Department of Botany, Faculty of Science, University of Peradeniya, Peradeniya, Sri Lanka. P. M. S. Ashton 5

Transcription

1 ECOLOGY OF TWO SELECTED LIANA SPECIES OF UTILITY VALUE IN A LOWLAND RAIN FOREST OF SRI LANKA : IMPLICATIONS FOR MANAGEMENT H. S. Kthrirchchi, K. U. Tennkoon, C. V. S. Guntilleke, I. A. U. N. Guntilleke Deprtment of Botny, Fculty of Science, University of Perdeniy, Perdeniy, Sri Lnk P. M. S. Ashton School of Forestry nd Environmentl Studies, Yle University, New Hven, CT 0, USA Author for corresponding: K. U. Tennkoon Emil : kushnt@pdn.c.lk

2 0 ABSTRACT Clmus ovoideus Thw. nd Coscinium fenestrtum Coler. re economiclly importnt, nturlly growing lin species in the distured hitts of lowlnd rinforests in Sri Lnk. Hrvesting their mture stems hs jeoprdized their survivl nd led to dwindling popultions. Growth performnce nd popultion sizes of these species nd their ecophysiology were exmined under three different cnopy removl tretments nd closed cnopy control of Pinus crie uffer zone plnttion of the Sinhrj forest. These tretments were in gps where three pine rows nd one pine row were removed nd under three pine rows with gps on either side. The initil light intensities of tretments nd control were,, nd mol m - dy - respectively. Popultion studies of Clmus spp. nd C. fenestrtum reveled tht they survive nd regenerte nturlly in the distured hitts compred to the undistured forest. After nine yers, oth lin species grew poorly in the Pinus understorey (control) compred to those of the tretments. During the study period, height increment of C. ovoideus ws est in the three-row cnopy removl tretment. In contrst to C. ovoideus, the ecophysiologicl fetures of C. fenestrtum vried little mong the cnopy removl tretments, suggesting tht they tolerte wider rnge of light levels. The study reveled tht oth species cn e successfully introduced to the Pinus crie uffer zones, degrded res of lowlnd rin forests in Sri Lnk, in order to conserve them in the wild, nd mnged them sustinly. KEY WORDS : Clmus, cnopy removl tretments, Coscinium fenestrtum, distured forest, Pinus enrichment tril, Sinhrj MAB reserve

3 0. INTRODUCTION The rin forests of Sri Lnk re of considerle interest in the historicl iogeogrphy of south nd south-est Asi (Guntilleke & Ashton ). Sri Lnk lso hs welth of economiclly importnt timer nd non-timer forest species. Much of the originl forests in Sri Lnk hve een clered for settlement, cultivtion nd production of timer. Out of this, only out eight per cent of lowlnd rin forests re now remining in the islnd. These forests recognized s floristiclly one of the richest terrestril iomes in south Asi re frgmented, degrded nd isolted throughout the lowlnd wet zone in Sri Lnk (Guntilleke et l. ). The remining government lnd tht orders these forests cn e descried s ndoned griculturl lnds tht were formerly forested nd tht hve now reverted to firemintined scrulnds or degrded lnds. Therefore, restortion of these degrded lowlnd rin forests is n immedite necessity. Some rurl communities in Sri Lnk hve trdition in conservtion prcticed in hrmony with nd prtil dependence on the nturl forests. Thus, it provides n excellent setting to exmine how these tropicl rin forests cn e mnged for multiple uses, following system tht is socilly cceptle, ecologiclly sustinle nd economiclly vile (Guntilleke, Guntilleke nd Aeygunwrden ). In the pst, nturl forests were lrgely used for the extrction of timer. Little ttention ws then pid to other useful resources, lrgely non-timer, tht were trditionlly eing extrcted nd used y the peripherl communities round forests. Therefore, it is impertive to understnd the ecology of rin forest species, which hve utility vlue other thn the timer, so tht they could e sustinly, mnged for non-timer forest products on scientific criteri. The need to select species tht will e protected, plnted nd encourged hs een emphsized in ll the studies on regenertion nd restortion. Hence it is essentil to understnd the ecologicl, iologicl, physiologicl nd silviculturl requirements in ll the developmentl stges of these species.

4 0 The lck of understnding of the requirements of individul species hs een considered s the gretest gp in our knowledge (Gómez-Pomp & Burley ). Clmus ovoideus Thw. nd Coscinium fenestrtum Coler. re nturlly growing economiclly importnt lin species round the distured sites of Sinhrj Mn nd Biosphere (MAB) reserve, Sri Lnk. Coscinium fenestrtum (fmily Menispermcee) is wide spred dioecious woody climer nturlly growing in the lowlnd wet zone of Sri Lnk. It is loclly known s Weniwlget nd grows in forest edges, gps nd distured hitts. The woody stem of this well-known medicinl lin contins the ctive compounds of ererine, jtrorhizine nd plmtine nd hs ntiiotic properties (Jyweer ). It is extensively used in indigenous medicine s itter tonic for the tretment of fever nd tetnus (Senerth 0). The stems of C. fenestrtum re used for cordge s sustitute for rope y the villgers. Most popultions of this species hs een exploited on sustntil scle in its nturl hitts nd it hs not een cultivted so fr. Clmus ovoideus (fmily Areccee; su fmily - Clmoidee), thorny lin loclly known s Tud Ren or Sudu Wewel, is n endemic cne species growing nturlly in the wet zone of Sri Lnk (de Zoys & Vivekndn ). The stems of this lin hve ecome n incresingly populr rw mteril for rurl industries. It is used to mke furniture, skets, ornments, house nd kitchen utensils nd lso s inding mteril. Most of these rttns re collected from the nturl forests nd cultivtion is very scrce. According to the Sri Lnk Forestry Sector Mster Pln (), except for two rttn species (C. rotng nd C. thwitesii), the rttn resources re certinly gretly depleted nd now confined lmost exclusively to protected res in the lowlnd rin forests of Sri Lnk. However, de Zoys & Vivekndn () reported tht due to the illicit hrvesting of good qulity, lrge dimeter rttn (C. ovoideus) tht is preferred y the industry, is on the verge of ner exhustion in Sri Lnk.

5 This pper presents informtion on the ecologicl nd silviculturl strtegies of the lin species, Coscinium fenestrtum nd Clmus ovoideus which grows nturlly in the Sinhrj rin forest of Sri Lnk. In our study we hope to clrify specificlly the following: i) Wht is the popultion size nd size clss distriution of individuls of ech of these species in forest tht hs een selectively logged in the pst nd is t present regenerting? ii) Do they perform differently in different prts of selectively logged forest nd in the undistured forest? iii) Do these two species respond differently to different size cnopy gps in Pinus uffer zone enrichment stnd? Do they show differences in their mortlity, growth rtes nd ecophysiology in different size gps? The nswers to these questions will throw light on the silviculturl strtegies tht cn e used to promote these two lin species in restortion trils of lowlnd rin forests of Sri Lnk.. MATERIALS AND METHODS 0. Study Sites The study ws crried out in nd round the Sinhrj Mn nd Biosphere (MAB) reserve ( ' N, 0 ' E) in south west of Sri Lnk. The totl conservtion re of Sinhrj comprises, h including out,000 h of primry forest, where over 0% of the tree species re endemic to the islnd (Gunntilleke & Gunntilleke ), secondry forests nd fernlnds. The rin forest djcent to the study res hs een descried s mixed-dipterocrp forest type nd elongs to the Mesu - Shore forest type (Guntilleke & Ashton ). The climte of this region is chrcterized s sesonl nd perhumid. Men monthly temperture rnges etween º C nd º C with n nnul rinfll of etween,00 mm nd,000 mm (Ashton ). The popultion studies of the study species were crried out in the prt of distured forest sites nd some selected res of the forest fringe where these species grow well. The

6 0 distured re of the reserve ws used for timer extrction for the supply of plywood etween. The study site for the investigtion of growth performnce of the two lin species in different size gps ws in the enrichment tril set up in prt of Pinus crie vr. hondurensis (Sénécl) Brr. et Golf. plnttion of the uffer zone ordering the northwestern prt of the Sinhrj MAB reserve. This enrichment tril, estlished in in the P. crie uffer zone plnttion (Gmge ) hd een plnted in nd protected for the lst twenty three yers Before estlishing the P. crie plnttion, this re ws originlly n ndoned griculturl lnd (Ashton et l. ). The verge slope of the study site is out 0, sloping towrds the north-south direction. The P. crie trees were plnted t spcing of m x m in rows ligned in the north-south direction s descried in Ashton et l. ).. Smpling for Popultion Density nd Size Distriution in the Distured Forest In prt of the selectively logged forest, permnent plots (nine for C. fenestrtum nd for Clmus) were estlished in 000 / 00 for popultion studies. Smpling sites were selected in different res of the forest where these two species were present. Within site, plots were rndomly demrcted nd the perimeter of ech plot ws mrked y pinting ring round the stem of the order trees using wter resistnt yellow pint. In these plots ll the enumerted individuls of the study species were permnently tgged using Aluminum numer tgs. For C. fenestrtum, smpling ws crried out in three different sites in the distured forest nd in the forest fringe due to scrcity of this species in other res. The site in the forest fringe ws closer to villge in the perimeter of the reserve. For Clmus species, five different sites were smpled. For ech species three trnsects, ech 0 m x m, were smpled in ech site. Since well-grown cne lins hve smooth woody stem once the lef sheths t the se perished, it ws not possile to identify them to their respective

7 0 species. The rrngement of spines on the lef sheth enles their identifiction. The pex of the plnts ws high ove the ground (> 0 m) nd s stems of the different species were intermingled it ws difficult to discern the identity of the individuls. The Clmus enumerted for popultion studies therefore elong to three species, viz., Clmus ovoideus, Clmus zeylnicus Becc. & Hook. f. nd Clmus thwitesii Becc. & Hook. f. Ech individul ws tgged t the root collr for future monitoring. For the cne species, the root collr dimeter, shoot dimeter ( m ove the root collr) of ech of the stems in clump nd the numer of stems per individul clump were recorded. In the cse of C. fenestrtum, the root collr dimeter nd shoot dimeter ( m ove the root collr) were mesured for ech individul. Size vrition mong individuls of the study species sed on root collr dimeter nd shoot dimeter ws investigted. For oth species, the site vrition ws tested using GLM (Generl Liner Model) procedure of Sttisticl Anlysis System (SAS) version. (SAS Institute Inc. Cry, N. C.).. Ecophysiologicl Investigtions in the Pinus Enrichment Tril The Pinus enrichment tril, ws the study site for the ecophysiologicl investigtions of these two lin species. This enrichment tril hs een set up s split-plot design with two fctor fctoril comintion comprising three replictes (locks). The min fctor in the experiment is the different light tretments including the control, creted y removl of the Pinus trees in. The su fctor in the experiment is represented y the different study species (Gmge, ). Three replictes hve een estlished for ech light regime. The light tretments were otined y the removl of prt of the P. crie cnopy. In two of the tretments, three rows, nd one row of pines were removed leving distnce of three pine rows etween these two tretments (Fig. ). We lso considered the gp exist with three pine rows etween the two removl tretments s third light tretment for our study. The

8 0 control ws the light level eneth the closed cnopy of the Pinus crie without removing ny pine rows. This control ws locted wy from the cnopy removl tretments to void ny edge effects influencing the under plnted seedlings. In My, twenty individuls of ech study species, Clmus ovoideus & Coscinium fenestrtum were initilly plnted in the three rows removed, one row removed, three pine rows underplnting tretments (the pine rows etween the three nd one pine row removed tretment) nd in the control per lock. The dily photosynthetic photon flux (DPPF) received t ground level y the cnopy removl tretments nd the control initilly were s follows: three pine rows removed ( mol m - dy - ), one pine row removed ( mol m - dy - ), three pine rows under plnting ( mol m - dy - ) nd the closed cnopy, which served s the control ( mol m - dy - ). Growth performnce nd physiologicl ttriutes of C. fenestrtum & C. ovoideus plnts estlished under the three different light regimes creted y cnopy removl nd in the closed cnopy control were exmined. The growth mesurements of the study species hve een nnully recorded over nine yers (-00) since the inception of the enrichment tril. Their root collr dimeters (RCD) were recorded using vernier cliper nd dimeter tpes when they grew igger. Plnt heights of the surviving individuls were recorded only up to, due to the difficulty of mesuring the ccurte height of the grown-up plnts. Height ws mesured from the ground to the highest point of the plnt using surveying stff. Annul increments of RCD nd height were clculted from records mde etween to 00 nd to for ll the existing individuls respectively. Ded seedlings were counted nd recorded t ech smpling period. Since rndomly selected seedlings were tken for destructive smpling two yers fter estlishment of the tril (August, ), seedling mortlity ws clculted during the period to 00 for oth species.

9 The physiologicl mesurements (photosynthetic rtes nd stomtl conductnce) of the study species were recorded in Ferury 00. Gs exchnge mesurements were otined using closed system LiCor 00 portle infrred gs nlyzer (Li 00, Lincoln, Nersk) following the method descried in Ashton nd Berlyn (). From ech lock three representtive plnts per species per tretment nd the control were rndomly selected for these studies. In ech of these plnts single fully exposed, expnded, undmged, intct lef t out m ove the ground level ws selected for susequent physiologicl mesurements. All mesurements on these selected leves were mde under mient conditions (CO concentrtion of pproximtely 0 µmol mol -, reltive humidity 0- per cent nd when photon flux density ws etween 0 00 µmol m - s - ). For smpling, the one litre lef chmer without the rtificil light source ws used. The lef re of the chmer ws set s cm for the rod-lefed C. fenestrtum nd s cm for nrrow lefed C. ovoideus. The irflow rte ws mintined t 00 µmol m - s - nd the stomtl rtio ws kept t 0.. To void is from diurnl effects, smpling ws done etween.00 m to.00 pm on sunny dys s descried in Ashton nd Berlyn () nd Tennkoon et l. (). Ech gs exchnge mesurement took plce during 0-0 s enclosure of the leves of species, tking cre to void periods of rpidly chnging light conditions efore or during mesurements. The study species did not show the mid dy closure of stomt during the period gs exchnge mesurements were tken. The three replictes of ech species in ech 0 light tretment were smpled within one dy to void ny smpling errors. Ech replicte plnt ws sequentilly mesured, six times over this time period. Ech mesurement of lef comprised set of three sequentil redings. From these mesurements, the net photosynthetic rtes nd stomtl conductnce were determined. Dt on percentge mortlity, growth over nine yers, nnul growth increments etween - 00 nd lef physiologicl mesurements were nlyzed y nlysis of

10 vrince (ANOVA) procedure of the Sttisticl Anlysis System (SAS) version. (SAS Institute Inc. Cry, N. C.). Anlyses were tested for differences mong light tretments, species, lock effects nd interctions etween species nd tretments t % significnce level. Owing to some seedling mortlity nd missing vlues in growth prmeters of some individuls dt were sujected to unlnced ANOVA, using GLM (Generl Liner Model) procedure of SAS. The effect of different cnopy removl tretments on ech of species ws determined y one wy nlysis of vrince nd then multiple comprisons mong mens y the Duncn Multiple Rnge Test (DMRT) t P < 0.0 level using SAS procedures. All dt on percentge seedling mortlity were rcsine trnsformed prior to nlysis. Dt on growth over nine yers, growth increments nd physiologicl mesurements which were not normlly distriuted, were trnsformed to their logrithmic vlues. The trnsformed dt were used for nlyses; where pproprite mens of the rw dt were used to plot the grphs. 0. RESULTS. Popultion Studies in the Distured Forest A totl of individul clumps nd stems of Clmus spp. were found within the 0. h smpled in the distured sites (study plots in the selectively logged re) of the Sinhrj forest. The numer of individuls nd stems vried considerly mong the five sites. The highest numer of individuls () nd stems () were recorded within the site one (Tle ). Except t one site (site three), more thn fifty per cent of the individuls hd multiple stems. The numer of stems per clump rnged etween. Most individuls hd stems per clump. Men root collr dimeter (P = 0.0) nd men shoot dimeter (P = 0.0) of the Clmus stems vried significntly mong the five sites. In their root collr dimeter (RCD) distriution of the Clmus stems, size clss. cm hd over fifty per cent of the stems in ll the sites smpled (Fig. ). The proportion of

11 0 stems hving. cm RCD ws more thn twenty per cent nd only. per cent nd. per cent in the size clsses etween. cm nd. cm respectively (Fig. ). In C. fenestrtum, within the three different sites smpled in the distured forest, 0, nd individuls were recorded. For ll individuls smpled, the men root collr dimeter per individul ws.0 cm nd the men shoot dimeter per individul ws. cm. Among the three different sites, the men root collr dimeter of the individuls did not vry significntly (P = 0.) ut the men shoot dimeter ws significntly higher in sites one nd two compred to tht in site three (P= 0.00; see Tle ). The proportions of individuls of C. fenestrtum in different root collr dimeter clsses showed tht, site three hd higher proportion of smll individuls (%) in the RCD size clss. cm reltive to tht in site one nd site two. Between per cent of individuls in ech site hd RCD of. cm. However, those over cm RCD were present only in sites two nd three, where they represented % of ech of these popultions (Fig. ). In ech of the three sites, in contrst to RCD, the shoot dimeters in - per cent individuls rnged etween. cm, where s the proportions of individuls etween. cm ws less thn twenty one per cent (Fig. ).. Popultion Sizes of the Lin Species in the Selectively Logged nd n Undistured Forest In the h forest dynmic plot demrcted for the long term monitoring of the growth of species in n undistured re of the Sinhrj forest only individuls of the cne species nd none of the C. fenestrtum were recorded (C. V. S. Guntilleke & I. A. U. N. Guntilleke, unpulished dt). In the present study in contrst, we recorded s mny s individuls of Clmus spp. nd individuls of C. fenestrtum in just 0. h of the selectively logged forest. This supports the oservtions of the derth of these two lin species in the undistured forests compred to the distured sites in Sinhrj.

12 . Seedling Mortlity nd Growth Performnce in Different Size Cnopy Gps Results of seedling mortlity during to 00 filed to show ny significnt differences mong cnopy removl tretments. The percentge mortlity of oth study species in the closed cnopy control ws highest compred to results of the cnopy removl tretments (Fig. ). As depicted in figure, the comprisons showed tht, men root collr dimeter, men height nd their increments of C. fenestrtum fter nine yers were significntly higher in cnopy removl tretments compred to the closed cnopy control. The differences of C. fenestrtum mong tretments were not significnt except the nnul root collr dimeter increment which ws significntly higher in the three rows removed tretment compred to the other two cnopy removl tretments. The results showed tht, men height nd its increment per yer were significntly higher in cnopy removl tretments thn the control for C. ovoideus. The men nnul root collr dimeter increment of C. ovoideus ws higher in the closed cnopy control (where C. fenestrtum nd C. ovoideus plnts were estlished under intct Pinus plnttion) compred to the cnopy removl tretments (where the lins were estlished under one nd three pine rows removed res nd in strip where only three pine rows were left ehind). 0. Lef Physiologicl Investigtions The results suggest tht, ech of the species hd its est net photosynthetic rte under different cnopy removl tretments (Fig. ). The highest men net photosynthetic rte recorded for C. ovoideus ws in the one pine row removed tretment, nd for C. fenestrtum it ws in the three pine rows removed tretment nd lso in the control compred to the two remining cnopy removl tretments nd where relevnt to the control. Results of stomtl conductnce reflected different trends etween the species nd mong the cnopy removl

13 tretments. The stomtl conductnce ws significntly higher in the three pine rows removed tretment for the C. ovoideus nd in the one pine row removed tretment nd three rows underplnting tretments for C. fenestrtum compred to the other tretments nd control (Fig. ). 0. DISCUSSION Although commercil selective mechnized logging nd disturnces ssocited with it cused some extent of destruction to the forest, the present study crried out 0 yers fter logging, showed tht the study species could survive nd regenerte nturlly in the distured sites of the Sinhrj forest. Results of this study further showed tht regenertion of Clmus spp. in their nturl hitts could hve occurred either y seeds or vegettively y uds t the rooting points. Single stem individuls my hve possily risen from seeds dispersed y ts, polects nd other dispersers to sites fr wy from their mother plnts. Seeds of oth species hve pulp tht ttrcts dispersl gents. On the other hnd, individuls with multiple stems could hve risen from vegettive shoots rising t the rooting point, or from those plnts tht would hve remined in dormnt stte efore logging. The growth rtes of these multiple nd single stem cne plnts nd their reltionship with ge in these hitts should e monitored to test for their growth differences if ny. The more or less similr root collr dimeter distriutions shown y the individuls in different sites depict the low vriility mong sites. In contrst to cne, the nturl regenertion of Coscinium fenestrtum is known to e difficult due to the un-orthodox nture of the seeds, where the verge moisture content is well over % nd seeds cnnot withstnd desicction. Studies hve further shown tht, seeds of C. fenestrtum re extremely sensitive to low humidity levels (Bndr et l. 00).

14 0 The performnce of C. fenestrtum vried mong the three different sites smpled. Sites one nd two were locted within the forest reserve nd the site three ws locted in the forest fringe, ordering the reserve. All the growth mesurements mesured in the site three were lower compred to those of the two sites tht were within the forest. These differences etween site three nd other two sites could e ttriuted to the degree of disturnce in them due to removl of mture lins y villges living in the vicinity. These results further showed tht the men root collr dimeter of plnts growing in ll three nturl forest hitts ws greter thn the mximum root collr dimeter (. cm) recorded fter nine yers growth in the three pine rows removed tretment of the Pinus uffer zone enrichment tril. Studies crried out y Senerth (0) showed tht men density of the C. fenestrtum in the forest fringe t Sinhrj ws per m. However, the present study showed reduction in the density of the individuls in the forest edge, where the vlue ws nd individuls per m in site one nd site two respectively. According to study conducted yers efore the present investigtion (Senerth,0), higher proportion of the individuls smpled in the forest fringe of the Sinhrj forest hd shoot dimeter rnging etween. cm. In contrst, in the present study % of the individuls smpled were represented y shoot dimeter of. cm. This could e due to the growth of individuls over the lst ten yers. The different trends in most of the lef physiologicl ttriutes in oth species, mong the tretments nd control my e due to the comprtively similr light conditions (. -. mol m - dy - ) t m ove the ground, the height t which the leves were hrvested for physiologicl studies. The sptil nd temporl light vrition of the understorey is mjor fctor tht ffects the physiologicl processes of the two species investigted. The study lso demonstrtes the chnges etween the initil light intensities t the commencement of the experiment (in ) nd those t present (in 00) due to the growth of the introduced plnts nd how these chnges hve ffected the physiologicl responses of these plnts. The existing

15 0 verge totl dily photosynthetic photon flux (DPPF) m ove the ground level of the tretments investigted s prllel study in the rows removed, rows removed, three rows underplnting tretment nd the control were found to e.,.,. nd. mol m - dy - respectively. In the h forest dynmic plot demrcted for the long term monitoring of the growth of species in n undistured re of the Sinhrj forest only individuls of the cne species nd none of the C. fenestrtum were recorded (C. V. S. Guntilleke & I. A. U. N. Guntilleke, unpulished dt). This supports the oservtions of the derth of these two lin species in the undistured forests compred to the distured sites in Sinhrj. The results of this study provide importnt informtion on the survivl, growth nd physiologicl responses of two ntive lin species in n enrichment tril of the P. crie uffer zone plnttion. Previous studies (Gmge, ) hve shown tht three yer old seedlings of these species cn e estlished under suitle gp sizes of P. crie plnttions. The results of this study confirm the ility of nine-yer-old plnts of the two study species (C. fenestrtum nd C. ovoideus) to grow successfully under suitle size gps in the P. crie plnttion in the uffer zone of the Sinhrj MAB reserve. When one considers the two lin species, C. fenestrtum nd C. ovoideus, plnt height is good mesure of their growth s well s of the quntity ville for extrction ecuse in oth species the stem is hrvested for their utility vlue. The results demonstrte tht, even fter nine yers of growth, C. fenestrtum nd C. ovoideus grew poorly in the Pinus understorey thn in the other cnopy removl tretments, ut they showed different growth strtegies. The est height fter nine yers for C. ovoideus ws oserved in the three-row cnopy removl tretment, compred to ll the other tretments tested in this study. In contrst to cne, C. fenestrtum showed only smll vrition, mostly non-significnt, in terms of growth nd other ecophysiologicl fetures mong the cnopy removl tretments.

16 0 This depicts tht C. fenestrtum hs wider tolernce rnge where it grows etter under the light intensities present in the three pine rows removed, one pine row removed nd three pine rows under plnting tretments. Although not significnt, results showed tht, oth lin species hd poor percentge survivl under the lowest light tretment viz., closed cnopy control compred to ny of the Pinus cnopy removl tretments. The heights of oth species nd the root collr dimeter of C. fenestrtum incresed considerly with the increse initil light level from - mol m - dy -. Increses etween - mol m - dy - however, did not show much vrition in these growth prmeters. Therefore, sed on the results, oth lin species cn e grown economiclly nd successfully in Pinus stnds, where every forth row of pines is removed. In these pine stnds the lins could e grown in the gp center s well s in the understory of the tree pine row left ehind. This suggests tht - yers old plnts of C. ovoideus nd C. fenestrtum re shde intolernt. The root collr dimeter is not very successful growth mesurement for C. ovoideus ecuse the slower growing smller C. ovoideus plnts hve shething lef se round the root collr. In the well-grown C. ovoideus plnts the sheths wer wy nd exposes the smooth cne stem. Hence the ctul dimeter of the root collr of mture cne plnts ecome smller due to the wering off of the sheth. The ecologicl, physiologicl nd silviculturl findings of these ntive non-timer forest species should lso e exmined in the light of their sustinle extrction levels, yield nd production in this type of mnipulted mixed species plnttion. Continution of this investigtion should provide vlule informtion on some of the economicl spects of these species nd the production levels under these mnipulted conditions. The Ntionl forest policy () of Sri Lnk (Sri Lnk Forestry Sector Mster Pln, ), proposes the sustinle mngement of stte forests for multiple uses, through involvement of locl people who will prticipte in plnning, implementing nd enefiting

17 0 from nturl forest mngement. According to the recent forest clssifiction (Sri Lnk Forestry Sector Mster Pln, ), the clss III forests re minly to e used for multiple uses such s sustinle production of wood nd non-timer forest products for the enefit of the locl communities. This includes the uffer zones tht protect (strictly conserved or preserved forests for non-extrctive uses i.e. Clss I nd Clss II forests. The Clss IV forests comprise plnttions nd gro-forestry systems on stte lnds tht would e mnged for production of wood nd non-timer forest products. The Forestry Sector Mster Pln of Sri Lnk () proposed progrms on multiple use of forests tht cover ll these forest ctegories. Therefore, the results of the species investigted in the present study provide n insight to the est wys tht could e implemented when these species re introduced or cultivted in the mixed species plnttions of the uffer zones of lowlnd wet zone in Sri Lnk. It lso provide n insight in to the susequent mngement strtegies tht could e dpted in the low lnd wet zone forests tht re ssigned for production with the help of community prticiption. In ddition the findings of this study re invlule when drwing up the suitle silviculturl prctices for implementtion to enhnce the growth of these species in their nturl forest fringe hitts, or in degrded forests. The informtion on popultion sizes of Coscinium fenestrtum nd Clmus spp. could e useful in developing silviculturl systems for these study species tht re suitle for degrded nd selectively logged forest hitts in the low lnd wet zone of Sri Lnk. This study indicte much vrition in the densities of the two lin species nd in turn the vilility of these resources in different sites of the selectively logged forest nd the forest fringe. This informtion is impertive to drw up guide lines for their sustinle extrction from the wild. The continued monitoring of the permnent plots demrcted in this study over long period would further provide vlule informtion on their rte of growth, mortlity nd their regenertion strtegies within the nturl hitts.

18 . ACKNOWLEDGEMENTS Finncil ssistnce provided y the NAGAO Nturl Environment Foundtion nd NIES Jpn, Ntionl Science Foundtion, Sri Lnk nd McArthur Foundtion, USA re grtefully cknowledged. We thnk the Forest Deprtment of Sri Lnk for grnting permission to study in the Sinhrj Forest nd to use the fcilities t the field sttion.

19 0. REFERENCES Ashton, P.M.S. (), Some mesurements of the microclimte within Sri Lnkn tropicl rinforest, Agriculturl nd Forest Meterology, : -. Ashton, P.M.S. nd G. P. Berlyn. (), Lef dpttions of some Shore species to sun nd shde, New Phytologist, : -. Ashton, P.M.S., S. Gmge, I.A.U.N. Guntilleke nd C.V.S. Guntilleke.(), Restortion of Sri Lnkn rinforest: using Crien pine Pinus crie s nurse for estlishing lte successionl tree species, Journl of Applied Ecology, : -. Bndr, M, K. U. Tennkoon, C.V.S. Guntilleke. (00). Seed Biology of the Medicinl Linn Coscinium fenestrtum. Proceedings of the Forestry nd Environment Symposium : de Zoys, N. D. nd K. Vivekndn. (), The moo nd rttn cottge industry in Sri Lnk. Forest Deprtment nd IDRC, Colomo, Sri Lnk. Gmge, S. (), Fesiility studies on underplnting multiple use species in uffer zone pine plnttions of the Sinhrj MAB reserve, M. Phil. Thesis, University of Perdeniy, Sri Lnk. Gómez-Pomp, A. nd F.W. Burley. (), The mngement of nturl tropicl forests, in A. Gómez-Pomp, T.C. Whitmore nd M. Hdley (eds), Rin forest regenertion nd mngement, pp. -, Volume. UNESCO, Pris nd Prthenon pulishing group Ltd., UK. Guntilleke, C.V.S. nd P.S. Ashton. (), New light on plnt geogrphy of Ceylon, II. The ecologicl iogrphy of lowlnd endemic tree flor, Journl of Biogeogrphy, : - 0. Guntilleke, C.V.S., I.A.U.N Guntilleke nd P. Aeygunwrden. (), An interdisciplinry reserch inititive towrds sustinle mngement of forest resources in lowlnds rin forest of Sri Lnk, Journl of Sustinle Forestry, : -.

20 Guntilleke, I.A.U.N. nd C.V.S. Guntilleke. (), Sinhrj: World Heritge Site. Ntionl Science foundtion, Sri Lnk. Guntilleke, I.A.U.N., P.M.S. Ashton, C.V.S. Guntilleke nd P.S. Ashton. (), An over view of seed nd seedling ecology of Shore (section Doon) Dipterocrpcee, in I.M. Turner, C.H. Dlong, S.S.L. Lim nd P.K.L. Ng (eds), Biodiversity nd the Dynmics of Ecology, pp. -. DIWPA series. Jyweer, D.M.A. (), Medicinl plnts used in Ceylon, Prt IV, Ntionl Science council of Sri Lnk, Colomo, Sri Lnk. Senerth, D.M.B.D. (0), Biologicl Studies on Coscinium fenestrtum Coler. (Menispermcee), M. Phil. thesis. University of Perdeniy, Sri Lnk. Sri Lnk Forestry Sector Mster Pln. (), Forestry plnning unit, Ministry of griculture, lnd nd forestry, Colomo. Tennkoon K.U. J.S. Pte, D. Arthur. Ecophysiologicl spects of the woody root hemiprsite Sntlum cumintum (R.Br.) A. DC. nd its common hosts in south Western Austrli. Annls of Botny 0 (), -.

21 Tle. Totl numer of individuls, stems, numer of individuls with multiple stems, men root collr dimeter (RCD) nd men shoot dimeter (SD) per stem of Clmus spp. smpled in five different sites of the distured forest in Sinhrj MAB reserve, Sri Lnk. Percentge of stems hving multiple stems is given in prentheses. Letters qulittively indicte (<<c) the significnt differences mong the sites t P< 0.0. Site Site Site Site Site Sites - Totl no.of individuls/0. h 0 Totl no. of stems / 0. h No. nd (%) of individuls with multiple stems () () () 0 () () () Men RCD/stem (cm) Men SD/stem (cm)

22 Tle. Totl numer of individuls, men root collr dimeter (RCD), men shoot dimeter (SD) per individul of Coscinium fenestrtum in the three different sites of the distured forest in Sinhrj MAB reserve, Sri Lnk. Letters qulittively indicte (<<c) the significnt differences mong the sites t P< 0.0 Mesurements Recorded Site Site Site No. of individuls / 0. h 0 Men RCD (cm) / individul.0.. Men SD (cm) / individul...

23 Scle : m pine rows removed ( mol m - dy - ) pine rows under plnting ( mol m - dy - ) pine row removed ( mol m - dy - ) (Not Shown) Closed understorey (control) ( mol m - dy - ) Figure. Stnd profile of the cnopy removl tretments nd control (not shown here) of one lock of the Pinus enrichment tril in the uffer zone of Sinhrj MAB reserve, with their respective light intensities (within prenthesis) t the ground level in, when the tril ws set up.

24 -. cm -. cm -. cm -. cm -. cm 0 0 Numer of stems / 0. h Site Site Site Site Site Figure. Root collr dimeter distriution of Clmus spp. in five different sites of the distured forest in Sinhrj MAB reserve, Sri Lnk.

25 -. cm cm -. cm > cm 0 0 Root collr dimeter % of individuls Shoot dimeter Site Site Site Figure. Root collr dimeter nd shoot dimeter distriutions of Coscinium fenestrtum in three sites (sites, nd where n= 0, nd respectively) in prt of the selectively logged nd regenerting forest in the Sinhrj MAB reserve, Sri Lnk. Vlues ove rs indicte the proportions of individuls in ech size clss in ech site.

26 0 C. fenestrtum C. ovoideus % Seedling mortlity R R U CU Cnopy removl tretments R R U CU Figure. Men percentge mortlity of C. fenestrtum nd C. ovoideus from - 00 when grown under different cnopy removl tretments (R- rows removed, R - one row removed, U - rows under plnting nd CU - closed cnopy control) in the Pinus enrichment tril of the uffer zone of Sinhrj MAB reserve, Sri Lnk. Brs indicte the stndrd error of the men. Vlues ove show the men percentge mortlity of ech species under ech tretment.

27 Men RCD (cm) Men height increment Men RCD increment (cm) / yer (cm) / yer Men height (m) C. ovoideus C. fenestrtum c c R R U CU R R U CU Cnopy removl trerments Figure. Men root collr dimeter (RCD), men height nd their increments per individul per yer of C. ovoideus nd C. fenestrtum fter nine yers growth under different cnopy removl tretments (R - rows removed, R - one row removed, U - rows under plnting nd CU - closed cnopy control) in the Pinus enrichment tril in the uffer zone of Sinhrj MAB reserve, Sri Lnk. Brs indicte the stndrd error of the men. Letters qulittively indicte significnt differences (>>c) mong tretments for ech species ccording to Duncn's multiple rnge test (P<0.0).

28 Net photosynthetic rte (µmol CO m - s - ) C. ovoideus C. fenestrtum Stomtl conductnce (mol H O m - s - ) R R U CU R R U CU Cnopy removl trerments Figure. Net photosynthetic rte nd stomtl conductnce of C. ovoideusnd nd C. fenestrtum under different cnopy removl tretments (R - rows removed, row removed, R - rows removed, R - rows removed, U - rows under plnting nd CU - closed cnopy control) in the Pinus enrichment tril in the uffer zone of Sinhrj MAB reserve, Sri Lnk. Brs indicte the stndrd error of the men. Letters qulittively indicte significnt differences (>>c) mong tretments for ech species ccording to Duncn's multiple rnge test (P<0.0).