NATURAL REGENeRATION IN KEKILLA FERNLANDS IN THE PERIPHERY OF SINHARAJA WORLD HERITAGE SITE

In tropical moist climate Dicranopteris !inearis (Kekilla) fernland can develop as a resultof rain forest clearance followed by frequent burning. In Sri Lanka D. linearis fernlandsare capable of suppressing the natural regeneration of rain forest. Sinha raja WorldHeritage Site is one of the least disturbed and biologically unique lowland rain forest nowremaining in Sri Lanka. Some areas of the periphery of Sinharaja are covered with Dlenearis fern. Natural regeneration dynamics of soil seed banks need to be studied as apossible source of regeneration for forest restoration in these fern lands.This study was carried out to understand the natural regeneration of soil seed bank inKekilla fernland with reference to surface soil disturbance and trophographic levels in theperiphery of Sinharaja World Heritage Site.Three sites of Kekilla fernlands were selected for the study. Two surface soil disturbancetreatments were applied to each site. The first treatment (Root Removal) was applied at thebeginning of the study. The next treatment (Till) was applied to each site after six monthsfrom the first treatment. Seeds in the soil were allowed to germinate and seedlings werecounted once in two weeks during the first four months. After four months the seedlingswere recorded once a month. Transectswere laid out in each site to understand the floristiccomposition in surrounding vegetation of D. lenearis fernlands.Seedlings of 35 taxa were identified during the period of study. The study revealed thatboth soil disturbance treatments can facilitate the establishment of herbs, shrubs and treesin the fern land dominated by D. lenearis. Results showed that herbs, shrubs, grassesrepresented the greater proportions of seedling recruitment than pioneer trees. Seedlings ofprimary forest species were not existentSpecies composition of soil seed bank ill three-tophographic positions was not significantlydifferent. Numbers of species and seedling density were greatest in root removal treatment.Seedlings of primary forest species found in surrounding vegetation were not regeneratingin the plots studied. Only few pioneer tree seedlings were found in the plots, representingsurrounding vegetation of Kekilla fernland.

THE ECOLOGY OF Dipterocarpus zeylanicus PLANTATION AT INGIRIYA, SRI LANKA

The plantation forestry in Sri Lanka began in the late 19'h century. The forest coverprevailed at that time did not warrant a rapid expansion of plantations. Later, thedepletion of the forest resources compelled the Forest Department to embark onestablishing plantations. A rapid increase in plantation development was noted during the211d half of the 20'h century. The species selected for plantation establishment were mostlyexotics with few indigenous tree species.Holmes as a silviculturist in the Forest Department initiated the studies on the growthperformance of indigenous tree species. The present Dipterocarpus zeylanicus plantational Ingiriya was one such location established by him in 1940. At present there are otherindigenous tree species also growing in association with D. zeylanicus.A systematic sampling design was adopted for the study. The total sample area was 1.9375ha. The diameter at breast height and height of all the trees above 10 em were recorded in25mx25m plots numbering thirty-one. Seedlings and saplings in 2mx2m and 5mx5m plotswere also recorded. The number of plots in each case was 124. Important value indices forspecies. genera and families were calculated. Rank abundance curves were plotted.Endemic species in this plantation were recorded. Mean dbh, mean height, mean basalarea. and mean top height for D. zcylanicns were calculated. The diameter classdistribution of D. zcylanicus was plotted. Regression analysis was performed to observewhether any correlation exists between the dbh of D. zeylanicus against basal area of thesame and other species.The plantation recorded 82 species. 70 genera and 37 families. Among the 916 individualstems recorded :'i2(71) was D. zeylanicus. There were 248 individuals of D. zeylanicus perha.The paper highlights the lloristic. status of principal species, stand parameters and suggestinterventions for plantation management

A study on phytosociology of three isolated natural forest patches in Gampaha district

The study examined the phytosocioloy of selected three isolated natural forest patches in Gampha district viz. Horagolla National Park, Maimbulkanda Sanctuary and Yakadawala Man and Biosphere Forest Reserve. Plants equal or greater than 5 cm diameter at breast height, were sampled in 10 plots in each forest (plot size 5 x 100 m), plant less than 5 cm diameter at breast height and higher than 1.4 m height were sampled in 30 plots in each forest (plot size 5 x 5 m), and plants less than 1.4 m height were sampled in 120 plots in each forest (plot size 1 x 1 m). Ecological indices and important value index, which is expression of the dominance of particular species in different forest patch, were calculated.Total of 3308, 1324 and 3275 individuals were enumerated in Horagolla National Park, Maimbulkanda Sanctuary and Yakadawala Man and Biosphere Forest Reserves respectively. These individuals belong to 65, 100 and 100 species respectively. Their endemic percentages were 32.7%, 24.0% and 36.0% respectively. Total plant species recorded in all three forest patches were 144. Thirty eight (38) were found in all three forests. Sixty one (61) species were found only one of these three forests.Result of this study showed that difference in diversity is significant (p<0.05 all three comparison). But within 5 x 100 m plots and 5 x 5 m plots Maimbulkanda Sanctuary and Yakadawala Forest Reserves have not shown significant differences in diversity. However, these two forests have significant diversity differences with Horagolla National Park.Within 1 x 1 m plots Horagolla National Park and Yakadawala Forest Reserve have not shown significant differences in diversity. However, these two forests have significant diversity differences with Maimbulkanda Sanctuary.This study found that Artocarpus hirsuta – an introduced tree species rapidly spreading showing invasive characteristics in Horagolla National Park and started to spread nearby forests as well. This study also recorded natural populations of Cola accuminata first time in Sri Lank

Study of Topographic Variation in Leaf Traits of Selected Canopy and Sub Canopy Tree species in the Sinharaja Tropical Rain Forest

Sinharaja tropical rainforest is one of the most important ecosystems in the country and records a high number of endemic plant species. The objective of the study was to identify the variations in leaf morphological characteristics of canopy and sub canopy trees with the changes in topography. For the study six endemic species were selected with three species each representing the canopy and sub canopy groups. The leaves of fully matured trees were studied from two topographic positions representing the ridge and valley. Morphological characteristics compared include both measured parameters (leaf length, width, leaf area, fresh weight and dry weight) and derived parameters (moisture content, specific leaf area (SLA) and leaf dry matter content (LDMC)). When the cumulative mean values of the leaves for the two topographic locations are compared, the valley has higher leaf length, width, area, fresh weight, dry weight and SLA values. The LDMC and moisture content mean values are comparatively similar in both ridge and valley. However when individual species are compared between the two locations, some show the opposite trend to that of the mean values. Among the canopy trees, Anisophyllea cinnamomoides shows a significant difference (p<0.05) between ridge and valley in all parameters except SLA. It also shows the highest LDMC percentage among all six species at 56.72 percent in the ridge. Bhesa ceylanica shows a significant variation in all traits barring SLA and leaf length. B. ceylanica also has the highest mean values for length, width, area, fresh weight and dry weight among the six species. Palaquium petiolare shows significant variation between in only three parameters which are length, moisture content and LDMC. The three sub canopy species show lower differences in traits between the two locations. Among them Cullenia ceylanica shows a significant difference in both fresh and dry weight, moisture content and SLA. Garcinia echinocarpa shows a significant difference only among leaf length and SLA, with its ridge SLA mean of 5.6 mm2mg-1, being highest among all 6 species. Chaeocarpus castanocarpus shows the most difference among sub-canopy species with only length and width not showing a significant differenc

SEED BANK DYNAMICS OF KEKILLA FERN LANDS AND ABANDONED CHENA UNDER PARTIAL SHADE AND FULL SUN CONDITIONS

Seed bank dynamics can be considered an important component of the regeneration ofindividual plant populations and communities. Soil seed bank dynamics in Kekillafernlands and abandoned chena need to be studied as possible sources of regeneration forforest restoration of degraded lands.This study was done to understand regeneration dynamics of soil seed banks with referenceto two light regimes in Kekil1a fernlands and abandoned chena in the periphery ofSinharaja World Heritage Site.Sinharaja World Heritage Site is one of the least disturbed and biologically unique lowlandrain forests now remaining in Sri Lanka. Today some areas of the periphery of Sinharajaare covered with secondary scrub and Kekilla (Dicranopteris linearis) fernlands. Threesites of Kekilla fernlands and three sites of abandoned chena were selected for the study.Four soil samples were purposively collected from four different locations in each site.These four samples were pooled and mixed in a polythene bag. Eight trays were preparedusing one mixture of soil from one site. Four trays from each site were placed underpartial shade (750J.! mol m-2 S-1 ) and others were placed under full sunlight (2000J.! mol m-2S-I). Seeds inside the soils were allowed to germinate. Newly germinated seeds wererecorded every fifth day. All germinated seeds that were able to be identified wereremoved and counted once a month.Seedlings of 45 taxa were identified during the period of study. Among the countedseedlings a larger proportion was recruited under the partial shade treatment than full suntreatment. Results indicate that the number of species germinated from abandoned chenawas greater than that of Kekilla femlands. Finding suggest that in all treatments onlypioneer species germinated. Climax species were not represented in any of the sites orlight treatments

A study on tree diversity in lowland, sub-montane and upper montane forest formations along the Hapugastenna nature trail in the Peak Wilderness sanctuary

Hapugastcnna nature trail is one of sixth access way to peak "Sri-pada" that running through PeakWilderness sanctuary. It starts at the middle way of southern boundary of the sanctuary betweenRathganga and Waleboda and runs North-Western direction.This study examined the tree diversity in different forest formations along the trail. Twelve plots(each 5 x 100 m) were laid in lowland (6), sub-montane (4) and upper montane (4) forest formations.respectively. Altitudinal range oflowland plots were below 1000 m, sub-montane plots were between1000 -1550 m and montane plots were above 1550 m. All tree species over 10 ern dbh were selectedfor the study. Important value index (IV!) and Shanon's diversity index were calculated. IVI wascalculated for each family, genera and species separately.Recorded number of total individuals was 592 belong to 90 species, 55 genera and 26 families. Itincludes 58 endemic species with 3 endemic genera (Loxococcus -1 sp., Shumaeheria - 1 sp.,Stemonoporus= 6 sp.). A total of 58 (250 individuals), 32 (174 individuals) and 29 (168 individuals) treespecies were identified from lowland, sub-montane and upper montane forest formations, respectively.Identified species distributed in 3 forest formations as follows, lowland 43, upper montane 13, submontaneII, lowland and sub-montane 8, lowland and upper montane 2, sub-montane and uppermontane 8, all three formations 5. There were 35 endemic tree species in lowland (60.3 %) ,22 (68.7%) in sub-montane and 17 (60.7 %) in upper montane forest formations.According to the [VI values, in the lowland forest formation Dipterocarpaceae was the dominant family,Myristica was the dominant genus and Myristica daetyloides was the dominant species. In the submontaneand montane forest formations Palaquium rubiginosum was the dominant speciesThe diversity index (Shannon's) was calculated for each plot and three different forest formations.These results were analyzed using analysis of variance. It showed that there were significant differencesbetween lowland - montane lowland - sub montane formations. Same result showed for evenness anddominance.

GROUND HERBACEOUS FLORA IN UNLOGGED SITES OF SINHARAJA WORLD HERITAGE SITE

The composition and distribution of herbaceous plants were investigated at SinharajaWorld Heritage site.Previously unlogged torest areas were selected for the present study. Several transects weremarked purposively in each site from valley to ridge to study the topographical variation ofherbaceous plant distribution. Circular plots. each 10 m" were demarcated on each transectto study the herbaceous flora. In addition. 200 m2 plots surrounding the 10m2 plot weremarked to enumerate the tree species in the area. The distance between two. 200 1112 plotswas 20 m.In each plot number of plant species was recorded, Voucher specimens were prepared foridentification of species found in plots as well as outside thc riots. Dominance diversitycurves and Shannon diversity indices were prepared for each transect.Ninety one species belonging to 40 families were recorded. Twenty nine of 9 I species areround outside plots. The estimation of individuals of herbaceous plants per hectare was21.790. Herhs and herbaceous climbers represented 38.47% of the total herbaceous flora.Fern and fern allies represented 45.67(1,: and grasses and sedges 15),4%. respectively.Species rich families were Zingibcraccac (6 spp.) and Ruhiaceac (5 spp.) Densitydominance families were Rubiaccuc (6.97%) Zingibcraceae (3.9%). Mysinaccac 0.6%),Polipodiaceae (17Y1c,). Dennestaediaccac (7.8%) Cyatheaceae 0.8%) and Cypcraaccae(5.5%). Diversity indices in valley and ridge were 0.2153 and 0.1754. respectively.Results indicate the localised distrihution of herbaceous species in understory vegetation oflowland rain forest. This may he due to the differences in micro habitats from valley toridge.

SEEDLING GROWTH PERFORMANCE OF FOUR Syzygium species IN THE SIMULATED LIGHT AND SOIL NUTRIENT ENVIRONMENTS OF A RAIN FOREST IN SRI LANKA

Seedlings of four species of Syzygium (S. firmum, S. makul, S. operculatum, S.rubicundutn) were investigated for differences in growth and survival after one and halfyears growth in a nursery experiment. All four species co-exist in the moist evergreen rainforest of South western Sri Lanka. S. firmum is a canopy tree on valleys to midslopes. S.rubicundum is considered a canopy tree of late-successional forest on hill mid slops. BothS. makul and S. operculatum arc sub canopy trees of late-successional forest alongstreamways of lower slopes and valleys.Seedlings of each species were grown within replicated light and soil nutrient treatmentsfound in the groundstorey forest environments. The light treatments exposed seedlings toi) full sun; ii) sunlight like that at the center of a 200 m2 forest opening. iii) sunlight likethat at the center of a 400 m2 canopy opening; iv) 50% shade of sunlight with qualitysimilar to the outside edge of a 400 m2 canopy opening on the shaded side; v) 20% ofsunlight with a quality similar to the inside edge of a 400 m2 canopy opening on theshaded side and vi) I% of sunlight with a quality and amount similar to the forestunderstorey. Within each light treatment seedlings were grown with additions ofphosphorus, potassium, magnesium, al\ three combined and a control with no additionalnutrients. At the end of one and half years seedlings were measured for net photosynthesis,height increment, leaf number and survival.Seedling survival for all species was low in the forest understorey treatment. Both survivaland seedling height were greatest in shelters simulating forest openings. Leaf productionwas highest in full sun and inside edge light treatments and all species had their greatestnet photosynthesis in the inside edge treatment. For nutrient treatments phosphoruspromoted greatest seedling growth in all species

DIVERSllY OF UNDERSTOREY VEGETATION IN THREE LOWLAND RAIN FORESTS IN SOUTHWEST OF SRI LANKA

The study examined the diversity and composition of understorey vegetation in SinharajaMan & Biosphere forest reserve, Kanneliya forest reserve, and Oliyagankele forestreserve. The understorey vegetation was sampled in 54, 27, and 27 plots in Sinharaja FR,Kanneliya FR, and Oliyagankele FR respectively each 5 m x 5 m. Ecological indices andimportant value index. which is the expression of the dominance of particular species indifferent habitats, were calculatedThe diversity index (Shannon's) calculated for understorey species found in each plotenumerated at Sinharaja FR, Kanneliya FR. and Oliyagankele FR showed that that thereis no significant difference in diversity among reserves except for slightly higherdiversity observed in Kanneliya forest reserve. A total of 68, 77, and 63 understoreyspecies were found from Sinharaja, Kanneliya, and Oliyagankele FR respectively. Therewere 40 endemic understorey species in Sinharaja FR and in Kanneliya each, and 36 inOliyagankele FR. There were ill, 17, and 14 understorey species found only fromSinharaja, Kanneliya and Oliyagankele FR respectively. The most common family inSinharaja FR and Oliyagankele FR was the Euphorbiaceac, and Fabaceae was inKanneliya FR. There were slight differences in species composition within each forestreserve from valley to ridge.Results of this study shows that although the difference in diversity is not significant,there are differences in the composition of the understorey as the elevation and meanannual rainfall decreases from Sinharaja FR to Oliyagankele FR. This study also foundthat that are higher percentage of endemic in the understorey of all three study sites.

GROVITH PERFORMANCE OF LARGE DIAMETER RATIAN (Calamus) PLANTED UNDER PINE PLANTATIONS AT SINHARAJA BUFFERZONE

Rattans can be considered as the most important non-timber forest product. Due to heavyexploitation from the wild, the resource is declining at an alarming rate. The present studyexamined the growth performance in terms of plant height, total lengths of stems,diameter, clump formation and number of live leaves and average growth rates of threelarge diameter rattan species, namely Calamus zeylanicus Becc., Calamus thwaitesiiBecc., and Calamus ovoideus Thw. ex Trim, planted under pine plantations in the bufferzone of Sinharaja, Sri Lanka. Four sites of rattan plantations in ages, 8, 9, 10 and 12 yearswere selected with each site consisting of five plots. Lengths of stems were estimated andstern diameter was measured without the sheath. Number of live leaves and stems in aclump were counted in each plant. Number of pine trees of each site was counted and soilanalysis was carried out to depict the site 9ualit'l.The highest stem lengths were recorded in the oldest site and the highest mean heightrecorded afer 12 years was 20 m. Results showed that the height increases with the ageand the average growth rate decreases. The highest avera~e growth rate, 1.87 m per yearwas recorded in the 8 year old plantation and the lowest, 1.75 m was recorded in the 12year old plantation Average number of stems in a plant varies from 1 to 4 stems per plantin all four sites. Average diameter of stems i:l all sites was in the range of 1.8 to 2.1 ern,irrespective of the age of the plantation. The average number of leaves declined with theage of the plantation. In conclusion it is possible to say that although the stem lengthincreases With the age of the plantation, the average growth rate decreases. Average stemdiameter and number of stems in a plant have not shown' any relationship with the age.