'e:-"S'rl:: -,he-::hood cf saline contantr,tation of the water inlij.- - 'v-rs r-e-it :rc":I-si-c':':ed- ej thcr: d;-r'eci1y !r'on -su-badjacentsaii-feroi,.r b."-.; a-)-. -flon Klit:t-.:" rr,:teiji:l- -incorporatedi-rrclregl aciai C: i f t " l',1r:" C../r,. ::i tiher q,-toted Goi'ham,s (1957 ) commentthat t.r3 cl"ioridc ccvrle.irt..-rra -sererial neres is about six timestb.:t of Ta--ir.-;aier. rYr"D.H.I,alrd :;aid that typical ground vaterin 1-h.is regai:11a3 a chiorife ccntent of 20 to 30 ng/t ofciitc-"i-cle (as- --" anu that concL-,4.t1-ati-ons in the tneres of thisorder ca:enot thcre-ic:e be regarcred as r.rnusual; the meres are\-; -.^ y.h-21'r.- .--rlon "--i-i c He tl:ouoh j .Jtr.a1- Saf ine CCntaminatiOnfrom (errpcr' :naterral- i-s inicrobable dri: io leaching. Mr..D"Ittaclcn._';' cc"i':_r'm:d that the exciiangea,;-re soOium values, even inthe lrver ,-:iiz:ns oi sr:i-ls ,:leveloped in Keuper marl orrel-ated Cri--f i,:; ? are generaLly .;er7 iou j ndeed. Dr. F. D" C " Henryaskeci rf the couse of the relatively hi-gh salt level- in themeres coul-d be evaporation anC rvhether evaporation pans couldbe u:eo to c]eterrrrine its extent. It vas decr-ded that concentz'aticnby e.rapolaiicr, is unlikel]r, ano Dr"J"V" Sutclj--tfe addedthat, in anll cf,se. evapcrLrion pans cnty dcmonstrate the rateoF evapora-;-j-:n -fi'o;'n er,;iporation lrns: tirey can hardl-y benWnor.]-nd-n,:-i i -k'ir. +- ,'-*--dDI)r 16' S"j-]rtU-Laj,-.,,1rfo -- n- ii]yrt-i n.tr^ CCOSSeS "Fj na-Iy, i cnj c anal-;'s,ts 1,Icrc dis:ussed, and it was agreedthat a decisicr, regar.dirrg '.ihich analyses are essential- is, asYet, lirgely l.ersonal and dependent cn Lhe ierms of reference.of each partj.cr"ilar lnvesti_gation" Ivir.Maclcereth suggested"irosphate anci nitrogen, 3S these a.re essentiat to iir prants,althouSh rrot necessarrty limiting their distril:ution to aparticuiai" hal;itat. !1-'"Grirnsha$r ment-oneo sj_lica in connectionwi[]' the distrj-buticn o-F diatoms. but i-t was argued that,t\)

even here, situations are likely to be encountered. i-n wlnichsilica is present in abundance but some other essential ion islimiting; in fact anlr g5sential element, even a trace element,can be Ii-miting in theory. Dr"Hurst advised that one must-first work out the tolerance t-irnits before deciding vhich arethe most important ions to study" l4r.Bellamy pointed out thatthe mere -fact that a plant stores sornething is not in itse]-f anadequate reason for supposing that it needs it; -ior example$piiagnum Faqg,}laniaum stores considerable -quantities of cobalt.He sai-d that we must first deci-de which are the most inportantplants to work wi-th and then measure their performance indi-t-ferent condition5 . in the -f ieldo_ -Mr.Bellamy concluded the sessicn by briefly describing hisworl< on the classification oi European mires" He showed thatthe rnires could be grcuped into seven vegetaticnally andhydrologic+lIy distinct types ranging -from those with watersrich in Ca-- and HCOq- ('fens') tc those whose waters are richin H+ and SOa-- ('Urinket bogs' and 'raised bogs'). Heemphasized that icnic ,'nake-up of the mire waters, rather thantotal ionic concentration, appears to be the i-mportant -tactoT.He also demonstrated the incrbasiirg importance b'" C1- and na+in mire waters with decreasing distance -from the western s€dboardo-f Europe and discussed possibl-e ecolcgical irrpli-cations.He again emphasized the importance of such empirical ecosystemdata The aim is to explaln the phytosociology cf mi-res interms of water and./or peat chemistry and to test these correlationsby autecological studj-es bcth j-n the field and 1n thelaboratory"27

SESSION IV :LAND USE HISTORYChairman:Rapporteur:Speakers:C"A" Sinker, Pield Studies CouncilD"Pannett, Field Studies CouncilD"Mackney, Soil Survey of England &B"R"Ha1I, SoilSurvey cf England &A. H" Fitton, National AgriculturalAdvisory ServiceJ" B"Lawson, Shrewsbury SchooltdalesI'/a1esA pedologj-ca1 approach to mire problemsD" MackneyAround the lowland bog sj-tes in glaciated landscapes o-f North-\dest England, soils are conmonly distributed in recognisable patternswhich depend mainly upon the nature o.f parent materials and presentand/or past hydrological conditj-ons.In clayey materials surface-water gley soi-ls predominate and,in the lowest positions in the relief, pass progressively i-nto peatysurface-vater gley soi-Ls, peaty ground-water gley soils and peat" Incontrast, sandy materials are associated with sandy brovn earths andhunus-iron podzols vhich, in lover topographic positions, grade intohumus-podzols (gley podzols), sandy peaty ground-water gley soils andpeat.Soil materials underlying undrained peat are usually permanentlywaterlogged and thei-r grey or blue-grey colourations are attributedto the complex, imperfectly understood process referred to as gleying,by which ferric iron compounds appear to be altered to -feruous ororgano--terrous complexes. Tn clayey materials there is probably1ittle vertical redistribution o-0 these components, but in sandymaterials it can be evident that organic matter 1n particular hasbeen translocated, a fact which may be di-€ficult to explain in relationto present day hydrological conditions"Accounts o.f conditions in Europe and Canada t:y Tarun (rglO),Damman (rggr) and van Heuveln, Jongerius and Pons (rgeo) have abearing on the apparent anomalous association c-t podzols and deeppeat. From these papers it is possible to extract evi-dence suggestingthat such soils could have formed 5efore, during or after themain period of peat formation.Soil po11en analysis rnay provide evidence o-f past changes o-tvegetation anC is probably more relj-able than interpretations o-0such changes based on correlations between the present vegetationand soil typeZg

Th-e -i-e-qlamati-on .and exPloitationi-n Lancashireof moss-+andB. R" Hal1The lowland peat deposits throughout Lancashire have beendivided into t$/o stages o-€ development, lovr moor, consistingmainly of reedswamp, carr and -fen-cam Peat, and raised mossta typical profile of which sh

cattle remove-s.'most o-f the'coarse grass,-in prepara,tion. . -for seeding; the cattle also compact the surface soil andtread the peat avay from the shallow roots o-€ the birch trees,causing their premature death" Ground rock phosphate at therate o-f 3O cwt" per acre is applied by hand, folloved by along 1ey seed mixture broaCcast on the surface, usually inlate spring when the natural sward has been su-f-tlciently grazedand trampled by the cattle" An inter.esting point is that satis-factorygermination o-f, tire seeds vil] only take place in thepresence of phosphate. Ground limestone at the rate of 6 tonsPer acre is aPPlied during the early stages of reclamation" Eachyear the improvi-ng srvard receives a spring dressing of 4 to 5 cwt.per acre of a compound fertilizer" Gravitational drainage bymeans o-f 3inc-h tit-es is undertaken usualfv six vears a-fter enclosure,the ti-t-es beins taid 4i-i;;t--d;;;-;i'i."i."irJri"or 21 feet.The area is ploughed after nine or ten years and is, from thenonwards, uscd -fo:l intensi-.,re alable farming. Thls method ofreclamaIion is re]-atively cheap, though ]ong-terrn, and can onlybe practised where the pattern of farming j-ncludes both li.vestockand arable"The seconci nethod cf reclamation is known as dir:ect cultivation"ft is rapid, producing arable crops vr:-thin trrro years, but it isextremely costly and often requires expenditure in excess of €1 OOper acre" A rcut off t ditch is first constructed around the areascheduled -for reclantation, substantially reducing lateral watermovement from the main body of the rnoss. o:-tclies are then cut7 {."Ideep at 3o foot intervars by meanc o-f a mechairical d;ggerand they are le-it open -for twelve months to a1low initial- folsof water, shrinkage and consolidation" After this period, theditch bottom is regraded and 3 inch tiles are l-aid and coverect"Grounc l-imestone at the rate of B tons per acre is applied to thesur-face and this is rotivated in" 24 ctr[. per acre of a compound-fertilj.zer are then broadcast and potatocs aie planted. Thesubsequent crop is spring whcat, under-sc'r;;'lLrerrd a-€ter the third yearthe land goes j-nto the normal_ farm rotation". With improved drainage and intensified cuiti-vati-cn, the reclaimedmosses are gradually v/,st]lg away due tc processes o-f oxidation.More catastrophic rvas the removal- of peat in the past for fuel;large areas have been cut over, often rvith complete removal ofthe peatr tle only evidence norv of the former cover bei-ng the humosenature o-f the sur-0ace mineral horizons rrr-th strongty gleyed profiles.Peat-cuttinq for domestic -0uel is norrr only carried- out in local-J?ed areas Di individual -f armers " Conm,e:rcia1 cutting for the mosslitterindustry, on the other hand, is being carrieci but on severalraised mosses at the present day" The pr-ocessed peat has manyuses, for example in irorticul-ture, the rrrhlsky indultry, -fish-curingand coal gas purifi catron ano as deep ]itter for pourty.en

parming-oF-Lancashiremossiand - past and presentA. H" FittonBaines (t8:6) observed that mosses were characteristic o-tLancashire but vere then rapidly being cultivated. Chat Moss'west o-t l"lanchester, appears to have been one of the earliestmosses brought into stable cultivation"The farmlng pattern of the mosses haq been and stil1 isprofoundly influenced by three prlncipal- factors. These aredrai-nage, the stage of break-down of the f rawf moss and theapplication of lime. Many early drainage schemes $/ere ruj-nedby peat shrinkage, so that punps had tc be installed, vhi-]e-further wastage has since brcr!€ht the surface down to the levelof the buried drains so that deeper drainage systems have beenneeded" Early paring and burning also damaged the soil qualityand 1ed to disappointing results" In general the pace cfreclamation was for many years kept slow by the problem ofoverland transport of lime and marl, which is by comparison asimple matter tcday.Three other factors play lesser but important parts in thefarrning pattern o-F the mosses" First is the fact that theybecome very vet and boggy under conditions o-f prolonged andheavy rain, and .farming operations become difficult" V/i-nter-€rosts fift the land excessively and can disturb vi-nter grain;the main crops are therefore spring-sown" Growth on themossland is very quick and vigorcus once the land has varmedup. Fina1ly, weeds u/ere once a sericus prcblem on recl-aimedmossland, but these can now be ccntrolled by sprays" Potatoblight is more conmcn on mossland that cn other soils in thecounty, as the local condi-tions are mcre -favourable to thedisease, and aerial sprayi-ng is now colnmon"The usual rotaticn of crops on the mossland includes oats,maize and pctatoes on acid soils, but liming al-Iovs a widerchoice, i-ncluding barley. It has been fcund by experiencethat crops such as barley tolerate a lower pH on a moss thanthey would on a mineral scj-l" Grassland and 1i-vestock arerelati-ve1y unimportant, perhaps cwing to the di-fficulty ofestablishing satisfactcry and persistent grazing swards"3t

Historical investigaticn of lowlandbasin s;.tes in Shz.opshireJ. B" LawscnOnly the introductcry volume cf the Victcria County Historyof Shropshlre has been published (eage 19C8), and detailed researchhas not yet been extended into the north cf the ccunty,but -fortunately good ccllections of estate records cover themain areas of meres and mires anC are avallable for future study"Those of the Duke*q o-f Bricigewater cJver the most i-mportant areasaround Ellesmere and V/hitchurch" There are alsc records forthe extensive mancr of tr/en and varlcus manors sumound'ng theWeald Mcors, includi-ng the Duke of Sutherland's estate and theMoretcn Corbet estate"Medieval records are generally pcor in topographical detail,but material from 15OO cnwarCs provrdes a clearer picture. Rel-evantinformation on lcwland basin site-s is }ike1y tc be found -tromthe folloving classes of document:-1. Surveys: mancrj-al surveys l-ist tenants, land and associatedrights and customs,2" Court rclls: Presentments at manor ccurts may j-nclude thosefor turf cut cn cclnmons,3. Custumals: rights and obligations of tenants rarel-y mentiontur-f .4" Accounts: medieval manorial acccuntsrnar.oi nt rOll S mav i !r!e!4 nc'l_Ude * USefUl 4JUr U! daf gqLq a" oand later rentals and5" Maps: e:tate rnap! begin about 1j5O; tithe maps (showi-ng aIIland subject tc tithe) fottcw the 1835 Tithe Cbmmutation Act;j-nclosure avrards anC plans foll-orv Private Acts and agreementsduring the 18th century"- fn ShropshLre, the greatest period of landscape change appearsto have been in the i5th and iTth centuries when increasing dbmographicand economic Pressure led to the cultivation of maiginallands,the exPlci-tation and cl-earailce cf natural urcccllancl and theconsideration of eimprovement' by drainage. Fcr the same reasonsagricultural speci-alizaticn appears tc have taken place and by 1600the county was noted -Fcr its ce^ttle and clairl' pr:clucts"rn North-vilest shropshire, in the viciriity of the meres andmosses' despi-te 1zt]n century expansicn, there vas Cense -€orest untj-Ithe early 16th centurlz, but between 1550 en,-r 155C thcrc iyas r.lpidclearance especially in \"trem, M.rdrlte (Gough 187 j) and \dhitchurchLordships, which was accelerated by the demands cf eager l-andlord.swho encouraged glassworks in the fate 15th century anb sold wocdto ironmasters from the late 162Ots" The clearances provicled

new pasture and wj-th j-t the need for niore wj-nter -feed andconsequently for meadoui 1and" Manrs attentj-on thereforeturned to the inhospitable mosses as a soul'ce both for fueland for meadowinq"Except on the dry barren Peatl-ands rffest o-0 the \niealdMoors, turbaries appeaf to hatre been an exception in themedieval peri-od, fn about 1540 Leland -qarv them at MarburyMoss in Cheshire and at unspeci-fred praces nearer Shreiirsbury(Toulmin Smith 19o7-1o), possibry at Edgebolton, where therewas a turbary in 1582" Cutting had begun in the area o-F .ir/em Moss by 1550 and at Brown ivlosse near Vihitchurch, by 1572;the pools on the iatter' site appear to have been caused bydenudation o-F the peat to drift level" Tirere seem to havebeen no major schemes for recl amation before 1602, when thedrainage o-f Tetchill lvioor commenced; 45O acres out of 75A]rad been recl-aimed by 1621 , when the land was being used forcorn, grazing and meadowi-ng. The Earl of Bridgewaterrs agent,Mr. Gosse, reported that j-nitial drainage here caused themoss to shrink at least a yard" The remaini_ng area \i/as regularlylaid out as a turbarlr for aCjacent villages tn 1634,Similar drainage projects vere on hand on the Weald Ploors inthe same period (Hiff 1953). Fir wood stumps and trunlcs werenot infrequently found in the mosses: Leland noted them atMarbury Moss and in mosses in shropshire (touJ-min smith 1907-1o), -and they $/ere also found at Bdgebolton, on the edge of thev/ea1d Moors, in 1582 and on Dudleston Heath, near osveitry, in1602, vhere oaks were arso discovered rn the peat (srack 1g>l)"By comparison vrith the mosses, tire meres were much lesssusceptible to exploitation, except as fisheries, and informatioirabout them is scanty" rt is clear that two forner meresnear Ellesmere,_ norv Pikes End Moss (pykelsmere in 1302) andwhattall Moss (sinker i962), have changed by naturar successioir;at the tatter site a dug-out canoe, probably of the earryfron Age, \yas found at the base oF the peat (Ctritty 1927)Drainage has also taken rts to ll- where ccnditions were su j-tabIe.Between 1553 and 1619 a pool o-f 2co acres near rdem (in theregion of Lower Pools Farm) vas drained arrd converted. to meadow(Garbett 1818), and a srnalt-er mere cal-led Haremeare (eough1875; now Har.mer lr,ioss) was dralned betr,reen TGOT and j64O"Myddle Pool, near by, sr,rf f erec the same f ate for the samereason about 1600 (Gough 1875), and, near shaurbury, set (o"Si-de) SaOOte Lalce and Culter.siche poot (nov Ofdpc6i) werealso drained"The eff orts o-f the 15th and 17th centuries stit_l teftcertarn areas untarned, notably Baggy l4oor, north o-F Ruyton,and vihixall Moss; the former vas dealt with by a successiono-i Acts o-F par.tiarnent in 1777, 1783 and 1861 aLA the latterby an arvard of j823, but onty o]t Bagg;r Moor has land use reallvchanged33

The following; manuscripts provided ,rruch o-t the informationgiven above without a reference to published worl

indicators promises to open up neu/ ways of studying soils 'and their past vegetati-cn somerirhat alcin to the establishedmethods of po11en analysis.F{r" J" l"Iil-es asked u'hat the time }ag would be betlreena change i-n vegetation and the development or degradationof a podzol" Mr. Mackney of-fered background in-formationof relevance to tire question by saying that datj-irg by thecarbon 14 method of the humus in B horizons of some Brecklandpodzols has indicated tha podzolization comnlenced inthese -sorl-s at ]east as early as 2rB5O B"P. (Perrin, tl/ilIisand Hodge 1954). Other sur-faces sealed under Bronze Agebarrotrs -shor',' that adjaceirt podzol-s rnust have developedsince (oimbreUy 1962)" rn Lheory, tire whole history cfvegetation changes on a si-te could be recolded in the under-I v-ino qoi'l nrofr-r i1e.Mr" Sinker consjdered Shropshire well o-ff at present -torsources of historical- ivr-fcrmation. He said that not onlyis there arr efficient County Record Of.nice, but work on anew Victoria County History is in progress; but he wonderedwhere it is t-..'est to seek such information in other counties"Mr" Lawson said that generally the frrst place to enquireat is the Couiity Record Cffice. The materi-al availabledepends on the lucl< o-f survrval, dnd one must always beprepared for di--qappointments" One :nust also real-ize thatdocuments were orrgii:al-Iy made for purposes other than thoseo-f direct interest to the resealcher and hls most val-uab1einformation nay sonietimec con3 from, -ftr exampl-e, a passingcomrnent in a legal- a:igumer-rt" It{r. Sinker commented thatthe ecolooi -ct mrr-st learn to aqk ihe richt nueqf ions of thehistor.jan, a;ld Dr. B" H" Green -saio tliat an exampte would beto enquire aft--r' the docunentary evidence of subsj-dence causedby salt uiorkinq.Iuir." P" H" Osluald saio that terminology can bring aboutmisunderstandings of histcrical records" For example, yapp(.1952) has pointed out that the passages in Letano's Itineiary(Hearne 177O; Tor-rlmin| ^ ^^^ \ -Smith 19O7-iO)-supposed by Tans1ey(1939) and many otkrers to re-ier to -firs grcvrng in Englandiir the early 16th century ('fymes', rfirues' or 'fyrrist),as to 0il lPposedvood dug ouL orc peat bogs, dctually i:elatero iurze (gorsej"Dr" K" M" Goo

eing sold from t"ladeley Great Park at times during the 14t11century" On the other hand the fact that nLost of its arealies on Bunter Sandstone and that there i-s deep Peat developedin places suggests that Fraxinus j-s unlikely gvel to havegrown trere. ivir" l,awson-SaETTat examples of thi-s lcind ar'erare. Mr" H" J, B. Birks then mentj-oned that tnanors inCheshire were once required to grow -tlax and hemp; whilemaps and surveys indicate small yarCs suggestive of productionon only a domestic scal-e, the flax and hemp pollen found inpeat in some places suggest that the scale of proouctionwas, at least loca11y, far larger"

CLOSING SESSIONChairman: Dr" Torn Pritchard, The Nature ConservancyDr. Tcm Pritchard:t'Without a doubt I think tkrat the main ob;ective ofthis ccn-0erence has been achieved" \de have been able tocliscuss very thoroughly a number of complex technicalproblems and to obtain some answers, and in other casesve have been told that no ans$/er can, as yet, be found.- tt\fe have, I think, also achieved something else. l,Jehave achieved a greater sense o-f purpose - achieved, Ithink, the foundation of further development and co-operatlonbetween people in different fields" Talking to variouspeople here I certaj-n1y have had a strong .feeling thatthey do want to have adequate foIlow-up procedure to thisconference and to keep in touch with each otherI'f arn novr goingI to sum up.rgto ask the Chairmen o_f the SessionsDr. M, C. Pearson(Chairman o-f Session I):'r!fe have covered in qcme detail- a wi-de range of topicsin the Hydrclogy sessicn, but r shal-r restrict my remarksto some of the more important ones which should receivespecial attenti_on in the future.rrI think we have reasonably clearly defined what wemean by the water.balance of a mire system; in partic.-ular the iirput ve defined as rai-n-tail plus- sur-face andground-water inftow anc thc output as evaporaticn, transpirationand surface and ground-water outflov; anydi-tference between them is due to a change j_n stcrage"otWe have al-so discussed some major questions relatingto techniques, These have lnclude.d the Ci.-fflculty ofestablishlng catchment boundaries, the vari_able natureo-F the sedirnents (which mal

"One of the.- thi-ngs that kept cropping 9p vas- the lacko-f de-finition of th6 questions be:'-irg asked by the biologists"Until we define our questions aqcurately we5bviousty cannot find ccrrect allswers" f suggest thatx/e shoul-d define the questions ln the -iie1d first and-Fo1low them up with fiel-d observati.ons and measurementsand ]aboratory experiments; - only by experi-mentation willweinspire confidence in cur fleld cbservatj-ons.erI must thanl< the specialists rvho have made contributionsto the Hy

..avtr-a-nvtimrrvL,rr,L-gr rrrrrvcar-rlnrlir'>l m2Tre 1^^*-^ -i.-\-lc\-/-LL,\J J\,ar lltclyJ inr-h m;l nq c,lFt Y./C rlc.vc > l-/\--Lrrurr lllayJ vrthe whote ccuntry at Leed-q Lylc in Lcndtn, and theseare open tc publrc ri'ispecti:n" On the questj-on ofiirsburnentation, parti.culariy cf ground water, Mr" D.A" Gray, head cf clir '',Cater Department, asked me to saythat he wculd be quite willinq to discuss i-nstrumentationrvith you i-f -it rvould make any contribution tcward.ssolving you-r prcblems o t"\"Jhether any big lntegrated research tcpic vi11 crmeout of this confer:ence remains tc be seen, but we shouldbe interested in j-t and f hcpe that i)ur efforts woul-dget support frcrn other quarters. Geologists thernselvesdepend, especiall-y in problems c-f thi-s scrt, on cooPeraticnfrcm other scienti-qts. riMr. D" J" Bellarny(Chairman of Sesqion III ):ttI must stress the importance o-f the discussicns vrehave had. I ryish I had had the opportunity cf attendinga meeting li-kc this before f began my research; itwould have sa-red rne a tot o-t time and rvorry.Itf feel that the follorying conclusicns (ii such theycan be called) cair be drawn from the drscussj.ons o-t theChemistry Session. First, nire ecclogists have got alot of hard worl< to do; long-term, regular chemicalanalyses are nece*qs.a.r"yr and these rnust go hanc in handwith metecrological and hydrclogrcal studies " We musttry to begin tc understand the ecological effects o_fwater flow" Ramman (tglt ) stated that ftolrlng wateracts l-ilce an increase of nu-trlent*s. Does rt? \{e nourknow that we are not wasting cr:,r time; we have thetechnioues to cbtai-n the data to answer the quest.i cns.?'f think it woulC be vorth considering the setti-ng upo-t a joint resear.ch pr.cject tt col]ect all the necessar.ydata -frcm one si.te" It wculd of course ccst a lot cfmcney, but r think it would be niclrey rve11 spent becauseit would glve us a ba_sic po:nt o-f reference once and fcrItA major problem facing mankind tcday is that ofthe rnaintenance of agricultural prcductivity in relationto mineral supply and minera1 cycling" If we cangain a fuI1 understanding of the reconomicsf of a naturalecosystem, then the findings can be applied to man-madeor managed systems" I believe that mire eccsystemso-tfer the best cpportunities -for gaining the necessaryinf ormation"*'39

Mr" C. A. Sinker(Chairman o-0 Session It/):rlfn the previou-s -cessions \I/e \riere given some idea ofthe k:-nds of facts, principles and techniques which areavailable to the ecolcgist who is faced in his researchwith questicns o-t hydrclogy aud chemi-stry" I am ccnvincedthat in several c-0 the -fundamental problems t-nvetland ecology prcgress can only be made through the ccordinateci.e-€forts of ecolcilists and other environmentalsci-entists "'rln Sessicn IV we have heard scmething of the in'oormationwhich rnay be available -0rom the mineral soilsaojacent to our basin sites; we have had acccunts cf thereclamati-on and use o-f the Lancash:-re mcsslands - accountspacked wi-th valuabl-e material which vill ccme to full usewhen we turn to the as yet unstudied reclamation histcryo-fl the West Midl-and sites; and rve have had scme very usefulpractica] tr-PS on horv to -seek the r:el-evant data .from survivinghistorical documents and horv tc interpret them rrhenwe have got them" It may appear that the present sessionhas lacked the thematic unity vhich marked each of l-ts predecessors,but f believe that, for all their -tascinatingdiversity, the four tallcs ve have heard had a common anddual thsne running through them: in the first place, theyilluminated for u-" the dimension of tirne (a vitat dirnensionoften neglected by the ecologist for want of informatron)and shoved us the scurces and kinG of data available; inthe seccnd, they underlined the ever-changing irnpact of humanactivities upcn wetland habitats"'rlt seems to i'ne that pecple in these other disciplines(pedology, agriculture, tocat history and sc cn) can beespecially use-0ul- to the wetl-and ecnlnoiet'in the -foltor.rin3riays: -1 " by helping us tc seek ano interpet the retevailtfactual information cn the past ]ristcry cf si_tes,supplementary to that which 1s buitt into theirstratrgraphy;2" by throvi-ng the light of experi_ence on problems ofwetland matrag;ement, especially -fcr the conservationistconcerned with del_icately balanced eccsystems;3" by guiding us through the vealth of pi.acticat_ knowledgeabout organism-envj-ronment relationships whichgenerations of agriculturi_sts and cther appliedscientists have iccumulated. At last, anb none toosoon, tle ecologist i_s comins doryn from an ivorytower whose wj-ndows all faced a\r/ay from agriculture"40

'?I have been lucky enough to be invclved rvith boththe l.{eres and Mir'es rResearch Groups frcm thej-r inception,having a str':ng personal interest in many o-f thehabitats and prcblerns wi-th which they are concerned"As i'Jarden of a Fiel-d Centre my fi-r'st concern is withenvironmental educati-on, and in the Field StudiesCouncil- we talce the lanCscape as our raw material-€or teachiirg" \^/e try as far as pcssiblc to teachfrom the whole landscape, in all its aspects, and thiscrrnthaJ. i r. rr)F.Yr:r1r-h rhv , -.^-'cws uf a great variety o-f -€ascinatingnelr ideas and poteirtial research probl-ems. Italso highfights the enormous gaps in our corporateknowledge of the envlrcnment " I have -f ound theopportunities for discussicn pr.cvi-deC by meetings o-fthese Research Groups very relrarciing indeed, and nonenore so than the present multidiscipli-nary ccnference,I should lilce to conclude by palTrng the warmest complimcntstc Tom Pritchard and Phitip Osvald, not onlyfor arranging the present occasion but also for makingi-t such an outstandinq success"ttDr. Tom Pritchaz:d:tr.f think that cornmun:-cati,-on is one of our biggestproblems in science tcciay. Before \r/e can hcpe to fillsome o,c thc-qe b: g Japs thet you have referred to, thefirst step is tc make sure that we are arvare of all theknowledge that is -€1oati-ng ar.ound in this country andin different parts c-t the vorl_d"?!I menticned at the beginning of the meetin3 that Ithought this conference irias tn a $/ay unique ancl, havingnow listeired to the papers and Cj.scussion, I am more thanever ccnvinced that it is uirique in at least truo respects.It 1s PC.ssibllr the -fj-rst ccnference to bring togetheisuch a broaci spectrum o_0 specialists rvho are on the-€ringe o-t the someurhat rndef Lnabl-e prof essicn of ecology.ft is also uni_que in that i-t is thc first meetj_ng atwhlch sclenti-sts rarom a.r -r- but one c-f the componentbodi-es o-f the Natural Environmental- council have gottcgethcr. l'/e have nct heard very much as yet o-f theachievements of the N"E.R"C; it is sti1l a very newtrorlir far-kl rrr an r:rrfr.'ama-l rr r.nmn'linrfarl crrlrinnluvuJLquJ\! qrr v Lr u,,rv4J, --u Le(I SUDJCCIsure that rrost people are verj/ pleased with the initiativeo-t the gcvernment in gettiirg this new Research Councilg9ing" It is in principle an excetlent concept and, Ithrnk, a breakthrcugh'for maicing progress with much ofthe research lre in the ccnservancy have been j-nterestedin for such a long time"41"fam

I'This conference rr/as not convened by the NaturalEnvironment Research Council" Tt emerged, sc tc speak,rfrom the peopl-er" It came about as a result of discussicnsamongst the members of the Meres and MiresResearch Groups, then alnc-qt exclusively biolcgists"The basic objectives were fai-rly selfish ones - moreguidance, more knowledge and more contact" But in theprocess ve have set a pattern vhich will surely be ofsome value to the Natural Environment Research Councilin its aim to cc-ord rnate the ef-f orts of envircnmentalscientists on a nation-wide basis. The -ti-eld workersin the Nature Conservancy have always had a strong sayi-n the way the Ccnservancy vorks" !/e think that thisis the way thi-ngs ought tc be - that we scientists mustnot sit back and expect the Research Council to promotethis kind of co-ordination for us: it must come from thepractical men themselves" The Natural EnvircnmentResearch Council has a tremendous amount cf vork to doto integrate the vork oi its own component bodi-es" Italso has the very bi-g job of developing its links wrththe universiti-es, Now I think we have here made a veryvaluable contributj-on by showing how this can be done inthe case of people actually doing research"I'One special characteristi-c o-f this meeting j-s that ithas had a very clear objective right from the start. Whenwe fi-rst discussed the possibility o-€ holding it, we envisagedit as a meeting to obtain information on subjects whichwere unfamilj-ar tc the ma;cri-ty o-f members of the twoResearch Groups, but only to obtain informaticn whj-ch wasdirectly relevant tc thei-r work. Later, I was criticizedfcr not accepting a whole 1ot o-t suggesticns whi-ch wereput to us of people whc were knorrn to be very good oncertaj-n aspects but rvere not wcrking in fj-elds directlyrelevant tc this ccn-telence. tnre thought o-f the titleso-t the papers befcre deciding on the pecple whom we wouldask tc speak.ItI shouid like to pay tribute to the many people whohave helped to find, or agreed to act ds, 'expertst forvaricus parts of the progranme and partj-cularly to CharlesSinker, vho has most willingly acted as our chr-ef consultantand adviser thrcughout the planning of the crn-terence.The burden of coruespondence and detailed arrangements havefallen very heavily on the shoulders o-t Philip Oswald, whohas borne it cheer-fully cn tcp of other practicatly fu11-time duties i-n the Conservancyf s Education Advisory Section;x/ithcut hj-m and the rest of my staff here this con-ferencewould not have qot off the qrcund"42

There seem to me to be fcur main grcups o-fproblems which we shoul-d be lcoking at as a follcwupto thi-q meeti-ng.1ft is clear that al-l of ycu uratlt tc maintainthe intercommuncaticn urhich has been the mainfeature o-f thi-s ccn-ference. I am Particularlynleaced to hear nc',-lD]p aSk -fOr mOfe fi-e]d meetinrrqlror-ause these Vi-}1 be far more Va]uablethan

4. to cJnsrder the preprraticn of a moncgraphon the uretiancl sites of the Ncrth-t^:'estMidlands; and,. tc prcduce prtceeCings cf this c,:n.Ference.tl14

Listo-f referencesAckers, P., & Harrison, A. J" M" (tg6g).Critical@ch Paper No" 5)Anon. (1965). Survey o-f hydrological activityin Treland. fnt. Assoc" Scle4t" Hydn8u11" , l!, 127--Baden, Wo, & Eggelsmann, R" (lS5+) "Der Wasserkreislauf eines NordwestdeutschmHochmoores " Hamburg, \rlasser & Boden.Baines , E. ( t 8:6 ) .PalatineThe hi-story o-f the CountyBennett, F" S" (t88+). The geology of the countryaround Attieborough,l'latton s4d lalymondham.Mem" geg1, Surv" U"K" (pp. 17-21)Boelter, D" H. (t065). Hydraulic conductivityof peats. Soil Sci", 1OO, 227-231.British Standards Institution (1564)" Methodsof measurement o.f liquid flov in opefr-ffiels"Parts 24 and 3. 2nd re-f " : Part 4 " )Cantor, L.M., & Moore, J.S. (tO5:)" The medj-eva1parks o-F the Elarls o-t Stafford at Madeley"N. Sta{fs" J. F}d Stud", 3, 37-58.Chitty, L. F" (lgzl ) " Dug-out canoes -tromShropshire, Trans" Shrops" archaeol. nat"Hist" Sos-, 4tClayton, c. c., & Smith, D"B" (tg6:)" Radioisotopes1n hvdrology" Vienna, Internationatl,-t.ffirc--Frn or" rrrr ..r A rt an 3ncy. r.rrConway, V. M., & Mi11ar, A" (tggO)" The hydrologyof some smal1 peat-covered catchments in theNorthern Pennines. J. fnstn'tr/at" Engrs, 14,415-424.4tr, 'a)

Crump, E. S. (lg>z). A new method of gaugingstream flow with li-ttle afflux by means ofa submerged weir o-f triangular profile.Proc" Tnstn civ. Engrs, 1, 223-242; 749-767 "Damman, A" V/" H. ?gAZ). Developnent o-f hydromorphichumus podzols and so.ne notes on theclassi-€icati-on of podzols in general"J. Soil Scj-", 13, 92-97"Dimbleby, G" !/" (lgAZ) " The developnent ofBritish heathlands and thei-r soils. Oxf . For.M%, ilo, 23. --Evans, W. B., tr/i1son, A" A", Taylor, B. J", &Price, D. (in press). The geology of thecountry betureen Macclesfield and Crewe.Mem. geol" Surv. U"K.Forsgate, J.(t s65) "hydrauli-c43-52 "A", Hosegood, P. H., & McCulloch, J"S.G"Design and j-nstallation of semi-enclosedlysimeters. Ag'ric, Meteorol", 2,Garbett, S. ( t Bt a 1 " Higlery o-t Wern and adjacenttownships" wem. lpGardner, A" L., Hunt, I" V., & Mitche11,(lgS+)" Tire "Muir-tadt' technigue ofimplovement J" Br" Grassld Soc",I" W"peatland9, 161-171.Godrvin, H" (tg:A), The h:'-story of the British.flora.Cambridge, UniversGorham, E, (tg>l). The chemical composition ofsome vaters from lowland lakes i-n Shropshire,England. Tellus,9, 174-179" (p" t-TT)Gough, R, (1815)" Memoj-rs of the parish of lv1vddle.Shreursbury. ( pp.-Hardy, E. rq. ( r g:g ) " Studi-es of the Post-qlacialhistorr,-)r of British vegetation" V" The Shrooshireand Fli-nt Maelor mosses.38, 364-396" (pp. 370-372 andHearne, r" , ed" (tlZo) "the ant iGGry. 3rdV:nn+ qrrBtrThe itineraryeo-0 John Letand

Hill Farming Research Organisation (lg6+).Third, reJorf , _L161-64, 7j-TB" (ttementr-tled Hydrolooy and Nutrient Balanceo-F Peat Cffidr" s. paterson)Hill, M" (t gf :)" The trr/eat-dmoors , 1560-1660"Trans " shtgp: :_ elgbaggf " nat " Hist " Soc " ,King, K. Y", Tannerj C" B,, & Suomi, V" E"\1956)" A floating 1ysimeter and itsevaporation recorder" Trans. Am. geophys" Un.37, 738-742"Manley, c. ltlfO)" Late-glacia1 climate ofNort!-t^rgs1 llngland" -Lpool "Manchr. geol. .To,?, 156-215" (p"2O7 )Mcllroy, I. C", & Sumner, C" J. (fgef). A sensitivehigh capacity bal_ance for continuousautomatic weighinE in-the fietd" J" agric"Enggg _&e!_., 6, 252-258.Meyboom, p" (1963). patterns o-fiir the -',rairie profite. fn:the Hydrolosy Symposium no" 3.FffiarE-Tofidf 6ffian?8.-='groundwater -f1owProceedinqs o-t5-33. --Tatf onarNash, J. E. (tggO). A r..yrrt hydrograph study, withparticuiar reference to Britistr catcfrments.Proc-. fnstn civ. Engqs, 17, 259"Page, -1,/. , Sg, (t gOg) " .\ri_cpl1_e__qounty Historyof ShrbF:hire* Vot--ffiPemin, R. M" S., Willis, E. I{", & Hodge, C" A" H.(tS6+). Dati-ng o-t humus pod.zols 6y residuarradiocarbon acti.vity"+ Nature, Lor-d"_, 2O2;165-166"Ramman, E" (tgtt)" Bodenkunde" BerIin, Springer"Reeve, R" C., & Kirkham, D. (lgSl)" Soil aniso_tropy and some field methods -for measuringpermeability" Trans.582-590.@, 3L,47

Singer, J" ?ge+)" The square-edged broad.-crested weir as a flow rneasuring device"itat . & Wat. Engng , 68 , 229-239 "Sinker, c" A. Ugez)" The North Shropshiremeres and moi.:es: a background -tor ecologists.Field Studies, 1 (+), 101-138"(pp" 106,-6 anffiTS1ack, tJ. j,, gL Ug>t). The Lordshj-,E ofosweslriz, T3-93-160T . sffiz )stapledon, R" c.. (1935)".. The land: now andto-morrow" London, naffi'fa:mnr.-o.--(t gf O) " Northern coniferous forestsoils: a popula'-oF-The wrr]-cn oetermt-ne -!-oFesT the productl_ve characterans. .-re-@erpress.Tanslsy, 'A,. G" (t g:g), The British IslanG and_lhetf_Vqgetation" ffi5Tfi@ress,--,**d.TFp.-254-ATry4JTodd, D" r. ( t g5g) " cr,gNew York, London, triTey"Toulmin Srnith, L" , ed. ( t gOZ-t o).of John L,e1end.-London.The itinerarv#Van Heuveln, F., Jongerius, .A", & Pons, L. J. (1950).Soil formation in orqanic soils" Trans" 7t!linf^.rtmnrJ-rILo UL,,IIIJI o uv]rQnil Qni"o\--Lo. 4, 195-204Volarovich, M" P. , Churaev, iV, V", & Minkov; 8.. ya-(lgSl)" In.,'estigation of the aqueous propertiesof peat by means o€ r.adioactive isotopes". .-Co1_r-old J",, \i.Iash., 12, 171-177 "Wedd,.-C"-8", & King, W. B. R" (l9z+). The geologyof the country around Flint, Hawarden and caei-gwrte.Mem" geo-l " Surv" U" K. ( p" 151)Yapp, W" B" (tg'z) " Leland's tfirrest"'Soc. Br. fs1., !,4o7-+a9"Proc" bot,48

A note on the -thernoveffiposgible use of fluorescentdyes for tracing(not presented at the conference)r. t,." SmrtnA fluorometer can be u-sed to detect minute concentratj.ons(dorint to fractions of a part per Amerj-can billion, i"e. 1Ov)o-t fluorescent dve i-n water" Dye techniques are by no meansnew, but -fluorometry has two distinct advantages. Thequantity of dye that must be used is small and easi-1y handledand there is no obvious colouration. A fluorometer is anoptical bridge, analogous to a ldheatstone bridge as used forthe determination of an unknowr resistance" Dye concentrationof particular samples can be determined in the laboratorybut, if a small generator is available, continuous monitoringin the field i-s possible"Tt would appear, therefore, that -fluorometry provides analternative to radioactive techniques -for tracing water movement,but without the health hazards and public relationsdifficulties. As far as is known, the method has never beenused in the United Klngdom for this type o-t work" TheWater Research Associ-ation has tried the use of a fluorometer-for dilution gauging, and there seems to be no reason vhy itshould not be successful for tracing the mc.rement of water.A Bri-tlsh-made f1-uorometer, -tor laboratory use on1y,costs about f.25O, while a portable American model, adapted forCOnti-nUOUS 1gr-nr-rii rnrr r'.rcf S neaf ly €800"49