Forestry and Environment Sympoisum 2002, Sri Lanka

Wednesday, September 20, 2006

DIFFERENTIAL BIO-ECOLOGY OF ANOPHELINE SIBLING SPECIES: A RELEVANCE TO MALARIA CONTROL IN SRI LANKA

S.N. Surendran 1, B.G.D.N.K. De Silva2 & R. Ramasami3
'Dept. of Zoology, University of Jaffna
2Dept of Zoology, University of Sri Jayewardenepura
3National Science Foundation, Colombo

Human intervention by various means has altered natural ecosystems and thus paved way for emergence of new vectors and their propagation leading to the spread of malaria world wide. Vector ecological studies have been undertaken in order to locate risk areas for malaria and to formulate appropriate strategy for vector control. The prevalence and abundance of mosquito immature stages in various breeding sites reflect the oviposition reference of females and it can be attributed at inter specific and intra specific levels. Knowledge, especially at intra specific level, on bio-ecology of vectors is an essential prerequisite for formulating effective environmental management interventions for the control of malaria.

Morphologically more or less similar but reproductively isolated members of a taxon are termed sibling species and the taxon are species complex. Sibling species exhibit differences with respect to feeding and resting preference, rate of development of resistance to insecticide, susceptibility to parasites and seasonal prevalence.

Among known malaria vectors in Sri Lanka, Anopheles culicifacies, the major vector of malaria, An. Subpictus and An. Annularis, the subsidiary vectors are reported to be existing as species complex in the Indian subcontinent. Studies on the bionomics of the two sibling species B and E of An. Culicifacies in Sri Lanka reveal that these two sympatric populations are diverged in certain bio- ecological aspects which are essential for implementing a successful vector control program. Laboratory infective studies showed that species E could support the extrinsic cycle of Plasmodium vivax and P. falciparum. Studies on the age structure of species B and E revealed that species E has entered the epidemiologically dangerous age. Both siblings showed differential susceptibility to Malathion. Studies on the limnological characterization of larval breeding sites of species B and E showed that species E prevailed in variety of breeding habitats, an indication of high level of adaptive variation of species E. Sibling species status of An. Annularis in Sri Lanka is yet to be revealed. A study on the sibling species of An. Subpitus from a locality in North Western province of Sri Lanka revealed that species B is predominant in coastal and species C in inland areas.

IN VITRO PROPAGATION OF ANTNURlUM (Anfhurium andraeanum L)

S.P.P.WEERASEKARA & Y.M.H.B. YAPABANDARA
Department of Crop Science, Faculty of Agriculture, University of Ruhuna

Callus induction and shoot regeneration were studied using leaf and petiole explants of in vitro cultures of white Anthurium and leaf ex plants of green house grown nine Anthurium cultivars (Cassino, Tropical, SHP, Samangi, Maringue Lady Jane, White, Magic Red and Pierot).

Leaves from in vitro cultures of Anthurium were cultured in MS medium supplemented with 1.0mg/L BA 0,0.2 & 0.5 mg/L IAA and incubated in dark at 25° C temperature. The effect of IAA was significant for callus induction and shoot regeneration. The highest callus quantity (6.75) showed in 0.2mg/L IAA while only 2 shoots regenerated from Omg/1 IAA. Petioles from in vitro cultures of Anthurium were also cultured NIS medium supplemented with combination of 2 levels of BA (1 or 2mg/L) and 3 IAA levels (0,0.2 & 0.5 mg/L). Cultures were incubated in dark at 25° C temperature. Significant differences were found between the two BA levels and 3 IAA levels for callus production and shoot regeneration. The highest callus quantity (5.6) was given in 1mg/L BA with 0.2mg/L IAA than other combinations. Higher shoot regeneration was achieved in 0.2 and 0.5 mg/L IAA with 1 or 2 mg/L BA (2.7-2.9 shoots per explants).

Leaf pieces (lcm*lcm) from green house grown 9 cultivars were sterilized and cultured in MS medium supplemented with l mg/L BA and 0, 0.2 or 0.5 mg/L IAA and incubated dark at 25° C temperature. Significantly higher callus quantity was observed in 0.2 mg/L IAA while the lowest callus quantity was from 0mg/L IAA level. A significant difference was observed among 9 cultivars from callus production. The highest callus quantity (4.74) was observed from the cultivars "Lady Jane" while the lowest callus quantity (1 from cultivar) "Pierot". Shoot regeneration was observed in some cultivars after d-5 months. For example, cultivar "Meringue" produced 3 shoots per explants in 0.5mg/L IAA level and cultivar "Cassino" produced 1 shoot per explants in 0.2mg/L IAA level. Shoot regeneration was not achieved in other cultivars.

COMPARISON OF LONG-TERM TRANSPIRATION OF DIFFERENT TREE SPECIES IN SEPARATE CANOPY LAYERS IN A KANDYAN FOREST GARDEN

W.A.J.M.DeCosta, K.S.P. Amaratunga &
M.R.H.L. Karunasinghe
Faculty of Agriculture, University of Peradeniya, Peradeniya

Kandyan Forest Gardens (KFG s) are a specific vegetation type covering a considerable land area of the Central Province of Sri Lanka. Therefore, water use by KFG s form an important component of the catchment water balance of this area. KFG s consist of a mixture of tree species whose canopies are arranged in different vertical layers.

The study was conducted in a typical Kandyan Forest Garden located at Pilapitiya, Pilimathalawa within the agro ecological region WM2. A vegetation survey was carried out in this garden and it showed 201 trees belonging to 24 different species. Out of these, two tree species were selected to represent upper and middle canopy layers. They were Jak (Artocarpus heterophyllus) and toona (Cedrella toona). Transpiration of these trees was measured as the sap flow in their trunk using thermal dissipation probes. Measurements of the weather parameters were also taken. The incident solar radiation was measured using the tube solarimeters. Relative humidity in the open and inside the KFG was measured by two solid state sensors. The soil moisture content at five soil depths (i.e. 20, 40, 60, 80 and 100 cm) was measured by gravimetric sampling All the data except soil moisture were taken at 30 second time intervals integrated over five minutes and stored in the data logger. The measurements that were taken during the period from 25.12.2001 to 20.02.2002 were analyzed.

Both species showed a similar pattern of daily variation of sap flow. However, the sap flow was substantially greater in Jak than in toona. The total water use of Jak for the experimental period was 3881.25 kg/tree. The corresponding value of toona was 462.83 kg/tree. The upper canopy Jak received a greater irradiance than middle canopy toona. There was a linear relationship between the radiation incident on Jak and toona canopies.

Daily water use of the upper canopy jak showed a clear linear relationship with daily irradiance on its canopy. However, the water use of toona did not show such a relationship. In both species, there were significant negative linear relationships between daily sap flow and daily mean relative humidity. However, air temperature did not have a significant effect on sap flow of both jak and toona trees. The canopy leaf area of jak remained more or less constant during the experimental period, But in toona, the canopy leaf area increased during the latter part of the experimental period. Water use of both jak and toona did not show a significant relationship with the variation of soil moisture content of the top lm of the soil profile. This indicated that the trees were extracting water from the deeper layers of the soil profile. It can be concluded from results of the present study that water use of a KFG is dominated by large upper canopy trees and that it is largely determined by the incident solar radiation. This study also showed that large trees in this ecosystem maintain their high levels of water use even during dry periods of the year by extracting water from deeper layers of the soil profile.

EVALUATION OF GROWTH PERFORMANCES OF SELECTED TREE SPECIES ON

S Subasinghe & Aruna Kumara
Department of Crop Science, Faculty of Agriculture, University of Ruhuna

Five separate field experiments were conducted at Hungama in the Hambantota district, Sri Lanka, to evaluate the growth performances of selected five tree species i.e.Tamarind (Tamarindus indica), Wood apple (Feronoa limonia), Kottamba (Terminalia catappa), Kathurumurunga (Sesbania grandiflora) and Katuandara (Acasia leucoploea) mainly available in the salt-affected areas. Each tree species consisted of six treatments which were differentiated with three potting mixtures (i.e. top soil, sub soil and a mixture of top soil - cattle manure) filled in planting holes and again with mulching and without mulching. The experimental design for a11 experiments were Randomized Complete Block Design (RCBD) with four replicates. Two months old plants raised in poly bags were used in all the experiments. Plant height and dry matter yield of plants were determined as growth parameters, once in three months.

The experimental site was near the Hungama Lake and salinity of the soil is about 9.5 mm hos/cm at topsoil and 8.3 mmhos/cm at 30 cm depth. All the plants have shown good growth performances in all treatments. Growth performances were not significantly affected by mulching for all plant species. Tamarind, Wood apple and Kottamba, which were grown in planting holes filled with subsoil, showed significantly higher growth performances. But in Kathurumurunga, the better performances were observed in the treatment, which used a potting mixture of cattle manure - top soil while in Katuandara, plants grew well in all the treatments irrespective of the treatment effect. Therefore all five tree species, which were used for the experiment, may be recommended as salt tolerant tree species.

Tuesday, September 19, 2006

IMPORTANCE OF IMPROVING BIOLOGICAL ACTIVITY OF TEA SOILS IN SOUTHERN PROVINCE OF SRI LANKA

Keerthi M. Mohotti 1, A. R. Prathapasinghe2, N. G. N. Rasangi 2, Shantha Jayasinghe 1, P. K. Jayawickrema 1 & K. L. Wasantha Kumara2
1 Tea Research Institute of Sri Lanka, Talawakele,
2 Faculty of Agriculture, University of Ruhuna, Mapalana, Kamburupitiya.

The detrimental effects of soil pesticides :au. soil micro biota and biodiversity of the tea ecosystem are poorly understood. In the current study, microbial activity in southern tea soils of Sri Lanka as affected by application of commonly used soil pesticides and certain cultural practices was evaluated by measuring the soil respiration in vitro and in vivo.

CO2 evolution rates in Southern tea soils were generally low as compared to soils in other areas. Herbicide and formalin applications significantly (p=0.005) suppressed the biological activity of Southern tea soils; the nematicide tested was less effective. Incorporation of compost and tea waste significantly (p=0.005) elevated CO2 evolution rate in tea soils than that of in undisturbed, virgin forest soils. Forking strengthened microbial biomass through improved soil physical conditions, Soil biornass was positively correlated with growth of the test plants viz. tea and tomato.

Southern tea soils with low organic matter contents are exposed to repeated application of herbicides and negligence of important agronomic practices due to labor shortage. Such malpractices could aggravate potential build up of pesticide residues in the soil. Thus, improvement of soil organic matter status by incorporation of various organic amendments, establishment of green manure crops, rehabilitation of old tea soils and more importantly, restricted usage of agro-chemicals etc. is essential. These practices will assure long-term sustainable productivity and quality of soils as well as help degrade accumulated chemical residues and elevate densities of soil microbial communities. As a consequence, increased efficacy of bio control of nematodes and soil borne pathogens and proper administration of natural nutrient cycles could be envisaged.

THE APPLICATION OF SUB INDEX AGGREGATION METHOD TO ASSESS THE HEALTH OF A WATER BODY

Lisa Crowley & Niranjali Jayasuriya
School of Civil and Chemical Engineering, RMIT University, Melbourne, Australia

The environmental health of inland water bodies can be described using water quality parameters that describe the physical, chemical and biological status of the water. Each of these parameters reflect different characteristics of the water body and can be assessed by comparing with threshold values detailed in water quality guidelines such as the Fresh Water and Marine Water Quality Guidelines. Assessing the status of a water body using a suite of water quality parameters is cumbersome: and fraught with difficulty, as for a given location some parameters may fall under threshold values whilst others exceed guideline values. To simplify and unify the interpretation based on individual water quality parameters, these can be combined into a single dimensionless number by considering each measured water quality concentration and its corresponding guideline value. This single number is called the `water quality index' (WQI) and is used to assess the overall status of the water body quantitatively and objectively.

Many methods have been derived over the years to determine the WQI for different applications. These methods are grouped into two categories; 'sub-index' and `statistical'. As to-date, no guidelines have been specified on the selection of a methodology. However, it has been acknowledged that the method used to derive the WQI should retain valuable information from each parameter and retain its contribution to determining the overall health during the combining process.

This paper reviews methods available to determine WQIs for a range of applications. The paper will describe the application of the SIA method to a set of water quality data along the Yarra River in Victoria, Australia. The, results were useful in identifying the trend in WQ variation. The Sub Indices Aggregation (SIA) method could be used by Authorities for rapid assessment of water bodies to identify their suitability for different purposes based on the quality of water. Application of the method can also assist with locating critical areas that could urgently require rehabilitation.

ANALYSIS OF WATER QUALITY PARAMETERS IN WELL WATER IN THE VICINITY OF AN INDUSTRIAL ZONE AND ANALYSING SOURCES AND EFFECTS

U.M.S. Priyanka & N.J.G.J. Bandara
Department of Forestry and Environmental Science,
University of Sri Jayewardenepura

The Ratmalana - Moratuwa area located in the south of Colombo has developed as an industrial residential suburb of Colombo in the 1950's. It has been revealed that the environmental problems in the area are very acute due to the activities of large number of industries. About 150 industries arc densely packed, within this area. Most of the industries are non-agro based industries. They can be categorised into several groups such as paint industries, galvanizing industries, asbestos industries, dyeing and finishing, pharmaceutical industries and battery manufacturing industries. According to an investigation of discharges produced in the area was found that major part of the effluent was released via surface drainage to Lunawa and Bolgoda Lake. The main issue associated with this industrial pollution is water contamination. Even though many studies have been carried out on surface water contamination, studies on ground water contamination have not been done in detail. The intention of this study was to, analyze ground water samples at various sites of the industrial zone and to relate the results to the present industrial activities of the area. From these Studies it was found that the chemical oxygen demand (COD), levels far exceed the acceptable portable water quality standards, indicating high chemical pollution. In addition it was found that Chemical pollutants arc present in the ground water. Biological Oxygen Demand (BOD) has exceeded the tolerant limits for portable water level at several locations. The trace metals that exceed the levels are Zn, Fe, Cd, Pb, and Ni which had not been noted in a previous study done by De Silva et al. (1986).

Low pH values-in some of the samples indicate water contamination with acids. Sonic samples have been contaminated with acids and it was revealed by low pH of some samples. Most industries in the area dispose their effluents directly in to the drainage system without any prior treatments. Ground water contamination is thought to be a direct consequence of these inefficient effluent systems. This study discusses the analytical results of water samples taken from various locations of the industrial area and described the industrial activities in the area that might have caused this ground water contamination, and discusses possible health effects due to use of polluted water as a source of portable water in this well water.

QUANTIFICATION OF TOTAL CHROMIUM AND HEXAVALENT CHROMIUM IN WATER BY ELECTROTHERMAL ATOMIC ABSORPTION SPECTROMETRY

B.S. Jayasinghe 1, M.LF.P. Jayawardene 1 & K.A.S.Pathiratne2
1 Department of Biochemistry, Faculty of Medical Sciences, University of Sri Jayewardenepura
2Department of Chemistry, University of Kelaniya

The two primary oxidation states of chromium in natural waters, Cr(III) and Cr(VI), differ significantly in biological, geochemical and toxicological properties. Whereas Cr(III) is considered essential for human in glucose, lipid and protein metabolism, Cr(VI) is toxic because of its ability to oxidize other species and its adverse effects on the lung, liver and kidney. Because of the different toxicities and bioavailability of Cr(III) and Cr(VI), determination of the total chromium content does not give full information about possible health hazard. Hence monitoring of the concentration of the separate chromium species is of great importance. Many different techniques have been in use for Cr containing samples preparation and metal ions speciation: ion chromatography, flow injection analysis, and atomic absorption spectrometry (AAS).

Procedures for the quantification of total chromium and hexavalent chromium in water samples are presented. For the quantification of total chromium and hexavalent chromium in water Chromabond NH2 columns (aminopropyl phase with a 3ml volume and 500mg of sorbent) obtained from Machary- Nagel (Duren, Germany) were used.

The pH value of the water sample was adjusted to 5.5 using acetic acid or sodium acetate and sample was aspirated through the previously conditioned column. The column contents were dried under vacuum and the hexavalent chromium selectively linked was eluted with nitric acid and quantification was performed by Electrothermal Atomic Absorption Spectrometry (ETAAS). For the detection of total chromium, Cr(III) was transformed into Cr(VI) by oxidizing the sample with 1% K2S2O8 solution and AgN03 at 100°C for 15 min. Oxidized solution was eluted through a Chromabond column and total Cr level was quantified by ETAAS using the same instrumental conditions as for hexavalent chromium. Total chromium was also quantified directly in the water samples using ETAAS. The temperature programme of the graphite furnace, the use of chemical modifiers, the atomic technique employed and the effectiveness of deuterium background correction were investigated. Chromium was reliably determined by without chemical modifiers or background correction.

The detection limits were 0.4 and 0.5µg/l for total chromium and hexavalent chromium respectively.. The linearity changed under the optimized conditions was 0.4 - 50µg/l and 0.5-50µg/l and the relative standard deviation was less than 3.5%. The validation of both procedures was performed by the standard addition method and the recoveries were higher than 96% in all cases. It is proved that the method can be successfully employed as an alternative to the commonly used preconcentration and speciation analytical techniques. The direct procedure was adopted for the estimation of total chromium in water samples because both procedures applied for total chromium gave similar results. The methods were applied to the determination of total chromium and hexavalent chromium in 40 water samples.

ASSESSMENT OF THE COMPOSITION AND THE VOLUME OF BIOGAS LIBERATION FROM AGRICULTURAL WASTES

G. Y. Jayasinghe, K. D. N. Weerasinghe, & S. R. W. Pathiranage
Department of Agricultural Engineering, Faculty of Agriculture,
University of Ruhuna

Study was conducted in the Faculty of Agriculture, University of Ruhuna, Mapalana to assess the composition and the volume of biogas liberation pattern from different agricultural raw materials.

In the Sri Lankan batch type biogas. generator (volume 6m3), first batch of straw (1000kg) was filled in September 1999 and second and third batch in October 2000, April 2001 respectively. It was revealed that average gas production from the, digester was 1.0 m3 /day with a peak value of 1.8m3/day. Total gas production during four and half month period of digestion was 166.85 m3. The maximum average methane percentage and the average lag phase during the digestion were 50% and 20 days respectively.

In order to assess the biogas liberation pattern and composition of each material, a laboratory test unit was designed using a 20 L plastic gallon as the digester and experiment was conducted using straw, cow dung and market garbage (vegetable) as raw materials. Gas volumes, pH value of slurry and methane percentage were measured while maintaining the temperature between 35°C-37°C using electric bulbs.

N,P,K compositions, C/N ratio and dry matter percentages of different raw materials were analyzed. Total biogas liberated per unit weight of dry matter was 8.15 L, 58.7 L and 15.797L for dung, vegetable and straw respectively. The duration of digestion period was 55-60 days. Average methane percentages of the liberated gases were 53%, 54% and 50% for dung, vegetable and straw respectively. It was revealed that market garbage had the highest digestibility value, which had the highest gas production with high methane percentage.

Monday, September 18, 2006

AGROA-CLIMATIC POTENTIAL ASSESSMENT FOR CROP INTENSIFICATION IN SOUTHERN SRI LANKA - A CASE STUDY IN MATARA DISTRICT

C.M. Navaratne & K.D.N. Weerasinghe
Department of Agricultural Engineering, Faculty of Agriculture,
University of Ruhuna

The climatic potential in respect to onset, duration and magnitude of the rainfall were assessed using the rainfall probability concepts and the climatic water balance approach. The rainfall data for 45 consecutive years (1950 - 1995) were collected from 10 stations in different agro climatic regions of Matara district. The limits of 10 mm weekly rain at 75% probability and Hargreave's Moisture Availability Index of 0.34 in weekly basis were used to demarcate wet and dry weeks of the area.

The 1st – 10th and the 26th - 36th weeks of the calendar year are recorded as dry weeks in the selected regions except, in Anninkanda. The duration of wet period during Yala and Maha seasons in the selected regions differs from, 1 week to 21 weeks and it is closely related with the mean annual rainfall of the regions. Among all selected regions, the longest wet period is recorded in Anninkanda whereas the shortest wet period is recorded in Kekanadura and Dandeniya.

The onset of rain in Yala and Maha seasons falls during 9th – 20th and 34th - 40th meteorological weeks respectively in all the selected regions. The early onset of rain is expected in the locations where the annual rainfall is high. The duration and magnitude of rainfall increase from south to north and from east to west in the district.

COMPARATIVE STUDIES ON RAPID AND COST EFFECTIVE PROPAGATION METHODS AND INITIAL ESTABLISHMENT OF THE MEDICINAL PLANT Phyllanthus debilis KLIN EX WILLD

K. N. S. Perera 1 & K. U. Tennakoon2
1 Faculty of Applied Sciences, Sabaragamuwa University of Sri Lanka
2Department of Botany, Faculty of Science, University of Peradeniya

Phyllanthus debilis Klein ex Willd. (Sinhala - Elapitawakka) is a widely used annual herb used in Ayurvedic medicine. The main objective of this study was to develop simple and cost effective propagation methods and growth media for initial establishment of P. debilis.

The experimental design was a completely randomized design. Fresh fruit samples at four different stages (light green, dark green, blackish green and brownish yellow) of maturity were used to determine the best maturity stage that gives the highest percentage. Seeds obtained from blackish green fruits gave the highest percentage germination (92 %) when grown on wet filter paper. Percentage of seed germination in dark green and brownish yellow fruits on wet filter paper were 26 % and 65 % respectively and 22 % and 12 % respectively when coir dust: sand (1; 1) medium was used. Seeds obtained from light green fruits did not germinate. Upper and lower stem cuttings of P. debilis showed very low percentage success 2 % and 7 % respectively. Seed moisture content was determined using four seed samples (n = 100) dried at 103*C for 17 hours. The average moisture content of a seed was 15 t 1 %. Hence it can be regarded as an "intermediate" seed type. The seed. viability was tested at weekly intervals for nine weeks. The highest percentage of germination (82 %) was observed in one-week-old seeds. Seed viability decreased gradually over the nine-week period and none of the seeds germinated after nine weeks of storage. Nine different potting media were tested for the initial establishment of P. debilis. Plants grown (n = 20) in the medium comprising top soil: compost: sand (1: 1: 1) performed well in terms of plant height, leaf number and root collar diameter than in the other potting media.

Financial Assistance provided by Sri Lanka Conservation and Sustainable Use of Medicinal Plants Project is gratefully acknowledged.

VEGETATIVE PROPAGATION OF Scyphiphora hydrophyllacea GAERTN F. FOR CONSERVATION

P. L. Hettiarachchi1, P. A. G. W. Premathilake1 & S. Hettiarachchi 2
1 Department of Botany, University of Sri Jayewardenepura
2 Department of Botany, University of Ruhuna


Scyphiphora hydrophyllacea is a highly threatened true mangrove confined to Jaffna and a single locality in private land in Kalpitiya, Sri Lanka. It produces fruits and seeds, but seedlings and young plants are absent ir: the natural habitat. Conservation has become essential and urgent to prevent local extinction of the species. Seed germination using moist filter paper method with habitat water varying from 0% - 100% concentration totally failed in a previous study. This investigation therefore, aims at the possibility of propagating S. hydrophyllacea by vegetative means viz. stem cuttings, girdle cuttings and air layering. Stem cuttings of three stages of maturity (first 5 nodes, 6-9 nodes, 10-13 nodes) were used. Distilled water, water from natural habitat and its 75%, 50% to and 25% dilutions with and without IAA and activated charcoal (0.25g/100m1) were tested for rooting. Further, dipping of the cut base of the cuttings in commercial rooting powders namely Secto containing NAA, Seridox tnd Clonex both containing IBA and different concentrations of IAA (0.5mg/1 -2.0mg/a) prior to leaving for rooting was also carried out. Air layering was done by enclosing one-nuonth-old girdles in moist rooting media (three different mixtures and habitat soil). After one month 50ml of half strength Hogland solution was injected to the medium. Another set of layers were treated by applying a paste of Secto on the trimmed edge of the girdle, mixing the same powder with the rooting medium and injecting IAA to the root ball after one month. Rooted cuttings, girdles and layers were transferred to soil substrate in pots and maintained under green house conditions. Rooting was observed only in distilled water, in both stem and girdle cuttings. There was no significant effect by exogenous IAA and commercial rooting powders. Charcoal improved rooting from girdle cuttings up to 75%. Stage 11 (6-9 nodes from the apex) cuttings gave highest percentage (40%) of rooting. A maximum of 60% of layers had rooted in one month. Use of IAA and rooting powder did not improve the rooting percentage in layers. The plantlets obtained are established in pots in the green house under natural temperature and light. The results satisfactorily show that S. hydrophyllacea can be vegetatively propagated by using, appropriate methods. This is important in conservation, as they do not produce scedlings from seeds. Experiments in hardening of the plantlets to grow in their natural habitat are in progress.

FACTORS LIMITING SEED GERMINATION IN Scyphiphora hydrophyllacea GAERTN f. AND Pemphis acidula J R & FORST


P L Hettiarachchi & R K Jayaratne
Department of Botany, University of Sri Jayewardenepura

Scyphiphora hydrophyllacea is a highly threatened true mangrove confined to Jaffna and a single locality in Kalpitiya (Trillion 1974; Dassanayake and Clayton 1998). Pemphis acidula is restricted to small pockets in few coastal areas. Both produce fruits and seeds nevertheless, seedlings were not observed in their natural habitats. Factors governing seed germination in these two species were studied. For all experiments, randomly collected ripe , seed samples were used within two weeks of collection. Moist filter paper method was used and daily observations were recorded.

In P. acidula, seed production was 100%. Percentage of fruit bearing seeds was 10% in S. hydrophyllacea, but none of them gave rise to healthy seedlings. Seed germination of both species was 0%in water collected from respective natural habitats. In P. acidula %gerrnination was 35% in 75% and 40% in 87.5% dilution of water from natural habitat. In distilled water, 65% of the seeds germinated. Continuous washing of seeds in running tap water increased percentage germination to 75%.

Dormancy breaking treatments such as heat treatment, seed nicking, acid base treatment, cold treatment and treatment with gibberrelic acid did not increase germination above normal 65% value.

Exposure to natural light, photoperiod and oxygen level also affected seed germination. Analysis of data consisted of ANOVA at 5% level of significance using Minitab package. In P. acidula, salinity of soil water (up to 34 ppt) and salt deposits on seed coat seem to be major causes hindering seed germination in natural habitat. Seeds buried in sand may also not receive adequate amount of light (Isikava 1962; Fujii 1962). Oxygen concentration may not be enough when the ground is covered with water during tides. Lack of seedlings may therefore be due to lack of seed germination under natural conditions.

In S. hydrophyllacea, very low percentage of seed bearing fruits and inability to produce healthy seedlings explain why it has become highly threatened. Production of large number of seedless fruits and inability to produce normal seedlings could be due to genetic disorder in seeds, which is a very common pheraorncnon known as inbreeding depression in isolated, small populations.

Presence of self-sterility and the absence of pollinator right be some other reasons. Hence, studies on the possibility of propagating S. hydrophyllacea by vegetative means are urgently needed to conserve this highly threatened tree species.

FACTORS LIMITING SEED GERMINATION IN Scyphiphora hydrophyllacea GAERTN f. AND Pemphis acidula J R & FORST


P L Hettiarachchi & R K Jayaratne
Department of Botany, University of Sri Jayewardenepura

Scyphiphora hydrophyllacea is a highly threatened true mangrove confined to Jaffna and a single locality in Kalpitiya (Trillion 1974; Dassanayake and Clayton 1998). Pemphis acidula is restricted to small pockets in few coastal areas. Both produce fruits and seeds nevertheless, seedlings were not observed in their natural habitats. Factors governing seed germination in these two species were studied. For all experiments, randomly collected ripe , seed samples were used within two weeks of collection. Moist filter paper method was used and daily observations were recorded.

In P. acidula, seed production was 100%. Percentage of fruit bearing seeds was 10% in S. hydrophyllacea, but none of them gave rise to healthy seedlings. Seed germination of both species was 0%in water collected from respective natural habitats. In P. acidula %gerrnination was 35% in 75% and 40% in 87.5% dilution of water from natural habitat. In distilled water, 65% of the seeds germinated. Continuous washing of seeds in running tap water increased percentage germination to 75%.

Dormancy breaking treatments such as heat treatment, seed nicking, acid base treatment, cold treatment and treatment with gibberrelic acid did not increase germination above normal 65% value.

Exposure to natural light, photoperiod and oxygen level also affected seed germination. Analysis of data consisted of ANOVA at 5% level of significance using Minitab package. In P. acidula, salinity of soil water (up to 34 ppt) and salt deposits on seed coat seem to be major causes hindering seed germination in natural habitat. Seeds buried in sand may also not receive adequate amount of light (Isikava 1962; Fujii 1962). Oxygen concentration may not be enough when the ground is covered with water during tides. Lack of seedlings may therefore be due to lack of seed germination under natural conditions.

In S. hydrophyllacea, very low percentage of seed bearing fruits and inability to produce healthy seedlings explain why it has become highly threatened. Production of large number of seedless fruits and inability to produce normal seedlings could be due to genetic disorder in seeds, which is a very common pheraorncnon known as inbreeding depression in isolated, small populations.

Presence of self-sterility and the absence of pollinator right be some other reasons. Hence, studies on the possibility of propagating S. hydrophyllacea by vegetative means are urgently needed to conserve this highly threatened tree species.

INVESTIGATION OF THE EFFECTIVENESS OF MOTHER ENZYME ON MODEL ORGANIC WASTE MATERIAL BY ENZYME DEGRADATION

A.G. I . I . Wimaladharma1, N.J.G.J.Bandara1 & A.H.D.O. Bammunuarachchi2
1 Department of Forestry and Environmental Science, University of Sri jayewardenepura
2 Department of Chemistry
University of Sri Jayewardenepura


Continuous disposal of solid waste arid their collection creates a severe environmental and health hazard. In Sri Lanka the major percentage of municipal solid waste is organic waste. Hence, one-way of over coming this problem is to increase the rate degradation of organic material in which enzyme and microorganisms play a big role. Mother Enzyme (ME) is said to be one such mixture of enzymes and microorganisms.

Objectives of this research was to identify the constituents of the ME, to determine the effectiveness of the ME on degradation' of different types of organic wastes, and to determine the effective levels of ME for different types of organic wastes.

Macconkey agar, Nutrient agar and Sabouraud Dextrose Agar were used to find the total number and the types of microorganisms present in the ME. Effect of Mother enzyme an different of organic waste were done by using Farm (cattle and poultry) waste, kitchen wastes and fruit industry wastes in the presence and in the absence of ME with replication. Weight reduction with time was noted down. To estimate the effect of ME on model organic waste, wheat flour, egg yolk and coconut oil were used. Alanine, Glucose and Acid value estimation were done to estimate the rate of degradation of the macromolecules in the presence of and in the absence of ME. In order to find out the effective levels of ME farm (cattle and poultry), kitchen wastes and fruit industry wastes were used with replication. 2g/lkg and O.5g/lkg of mother enzyme was introduced and weight reduction was noted down.

Form the Microbiological analysis, Staphylococcus aureus, Esscherichia colli, and Mucor, were found to be present in ME and the total number of organisms present was 13x10-14 .

From the study it was revealed that the break down of model organic matter - fats and proteins occur quite fast in the presence of another enzyme. But mother enzyme does not significantly increase breaking down of carbohydrates.

Increased or decreased levels of ME have no significant effect on mixed organic wastes. Due to our consumption pattern most of organic wastes generated in Sri Lanka are of carbohydrate origin. This may be the reason why there is no significant effect due to ME on mixtures of organic wastes found in Sri Lanka.

FUTURE OF BITUMEN EMULSION AS-AN ENVIORNMENTAL FRIENDLY ROAD CONSTRUCTION MATERIAL

H.L.D.M.A. Judith & J.M.S.J.Bandara
Department of Civil Engineering, University of Moratuwa.


Bitumen emulsion is a thermodynamically unstable- heterogeneous system in which finely ground bitumen particles are dispersed in an aqueous medium. In most parts of the world usage of bitumen emulsion as a road construction material has increased during the recent past partially replacing penetration grade bitumen (tar) and cutback bitumen due to environmental reasons. In Sri Lanka bitumen emulsion is used for certain road construction work. However, still there is somewhat reluctance among road engineers to use bitumen emulsion as a substitute for other types.

There are numerous uses for bitumen emulsion utilizing highly varied techniques, which results in several different formulations; namely cationic and anionic depending on particle charges and rapid setting, medium setting and slow setting depending on its speed of separation of bitumen from aqueous medium. In Sri Lanka, cationic type bitumen emulsion is used, as majority of the available local aggregates are acidic except Jaffna limestone.

Bitumen emulsion is suitable to the requirements of all road maintenance work. Ease of storage and transport make it possible to set up numerous depots and its ease and facility of use enable work to be done quickly causing minimum disturbance to the users. It may be the first choice bituminous material for all maintenance work on road pavements due to environmental friendliness, provided that correct proportions and standard specifications are being used.

Bitumen emulsion has proven itself as a binder, which utilizes very low energy consumption in road maintenance and laying of surface dressings. Penetration grade bitumen requires heating at construction sites, which emit smoke with chemicals and also it needs fuel, which is a non-renewable resource. Kerosene that is used for cutting back the viscosity of bitumen is also a non-recoverable waste when curing takes place on the road.

This paper identifies the advantages of using bitumen emulsion over other traditional alternatives and investigates the reasons for the reluctance to use locally. The paper proposes suitable remedial measures to overcome the perceived disadvantages and increase the use of bitumen emulsion as an environment friendly alternative.

DEVELOPMENT OF AN ENVIRONMENT FRIENDLY METHOD TO REMOVE THE COLORED COMPONENTS FROM INDUSTRIAL WASTE WATER

Dinesh Pandithawidansa & K.R. Ranjith Mahanama
Department of Chemistry, University of Colombo

Nowadays, synthetic dye context is a vital component in the textile and dyeing industries. The garment factories in the free trade zone that are discharging dyes and other coloured compounds into waterways pollute the environment. In this project, attempts were made to design an environment friendly methodology to degrade Azo dyes by means of Eco-­efficient techniques. Optimum conditions were evaluated for the redox-degradation of the Azo dye; and some of the dyes that are used in garment industry. The fidelity of the proposed mechanism was confirmed by the; spectroscopic and GC analyses. As a reducing agent, metallic iron has fulfilled all the requirements that are prescribed for green chemical concepts.

The results presented in this report clearly demonstrate that Anthroquinone-2-sulphonic acid is a powerful catalyst, capable of ,accelerating the reaction rate by orders of magnitude. The powdered form of charcoal amalgamated with metallic iron has facilitated as a better substrate to adsorb the dye component improving the contacts of reactant molecules with the catalyst and dye molecules. The experimental results revealed that pH 4 is the optimum condition for the redox degradation of the dye, which is confirmed by electrochemical, and thermodynamic calculations. The elevation of the reaction temperature has accelerated the reaction by several orders of magnitude. To demonstrate the applications in real world; a continuous flow reduction apparatus was designed and constructed.

HIGH RATE BIO METHANATION OF MUNICIPAL SOLID WASTE

Upali Wanigaratne, Sanja Gunawardena, Kapila Perera & Ajith De Alwis
Department of Chemical and Process Engineering,
University of Moratuwa

Growing urbanization and industrialization have led to the generation of large quantities of solid wastes, which can be broadly classified as MSW (Municipal Solid Waste) and ISW (Industrial Solid Waste). Among the options available for solid waste management, biomethanation appears to be the most desirable because it is a technology with triple benefits yields biogas which can replace conventional fuels, provides digested sludge which can be used as a soil conditioner and manages the environment.

This work involved the development of a three-stage leachate based bioreactor system for solid waste management. The first stage involves extraction of high organic strength (high in chemical oxygen demand - COD) liquid called leachate from the solids. This stage is known as the hydrolyzing stage. Acid formation takes place in the second or the acidification stage in a separate reactor known as the acidification reactor. Biogas is generated by treating the acidified leachate in an upflow anaerobic filter (AF) reactor in the third (or the methanation) stage.

Three stage anaerobic systems are increasingly finding its place in biogas generation. Two kinetically dissimilar groups of bacteria, acetogenesis and methanogenesis are physically separated in acetogenic reactor and methanogenic reactor. This separation allows optimization of both acetogenesis and methanogenesis stages making the process control easier.

In this method, the organic solid waste is cut into small pieces, fed into the hydrolyzing reactor with water and circulated at a fixed rate to wash off organic acids formed until high organic strength is obtained. This is then fed in to the acidification reactor. The acidification phase has retention time of 6 days. Anaerobic conditions prevail inside the reactor during the whole process. The residue left inside from the first reactor is subjected to drying for manure preparation.

The final concentrated leachate obtained after G days is fed in to the AF reactor for methanation. This phase has retention time of 5 days. The microbial consortia present in the AF sludge destroys high amount of COD, forming biogas comprising of 65% - 75% methane. This system is economically viable, the total space and the time required for the process is low compared to conventional single­ phase processes that takes 30-40 days. The system has low water consumption because of the reuse of the AF reactor overflow to the acidification reactor.

AN INVESTIGATION INTO THE ECOTOURISM DEVELOPMENT POTENTIAL IN ILLUKKUMBURA AREA IN THE KNUCKLES RANGE

C. Maelge & D.M.S.H.K.Ranasinghe
Department of Forestry and Envirobmental Science,
University of Sri Jayewardenepura

Knuckles National Heritage Wilderness Area is approximately 155 km2 and is located in the Central Province of Sri Lanka. Knuckles forested area has high endemic biodiversity and possesses a rich cultural history. !It falls under the administration of the Forest Department, The area has been separated into three different zones, for systematic implementation of ecotourism activities. Illukkumbura is one such ecotourism zone of the Knuckles forested area.

Objectives of the study are to explore the ecotourism development potential of Illukkumbura area, promotion of local. community participation in ecotourism and recommendation of strategies to promote Illlukkumbura area in the global tourism market. Comprehensive literature survey was conducted to gather secondary data, with regard to ecotourism and its subject matter. Primary data was collected initially through a reconnaissance survey, to demarcate the study site, familiarize with key decision makers of the villages and provided the basis to select the study area and participant for the Participatory Rural Appraisal as well as decide on the time duration of the Participatory Rural Appraisal. To gather in depth primary data Participatory Rural Appraisal was conducted in the selected villages, with a questionnaire assisted interview process. The respondents were selected using random sample techniques, which comprised of SU participants. Field observations were carried out in all ecotourism attractions at Illukkumbura area. Specific attention was given to the site selection for suitable ecotourism activities, especially suited for various ecotourists.

Study revealed that Illukkumbura zone is patronized by tourist both domestic and foreign at present mainly for trekking, swimming and camping. Study resulted in evaluating the importance of the each nature trail for ecotourism, exploring other ecotourism sites in the area, exploring the potential of community participation in ecotourism, developing a communication strategy for the area and drawing up proposed guidelines for a ecotourism development plan in the Illukkumbura area. Recommendations were made in line to promote continuous research with relation to ecotourism and adapt better management ecotourism practices for sustainable development.

FORMULATION OF SUSTAINABLE AGRO FORESTRY MODELS FOR NORTH CENTRAL DRY ZONE OF SRI LANKA

U. Lakshmani1 & D.M.S.H.K.Ranasinghe2
1 Department of Agriculture
2 Department of Forestry & Environmental Science,
University of Sri Jayewardenepura


Increase of human population and clearing of forests for their requirements has been a local as well as global environmental crisis. In Sri Lanka, forest cover has dwindled at an alarming rate from 70% in 1990 to 22% as of present. Deforestation and degradation of land due to many reasons including poverty related land management practices such as shifting cultivation and forest encroachments, conversion of forest estate to other more economically profitable land uses are some of the reasons for the loss of forest. Agroforestry has been identified all over the world as an appropriate alternative which provides sustainability.

According to the Forestry Sector master Plan (1995) the necessity of utilizing the sparsely­ used scrub lands for agroforestry ventures to improve the tree cover and socio-economic status of the people has been identified. Forest Department too in its Participatory Forestry Project has ventured into establishment of farmers woodlots with the active participation of communities and this programme is wide spread in many parts of the country especially in the dry zone. However, the composition of these farmers woodlots still not complete to incorporate diversity and sustainability. Therefore, the objective of this present study is to formulate sustainable tree-crop models for a wide range of land classes in the north central dry zone of Sri Lanka.

Ipalogama divisional Secretariat in Anuradhapura District was identified for the study. Field studies were done in handsomely selected 3 traditional tank based villages namely Sangattewa, Puliyankulama and Dampeleassagama. Information was gathered through a questionnaire survey, field visits and personnel interviews with villagers. Randomely selected 44 households or 14.8% of the total households in the 3 villages were subjected to the survey. The species composition and vertical and horizontal diversity, light requirements, multiple uses, financial returns/ha, prevalence of local/indigenous tree species and farmer's choice were taken into consideration in the formulation of the agroforestry models for the various land classes sampled e.g. Alluvial plains, middle slopes and upper slopes etc.

EVALUATION OF SLOPING AGRICULTURAL LAND TECHNOLOGY (SALT) AS A MEANS OF ENSURING SUSTAINABILITY OF TEA YIELDS IN THE UP- COUNTRY WET ZONE (WU2) OF SRI

W.A.J.M. De Costa & P. Surenthran
Department of Crop Science, Faculty of Agriculture, University of Peradeniya


Sloping Agricultural Land Technology (SALT) is a system of land management that has been introduced to arrest the decline of soil fertility and sustain yields of tea plantations on sloping terrain in the central highlands of Sri Lanka. SALT involves the incorporation of fast-growing, mostly leguminous tree species as hedgerows along contours at pre-determined distances among tea rows. 'The hedgerows are expected to increase soil fertility by reducing erosion and providing organic matter through frequent addition of prunings. However, SALT hedges could compete with tea for essential growth resources such as water, nutrient and light and consequently reduce tea yields. Therefore, the main objective of this study was to quantify the positive and negative effects of SALT hedges and to determine their net impact on tea yields and parameters of soil fertility.

Two long-term, on-farm field experiments were conducted at Helbodde Estate, Pussellawa in the Up-Country Wet Zone (WU2). The effects of six tree species (Calliandra calothyrsus, Cassia spectabilis, Euphatorium innulifolium, Flemingia congesta, Gliricidia sepium and Tithonia diversifolia) growing as contour hedgerows on the long-term yields of mature tea (i.e. in the second pruning cycle) and young tea (i.e. first pruning cycle) were quantified in Experiments 1 and 2 respectively. These experiments also measured the yield response to the addition of mulch material. from different tree species. Continuous yield measurements were done at weekly intervals since November 1998.

Continuous tea yield measurements that were done at weekly intervals were compiled and analyzed over a three-year pruning cycle from November 1998 to October, 2001. In Experiment 1, yield of mature tea growing with Euphatorium hedgerows was significantly greater titan the yield of tea growing without hedgerows (i.e. control plots). However, yields of nature tea growing with all other laadgerow species were significantly lower than in the cor.trol. Mature tea yields of all hedgerow plots increased significantly in response to the addition of the respective hedgerow prunings as mulch. These results show that although all hedgerow species contribute to the improvement of soil fertility, all hedgerow species except Euphatorium exert significant resource competition, which exceeds their respective positive fertility effects. In Experiment 2, yields of young tea growing with all hedgerow species, including Euphatorium showed significant reductions as compared to the yield of sole cropped young tea. This shows that young tea is less able to withstand resource competition from hedgerows than mature tea. However, in Experiment 2, the least yield red action was shown in tea growiag with Euphatorium. Among the different hedgerow tree species tested, Euphatorium showed the highest yield increase due to the addition of prunings as mulch in both'experiments.

IMPROVEMENT OF SOIL CHARACTERISTICS UNDER CROP - STOCK INTEGRATION

S.H.R. Priyadarshani & Thakshala Seresinhe
Dept of Animal Science, Faculty of Agriculture, University of Ruhuna

Soil characteristics and vegetation properties of Diggassawela farm belong to Diddenipotha plantation Limited (approximately 10 km from Kamburupitiya) was studied in view of evaluating the impact of crop - stock long term integration. Crop - stock integration has been practiced in this farm for more than a decade. Compost and farmyard waste were intensively used for tea replanting purposes and pasture cultivation respectively. Soil samples were collected randomly from (3 replicate/location) cattle courtyard, pasture land and compared with an abandoned tea land soil in the same area.

The soil pH ranged from 8.06 for pastureland and 4.53 for an abandoned tea land (P <>0.05). The soil characteristics of pastureland compared with other two sites shows improvement due to nutrient recycling via dairy washings and litter accumulation.

The observations also revealed that the grass yield and longevity of the pastures and fodder were improved significantly with application of farmyard waste. Application of compost also improved the soil properties and increased the rate of survival of tea plants (replanting).

The results suggest that the waste materials such as excreta, residues of feeding materials, bedding and dairy washings thus produced various benefits with passage of time and demonstrated potential for the sustainability of a crop - livestock integration system. It is suggested that crop - livestock integration could be successfully used for the rehabilitation of tea lands on a long-term basis.

SPECIES COMPOSITION AND SOIL CHARACTERISTICS BETWEEN GRAZING FORAGE SYSTEMS AND CUT AND REMOVED FORAGE SYSTEMS IN WALAWE REGION

S.N. Muditha Manjula & Thakshala Seresinghe
Department of Animal Science, Faculty of Agriculture, University of Ruhuna

Botanical composition and soil parameters of grazing and cut and removed forage systems in five villages (Barawakumbuka, Manadala, Nonagama, Bolana, Ambalantotoa) Walawe region were studied to observe the impact of different management systems on the productivity of plant and soil characteristics. Herbage and soil samples were collected randomly using a quadrate (50*5Ocm2) from five grazing and five cut and removed sites. Samples (3 replicates) were collected three times from each locations during the following periods. Herbage from grazing lands consisted 85% grasses and 15% other species. Prostrate grass species such as Eleusine indica and Chrysopgon aciculatus, were dominant and improved groundcaver. Moisture (20.04%) retention in the grazed soil was significantly increased due to the improvement of ground cover with increasing the potential for soil conservation. Herbage collected from cut and removed sites consisted 70% grasses and 30% other species.

Dominant plants were tufted species such as Pennisetum polystachyon; Grewia corpinifolia and Leucaena leucocepha. Moisture (6.13%) retention in these sites was significantly lower as compared with grazed sites.
Soil collected from grazing sites had higher pH (7.88) as compared to the cut and removed sites (6.13). This may be due to recycling of nutrients via dung and urine. Threading by animals, which may cause a packing of the soil particles and loss of the large pores in the soil mass increased the bulk density (1.34 g/cm3) of the grazing sites as compared with the soil of cut and removed sites (1,16 g/em3). This would have been reduced the porosity of the soil in grazing sites (24.96%) as compared to the soil in cut and removed sites (46.86%). Although the bulk density of the grazing soils was negatively affected by threading, ground cover, moisture retention and spatial redistribution of mineral nutrients are influenced by grazing management as compared with cut and removed systems. Therefore, it can be suggested that grazing management is more suitable for low input output subsistence farming systems in the Walawc region.

Sunday, September 17, 2006

GROWTH PERFORMANCE OF LARGE DIAMETER RATTAN (Calamus) PLANTED UNDER PINE PLANTATIONS AT SINHARAJA BUFFERZONE.

H. S. Gammanpila1, B.M.P. Singhakumara1 & P.M.S. Ashton2
1 Department of Forestry and Environmental Science,
University of Sri ,Jayawardenepura
2 School of Forestry and Environmental Studies, Yale University, USA.

Rattans can be considered as the most important non-timber forest product. Due to heavy exploitation from the wild, the resource is declining at an alarming rate. The present study examined 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 three large diameter rattan species, namely Calamus zeylanicus Becc., Calamus thwaitesii Becc., and Calamus ovoideus Twa. ex Trim, planted under pine plantations in the buffer zone of Sinharaja, Sri Lanka. Four sites of rattan plantations in ages, 8, 9, 10 and 12 years were selected with each site consisting of five plots. Lengths of stems were estimated and stem diameter was measured without the sheath. Number of live leaves and stems in a clump were counted in each plant. Number of pine trees of each site was counted and soil analysis was carried out to depict the site quality.

The highest stem lengths were recorded in the oldest site and the highest mean height recorded after 12 years was 20 m. Results showed that the height increases with the age and the average growth rate decreases. The highest average growth rate, 1.87 in per year was recorded in the 8 year old plantation and the lowest, 1.75 m was recorded in the 12 year old plantation. Average number of stems in a plant varies from 1 to 4 stems per plant in all four sites. Average diameter of stems in all sites was in the range of 1.8 to 2.1 cm, irrespective of the age of the plantation. The average number of leaves declined with the age of the plantation. In conclusion it is possible to say that although the stem length increases with the age of the plantation, the average growth rate decreases. Average stem diameter and number of stems in a plant have not shown any relationship with the age.

IMPACT OF SAMBAR DEER (Cervus unicolor unicolor) ON THE VEGETATION AT THE HORTON PLAINS NATIONAL PARK

L.K.Rajapakse 1, U.K.ta.K.Padmalal 1 & S.W.Kotagama 2
1Department of Zoology, The Open University of Sri Lanka
2Department of Zoology, University of Colombo

A survey was carried out at the Horton Plains National Park to investigate the influence of sambar deer on grassland and forest vegetation., The method adopted was, comparison of the dominant grassland communities, and seedlings in the forested areas with and without the effect of deer. Three enclosures (20 m x 5 m) were erected in the grassland and four enclosures (20 m x 15 m) were erected in the forest to serve as controls (no grazing). Similar areas adjoining the plots were marked with pegs as test areas (with grazing). Field surveys were carried out during the years 1997 and 1998. Incidence and extent of bark damage by sambar deer was also examined using a scoring method on six transects each measuring 250 m. GSN (Grazing Susceptibility Number) was used as an indicator of the the phytosociological behaviour of sambar in the grassland. Summed Dominance Ratio (SDR) was used to calculate the GSN. During the months of January, March, July and October 1997, GSN values for dominant species in the grassland viz Pennicetum and Chrysopogon were 18.4, 20, 23.75, -3.06 and 18.6, 8.1, 17.23, 19.0 respectively. The minus GSN value of 3.06 indicates that during October Pennicetum grass was not damaged by deer which coincided with the flowering period of that species. Grazing pressure values obtained during the periods July-Sep 97, Sep-Nov 97 , Nov-Jan 98, Jan-Mar 98 for Pennicetum and Chrysopogon were 1.7, 5.6, -17.6, 5.8 and 1, 1, 1, -0.5, 0.9 respectively. Here the minus values indicates heavy grazing. During the periods of less rain and also during peak lactation periods of sambar, the grazing pressure is high (July-September and November-January) compared to positive values of grazing pressure which coincides well with the comparatively high rainfall periods. Studies of the forest vegetation revealed that after a period of two years (1997-1999) 88% of seedlings survived (N=1499) in the enclosure but only 73% of the seedlings survived (N=1488) in the open area. Bark damage is distinct an plants like Cinnaniolnum ovalifolium, Neolitsea fucata, Calophyllum walkeri, Eurya japonica, Eleocarpus subvillosus, Syzigium revolutum, and Hedyotis lawsoniae all of which have high IVI (Importance Value Indices). Trees with average dbh 28 cm and average height 7 m were more prone to damage by deer. Only 5% of a total of 921 trees were dead due to bark damage.

Thursday, September 14, 2006

ESTIMATING THE ABUNDANCE OF SAMBAR DEER( Cervus unicolor unicolor) AT THE HORTON PLAINS NATIONAL PARK Of SRI LANKA

LK.Rajapakshe 1, U.K.G.K. Padmalal 1, S.W. Kotagama 2 & N.K. Athulathmudali3
1Department of Zoology, The Open University of Sri Lanka
2Department of Zoology, University of Colombo
1National Zoological Garden, Dehiwala

A study was conducted during the period 1997-2000 to estimate the sambar population at the Horton Plains National Park of Sri Lanka using direct and indirect method. Vehicle based spot light technique was used as the direct method and fecal accumulation method was used as the indirect method. The defecation rate of sambar used in the indirect method was estimated by, a study carried out in the National Zoological Garden Dehiwala, using eight-penned sambar. The mean defecation rate of sambar deer for the eight focal sampling at the Zoological Garden - Dehiwala was twenty-one pellet groups / sambar/ day (range = 20,17- 30). Results of ANOVA revealed that there is a significant variation in defecation rate with age (P<0.05, sig-0.02)but it is not significant sex (P<0.05, Sig-0.09)
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Altogether 688 transects were run for the direct method. For the indirect method, 200 quadrats measuring 25m*25m size were sampled. Standard equations were used for the population analysis. The estimated sambar population, crude density and ecological density of the direct and indirect methods are 2102.5=B1845, 66.5/km2, 223.5/km2 and 3154=B 11096, 98.9km2, 350/km2 respectively.

Results indicated that the values obtained by the indirect method are higher than the values obtained from the direct method. The reliability of the indirect method depends on the actual daily defecation rate of sambar deer, which depends on the habitat use. Direct methods are more reliable but not feasible at all times. However indirect method can be used to obtain information on population trends. The results of this study indicate an increase in sambar deer population at the Horton. Plains National Park when compared with estimates made in 1991.

BIO DIVERSITY IN THE CLOUD FORESTS OF THE KNUCKLES RANGE

D.R.N.S. Rajapaksha 1 & V.A.M.P.K. Samarawickrama2
I University of Peradeniya
2 IUCN -The World Conservation Union

The Knuckles Mountain Range is situated in the Intermediate Zone between the latitudes 70°18'-7034' and longitudes 80°41'-80 55' within a 915-1906m elevation range in the Matale District. The slopes directly exposed to monsoon winds receive a high amount of rainfall (2725-4470 mm) per annum. Temperature in the area ranges between 25°C and 27°C at lower altitudes and 18 C-20 C at higher altitudes.

Data were collected in the two localities Nawanagala and Deenston Nature trail in the sub­
montane 2002and montane forests on the west facing slopes from 6 a.m. to 6 p.m. on 17th-18th August 2002.

The trees are low in stature (Syzyium sp.), Rutaceac (Toddalia sp.), Clusiaceae (Calophyllum sp.), Orcltidaceae (Eria bicolour) and Liliaceae (Asparagus sp.). The total number of species observed exceed 35.

The animal life is highly diveres too. The total number of species identified in study area was 124 with 67 bird species (9 endemic), 2 fish (1 endemic), 20 butterflies (2 endemic), 16 mammals (4 endemic), amphibians (6 endemic) and 19 reptiles.

The Nawanagala and Deenston nature trail are unique areas of island's bio diversity heritage. There are more plant and animal species, especially amphibians yet to be identified. The area faces the threat of periodic fires triggered by People. Moreover, the Deenston nature trail experiences the problem of garbage. Therefore, the bio diversity of this unique area has to be conserved for future generations.

BEHAVIOR OF Ceratophora tennentii GUNTHER,1834 IN RELATION TO AMBIENT TEMPERATURE IN A SELECTED HABITAT !N KNUCKLES FOREST RANGE OF SRI LANKA

P.R.K. Rodrigo1, U.K.G.K. Padmalal 1, LU.P. Samaraweera 1 & J. U. L.D. ayantha 2
1 Faculty of Natural Science, The Open University of Sri Lanka
2 Faculty of Veterinary Medicine and Animal Science,
University of Peradeniya

A research was conducted in the eastern slope of the northern flank of the Knuckles forest range for a period of 3 months from March - June 2002 with the objective of studying the general behavior of C. tennentii related to the ambient temperature. Data was collected for a period of 10 days between 0800 to 1800 hrs using focal sampling method. Juvenile (J), male (M) and female (F) lizards were observed and the ambient temperature of the substrate used in the habitat was recorded. An average temperature in the study site fluctuated from 16.80°C in the morning, 24.25°C at noon and 16.25°C in the evening. Activity of all lizards was high around noon (1100-1300 hrs) and it was observed that they are relatively inactive in the morning and evening when the ambient temperatures were minimum. All the groups spent more time on resting (J = 50.83%, M = 42% and F = 55.83%). The most preferred substrates were tree trunks and cardamom plants (J = 34.3%, 33.5%; M = 37.3%, 28.2%; F = 13.5%, 32.2% respectively). It can be concluded that the general behavior of C. tennentii correlates with the ambient temperature where a high degree of activity was observed during the daytime. The optimum range could be 20°C­- 24°C for captive management of these lizards. They preferred substrates exposed to sunlight such as tree trunks and cardamom plants where there were numerous insects during the flowering season.

DISTRIBUTION OF SNAKES IN HANTANA RANGE AND PERADENIYA UNIVERSITY PARK

V. A. M.P.K. Samarawickrama, V Chandrasegaran & K.B.Ranawana
Department of Zoology, Faculty of Science, University of Peradeniya

Sri Lanka is blessed with a diverse serpentine fauna, and the island harbours 93 snake species in 46 genera and 26 families.
Seven major habitat types namely Grasslands, Natural forest patches, Streams and water ways, Pinus plantations, Riverine forests, Agricultural lands, and managed landscape in the Hantana range and Peradeniya University Park were surveyed for six months from November 2001 to April 2002. Day arid night-time survey was carried out to locate snakes and to record their microhabitats. Species identification was done in the held and photographs of snakes were taken whenever necessary.

Twenty snake species (25% of the total; including six endemics were recorded from the seven sites during the survey. Highest number of species (16) was recorded from the grasslands. Agricultural lands, Riverine forests and Natural forest held the second highest number of species with nine and eight respectively. The number of species in the grassland represents 30% of the total number present in the country.

Hantana Range and the University land are subjected to severe degradation due to human activities. The natural forests have reduced to a greater extent due to the illegal felling, and the grasslands and Pinus plantations are subjected to annual fires. Therefore, the most snake species found in the grasslands are heavily threatened. Study and planning programs should be initiated to conserve the diverse habitats types in the area to protect and conserve the diverse snake fauna of the area.

SUPPORTING THE SRI LANKAN NATIVE BIRD SPECIES JUNGLE FOWL IN ANALOG FORESTRY

AM Lokuge & K.L.G.H. Sanjeewa
Neo Synthesis Research Station

An experiment done at model Analog Forestry of Belipola Estate, Mirahawatte, Sri Lanka indicates that an array of native and exotic crops determined by studies and trials made jungle fowl to re-establish, carry out main life activities and thrive in this of proper design.

FINANCING FOR SUSTAINABLE DEVELOPMENT: SOLUTIONS OF WORLD SUMMIT ON SUSTAINABLE DEVELOPMENT

Thosapala Hewage & B.M.S Batagoda
Ministry of Environment and Natural Resources

The World Summit on Sustainable Development (WSSD) held in Johannesburg, South Africa 2002 has given significant priority to finance and trade issues since funding has been identified as key constraints for the implementation of Agenda 21. The Summit adopted some ambitious programs specifically for poverty eradication such as halving the proportion of the world's people whose income is less than $1 a day, proportion of people who suffer from hunger, proportion of people who are without access to safe drinking water and sanitation by 2015. Obviously, the implementation of all its decisions depends on the success of addressing development finance issues that covers a vast range, from official development assistance to Commercial loans by multilateral financial institutions and private banks, foreign direct investment, domestic credits, investment and government transfers. The objective of this paper is to investigate whether the WSSD presents a solution to the financing for sustainable development taking Sri Lanka as a case study.

The study observed that between 1992-2000 Official Development Assistant (ODA) has fallen steadily from 0.33 % of donor country GNP to 0.22 % although at the Earth Summit developed countries agreed to provide 0.7% of GNP as ODA. This decline has affected the least developed countries (LDCs), who are highly dependant on ODA, which constitutes on the average almost 90% of their total long term capital inflows. However during this period, Foreign Direct Investment (FDI) has significantly increased. FDI to developing countries has increased from US$ 36 billion in 1991 to US$ 185 billion in 1999, but declined to US$ 175 billion in 2000. This is however is only a small portion of the global FDl flows, which amounted to US$ 1.1 trillion in 2000. In 2000, 80% of FDl went to only ten developing countries and LDCs attracted only 2.5 % of all FDI flows to developing countries. In Sri Lanka, foreign direct investments have dropped from US$ 129 Mn in 1977 to US$ 82 Mn 2001. Total outstanding foreign debt has rose from Rs. 235,358 Mn in 1992 to Rs. 634,622 Mn in 2001. This indicates serious debt crises in developing countries, which is not a favorable condition for attracting further FDI to developing countries.

At the same time measures taken by the international community to treat the excessive debt burdens of 41 heavily indebted poor countries (HIPC) have not delivered the expected results. Thought the IMF and the World Bank have approved debt reduction programs for 22 countries in December 2000, only Uganda was able to clear the prerequisite the creditors. This evidently suggests that the proposed financing measures at the WSSD will also face implementation problems. Unless all debtors and creditors work positively without demanding unreasonable prerequisite for debt relief measures, the objectives of the WSSD cannot be achieved.


EVALUATION OF POLLUTION DAMAGE COST IN BELLANVILA ATTIDIYA WETLAND

S.H.B.N.P. Herath & U.A.D.P. Gunawardene
Department of Forestry and Environmental Science,
University of Sri Jayewardenepura

Management of waste, both liquid and solid has become a critical environmental concern particularly in the more urbanized areas in Sri Lanka and this problem is most severe in the densely populated areas of Western province. Bellanwila Attidiya wetland is also one of the places, which is used as open dumpsites. It has bad effects on the health, air quality, bio diversity water, and land.

The main objective of the present study was to evaluate the pollution damage cost of the wetland. In addition peoples views were also obtained on possibility of recreation in the wetland.

In the present study the Contingent Valuation Method was used to evaluate tile pollution damage cost of the wetland. Data was derived from a Contingent Valuation survey carried out among the residents of the area and commuters who travel along the road which passes through the wetland. The results were consistent with theory and an aggregate cost of wetland pollution was estimated to be 2870.00 million rupees per year. People expressed their willingness for proposals of developing the wet land as a recreation site.

The valuation may be useful in cost benefit analysis of wetland management and other related policy and planning programmes related to wetlands. This could be used as an instrument to get the local and international attention and draw funds for the wetland conservation.

ECOLOGICAL ECONOMICS: A BETTER FRAMEWORK FOR SUSTAINABLE DEVELOPMENT

U.A.D.P. Gunawardena
Department of Forestry and Environmental Science,
University of Sri Jayewardenepura

Sustainable development has been the focus and the target of many resource management related issues. However, proper definitions and frameworks of action have seemed to be greatly unexplored. This paper aims at providing a framework for sustainable development based on concepts of ecological economics. The main focus will be on the issues of intra and inter generational equity on natural resource use and maintaining non-declining levels of critical natural capital.

The conventional economic view is generally optimistic about the ability of the economic system to overcome natural resource depletion with the help of the technological progress. However, conventional approaches in resource economics limit themselves to only optimal rate of exploitation of a natural resource and determination of optimal pollution discharges. Although such approaches are sensitive to scale issues at the micro level, it is insensitive to the macro level scale of the whole economy relative to the ecosystem. Although the market provides space for substituting abundant resources for scarce ones, it is not able to overcome entropy constraints. Such issues are not reflected in Pareto optimality since optimal allocation is independent of whether or not the scale of physical throughput is ecologically sustainable.

Therefore is important to recognize the existence of a new constraint on the physical scale of the economy relative to the ecosystem. This constraint has to be set according to the criteria of sustainability and under such constraint, the market will be able to achieve prices which reflect the social value of sustainability.

Unique natural environments and other critical natural capital need special considerations in economic analysis since technology can do little to replicate their ecological, physical and geographical characteristics. In order to determine the social cost and benefits of a decision to develop a previously undeveloped area, it is necessary to know both the preferences of present and future generations who may be affected by that decision. The existing valuation frameworks and discounting in cost benefit analysis have inherent biases against future generations. Recognition of such facts and identifying the means of minimizing such biases are essential in achieving sustainable development.

Ecological economic framework is essentially an extension of environment and resource economics in to the explicit analysis of biophysical constraints and equity among generations.

Forestry and Environment Symposium 2005, Sri Lanka: POTENTIAL OF AGROFORESTRY IN SUSTAINABLE DEVELOPMENT IN SRI LANKA

EXTENDED COST BENEFIT ANALYSIS OF SAMANALAWEWA HYDROELECTRIC PROJECT

E.P.N. Udaya Kumara & U.A.D.P. Gunawardena
Department of Forestry and Environmental Science,
University of Sri Jayewardenepura

The Samanalawewa Hydro Electric Project and its water commanding area is the subject of this study. This project is a single purpose hydropower project, which harnesses the waters of the Walawe Ganga by damming the river at the confluence of the Belihul Oya and Walawe Ganga at an elevation of 400m Mean Sea Level. The reservoir covers an extent of 897 ha at normal high water level and its catchment covers an area of 341.7 km.

As this was a single purpose project, much attention was not paid to other aspects such as supplying irrigation water for down stream, and other environmental impacts. Therefore this study sought to estimate the economic loss due to the reduction of land area and paddy yield at selected down stream areas, In ad;,li0on, it aims to estimate the economic value of lost carbon sequestration function of the Samanalawewa reservoir submerged area and to incorporate the above values in an extended Cost/Benefit analysis for the Samanalawewa project.

Primary and secondary data were used for this study, which involved a farm household survey. This research disclosed that the scarcity of water due to the dam has resulted in 11.64% of yield reduction (equivalent to 3ti944.38 bushels or Rs. 10.5 million) and 24.8)% of land become uncultivated (equivalent to 444.27 acres or Rs.11.7 million) annually. The global warming damage costs due to °he lost carbon sequestration function of the submerged area is estimated to be Rs. 0.22 million annually. The estimated economic value of surplus water in terms of foregone power generation from the leak at paddy harvesting periods (April, September and October) is Rs. 95.33 million.

LOCAL TOURISTS OF RUHUNA (YALA) NATIONAL PARK: ZONAL VISITATION, TRAVEL COST AND WILLINGNESS TO PAY

U. M. I. R. K. Weerasinghe, Dayananda Kariyawasam & Mangala De Zoysa
Faculty of Agriculture, University of Ruhuna

Ruhuna (Yala) National Park, a strict nature reserve which lies on the southern coast of Sri Lanka, covers 97,878 hectares of land. The park comprises of secondary forest where many species of mammals, avifauna, reptiles and birds are living in substantial numbers. The Park has achieved the international reputation. Evidently, all categories of some 100,000 tourists, 70 percent of which are local tourists visit the Park annually. Tourism in a sanctuary is both nature based and sustainable, and sustainability incorporates environmental, socio-cultural and economic dimensions. There should be a control of supply-oriented management securing the environmental and economic benefits. The public interest and enthusiasm in the Park could be used not only to market the product but also to conserve the resources. Hence, the study attempted to analyze the local demand of the tourists for Ruhuna National Park with the view of improving Ruhuna National Park as an attractive tourist's destination.

The local demand of the tourists for Ruhuna National Park is measured as zonal visitation rate, travel cost, and their willingness to pay. The highest visitation rate is recorded from Badulla (5.6) while the lowest rate is recorded from Matale (2.1). The visitors from Matale have the highest total travel cost (Rs. 732.50). Hambantota visitors spend Rs. 115.04 as the total travel cost. However, the multiple regression analysis shows that the visitation rate with income, age, educational level and 1oIa1 travel cost excluding the visitors from Matara and Hambantota districts, is highly correlated (r 2 = 0.935). However, the age is significantly correlated with visitation rate while total travel cost has a significant negative correlation with the visitation rate. According to the local visitors, the willingness to pay per person per year is calculated as Rs. 116.41.

THE LEVEL OF VARIATION IN YIELD AND YIELD DETERMINING FACTORS AND THEIR RELATIONSHIP IN DIFFERENT HEVEA GENOTYPES.

E.S. Munasinghe & A. Nugawela
Rubber Research Institute of Sri Lanka

Natural rubber produced by Hevea brasiliensis Muell. Arg. is an industrially important raw material for which demand continues both locally and internationally. It is produced from the latex extracted/tapped from the rubber tree.
In this study, variation in yield and some yield determining factors, i.e. girth, depth of tapping cut, tapping height and tapping angle and their relationships were studied on three genotypes (clones) of Hevea PB 217, RRIC 117 and RRIC 102. Clones have been planted in 1988 in a commercial estate in Sri Lanka and tapping began in 1994. From each clones, an area having ca. 100 trees was selected for the study.
Yield measured as latex volume was found to be highly significant clonal character. Among the three clones tested, the highest mean latex volume per tree per tapping was recorded in RRIC 102 whilst the lowest in PB 217.
Further, a significant tree-to-tree variation in yield within a clone was observed in all three clones. The maximum co-efficient of variation was found in PB 217 while minimum was in RRIC 102. Yield varied through different ranges in each of the three clones and PB 217 had more low yielding trees whilst RR1C 102 and 12It1C 117 had more medium yielding trees. Yield determining factors i.e. girth, depth of tapping cut found to vary within a clone in all three clones. Further, they were significantly and positively correlated to the yield. Tapping height and tapping angle also varied within a clone and they too contributed to the yield variation within a clone.
Out of the yield determining factors considered above, girth was the most important factor which governed the yield and it was further significantly and positively correlated to the depth of tapping cut.
It was clearly evident that yield determining factors used in the present study play a major role in determining rubber yield. Those arc mainly governed by the rootstock of the plant, environment conditions and agro management practices. Therefore by the adaptation of the correct agro management practices and technically correct tapping, such variations within clones can be minimized and it will enhance the existing productivity levels in Sri Lanka rubber plantations.

EXTRACTING VEGETATION INFORMATION FROM SATELLITE DATA FOR THE NILWALA CATCHMENT AREA, SOURTHERN SRI LANKA

S. Pathirana
School of Environmental Science & Management,
Southern Cross University, Lismore NSW 2450 – Australia

It is evident that increasing human activities on forest resources can lead to floods, soil erosion, loss of bio diversity, and increase in atmospheric gases causing global warming. Sustainable management of forest resources requires accurate data on the current status of tile environment as well as tools to support the decision making process. Remote Sensing and Geographical Information Systems have increasingly been used as decision support tools. Particularly, recent advancements in satellite remote sensing have facilitated acquiring valuable data and information in assessing (lie current status of the environment at varying levels of detail. The purpose of this study is to assess the potential of satellite remote sensing in vegetation mapping of the Nilwala catchments area of Southern Sri Lanka. The paper presents tile preliminary work amid at extracting vegetation information from Landsat TM and ETM data. The maps produced applying image processing techniques such as image differencing, Normalised Difference Vegetation Index (NDVI), ISOCLUSS unsupervised classification and Tasseled Cap Transformation show the extent, quality and change of vegetation in the catchments area. Information derived from satellite data can further be used in rnodeling erosion potential in agricultural areas, mapping the flood risk, and land cover and land use change analysis when combine with geographical information.

WATER SUPPLY PLANNING AND SIMULATION SOFTWARE PACKAGE - REALM

B.J.C. Perera
School of the Built Environment, Victoria University,
PO Box 14428 MCMC, Victoria 8001, Australia

REALM (REsource ALlocation Model) is a generalised computer simulation package that models harvesting and bulk distribution of -water resources within a water supply system. A wide range of operating rules can be modelled either directly or indirectly by exploiting the attributes of node and carrier types that arc!, used to configure the system. It uses a fast network linear programming algorithm to optimise the water allocation within the network during each simulation time step, in accordance with user-defined operating rules. REALM has strong water allocation capabilities but with limited water quality features. Nevertheless, these water quality-modelling capabilities are sufficient to model the water quality issues experienced in most urban water supply and irrigation systems. REALM has been developed and enhanced in response to user requirements and feedback from the users, and therefore has developed into a comprehensive tool far water supply planning and management. It has been used to model the planning and management of sustainable water systems, and environmental flow requirements. This paper describes the main features of REALM so that the potential users will have an appreciation of its capabilities. It also describes a case study dealing with main features.

GRANITE QUARRYING PROJECTS AND THEIR IMPACT ON THE ENVIRONMENT

K N J Katupotha
Department of Geography,
University of Sri Jayewardenepura

Surface and subsurface charnockitic gneissic boulders of the Kolonna Divisional Secretariat area have been separated and detached using bores and compressor machines to produce "blocks" for export. Four granite-quarrying projects were in operation at the Lanka-Beriya Estate, Bulutota Kadamuduna, near the Circuit Bungalow at Bulutota Kadamuduna and at Udahakanda village (Pitakanda). However quarrying in the above four sites has been abandoned stopped consequent to pressure brought by the public. Only one project is active at the Aigburth Estate in Suriyakanda to date.
This study aims at identifying the existing problems of the quarrying projects, examines how these quarrying projects can contribute to slope failure in the future; and makes recommendations as mitigatory measures for better understanding of uses and the management of resources. Accordingly, following conclusions can be made regarding the exploitation activities in the sites:
(a) local relief and other geographical parameters (physical and social) have not been given and concern prior to exploitation of the resources
(b) damaged and destroyed boulders and fragments have been dispersed and have dumped in the sites
(c) reserv4tions made by Ordinances and Laws for natural streams (Poddana, Bulutota and Ittakanda GNDs), electrical transmission lines and cemeteries (Ittakanda GND) have been ignored during these exploration
(d) after removal of boulders, pits burrows have not been filled properly with compacted earth
(e) trees and vegetative species have been destroyed and growth retarded due to operations carried out (Bulutota Kadamuduna, Aigbirth Estate and Udahakanda village
(f) vibration during drilling and dynamiting (dynamiting is not presently used) have created surface cracks in the area immediately behind the boulders
(g) dust from drilling operations are removed by wind and create environmental and health hazards
(h) development of gullies and surface erosion is caused by heavy rains after blocks are removed; and
(i) closed pits as well as the open pits of the area are able to create gullies by surface erosion and can store an extensive volume of water increasing sub-surface erosion It is evident from detailed field inspections and slope analysis around the sites that illegal and unmethodical quarrying of these boulders in whatever form contributes to slope failure and exerts a negative impact on the environment. The threats to human life and property as well as the degradation of the environment has contributed to a strong opposition by the public to the operation of quarries.

ENVIRONMENTAL DEGRADATION DUE TO INLAND CORAL MINING IN AKURALA, SOUTHWESTERN COASTAL ZONE

M.M.R.K. Jayarathne & S.N. Wickramarathne
Departmert of Geography,
University of Peradeniya

The Akurala coastal stretch (approx. 87-.90 km from Colombo) provides an excellent example of environmental degradation due to human exploitation of coastal resources. Holocene corals are found 2.5 - 3.0 m below, the surface in a stretch extending about 1 km inland from the coast. The objectives of the present study were to assess the degree of environmental degradation resulting from inland coral mining in this stretch. It was based on a field survey, air photo interpretation and GIS application.

Although inland coral mining in Akurala records a history of over two hundred years, this activity has intensified over the past fifty years. The remaining pits vary in size (small: 10­ - 465 m2, medium: 465 -1365 m2 and large: 1 365-929 (1m2). Mangrove plants and mangrove associates invade these pits. The commonest are Acrosticum aureum, Bruguiera sexangula and Lumnitzera racemosa. Among the mangrove associates and non-mangrove species are, Cerbera mangas, Hibiscus tiliaceus, Pandanus sp. Premna servatifolia and several sedge species (Cyperaceae). There are also such invasive plants as Annona glabra, Salvinia molesta, and panicu.s maximum growing in and around the pits.

The buried coral beds are a valuable resource providing employment in mining and associated activities to 45% of the area's population. Yet, coral mining has created many problems. The threats of deep pits to people, land subsidence and damages to houses are the main problems. Proliferation of invasive plants and mosquito breeding destroy the aesthetic value.

Among the recommendations emanating from the study, the closing of abandoned pits is most relevant. Also aquaculture in large pits can be viable. Planting mangroves in some parts too can help restore Sri Lanka's dwindling mangroves.

CONSERVATION OF HISTORICAL RESIDENTIAL BUILDINGS IN URBAN SETTINGS

Janakie Edirisinghe 1 & Malik Ranasinghe 2
1Department of Estate Mgt. and Valuation,
University of Sri Jayewardenepura
2 Faculty of Engineering, University of Moratuwa

Historical areas and built heritage are important elements which contribute to create image and identity of a city. Its creativity and diversity are evidence of human progress and essential factor in development. Residential properties constitute a considerable portion of the built heritage and it is the major land use in a city's functional structure.

The characteristics such as architectural features, internal design, materials used for construction of houses enrich our knowledge and understanding of the way we used to live. Those historical structures give pleasure to people, form a valuable economic, social and educational resource. They are also legacies of our past.

Many residential properties of important historical value in urban settings are confronted with a situation where they are either neglected or destroyed due to various reasons. The values inherent in such properties are rarely recognized and appreciated. The issues and difficulties in conservation and management of old residential buildings in the context of urban development are analyzed and discussed in this paper.

COMPARISON OF TOP HEIGHT AND DOMINANT HEIGHT WITH TREE VARIABLES AT THE EVEN AGED Pinus caribaea (MORELET) PLANTATION AT YAGIRALA

Kandasami Pirapaharan & S.M.C.U.P.Subasinghe
Department of Forestry and Environment Science
University of Sri Jayewardenepura

Top height and dominant heights are confusedly interpret in many countries. The main aim of this study was find the similarity of above two terms and to build some models to predict them.

The study was carried out in Yagirala 25 year old even aged Pinus caribaea plantation. Top height and dominant heights were compared with other tree variables. Stratified random sampling without replacement was used to select the sampling unit. Circular plots of 0.05 hectare with slope correction and boundary adjustment were used to obtain the required tree measurements.

Diameter at breast height, total height, lower and upper crown height were measured and basal area and crown depth were calculated. Top height and dominant height were also estimated.

Results indicated that there is a significant difference between top and dominant heights. Also two separate equations to predict these two heights were developed. According to the results initially ten equations were selected. Five equations described the relationship between top and total height while the o1her five described the relationship between dominant height and total height. Finally the best two equations were selected using coefficient of variation values and the distributions of standard residuals.

COMPARISON OF TOP HEIGHT AND DOMINANT HEIGHT WITH TREE VARIABLES AT THE EVEN AGED Pinus caribaea (MORELET) PLANTATION AT YAGIRALA

Kandasami Pirapaharan & S.M.C.U.P.Subasinghe
Department of Forestry and Environment Science
University of Sri Jayewardenepura

Top height and dominant heights are confusedly interpret in many countries. The main aim of this study was find the similarity of above two terms and to build some models to predict them.

The study was carried out in Yagirala 25 year old even aged Pinus caribaea plantation. Top height and dominant heights were compared with other tree variables. Stratified random sampling without replacement was used to select the sampling unit. Circular plots of 0.05 hectare with slope correction and boundary adjustment were used to obtain the required tree measurements.

Diameter at breast height, total height, lower and upper crown height were measured and basal area and crown depth were calculated. Top height and dominant height were also estimated.

Results indicated that there is a significant difference between top and dominant heights. Also two separate equations to predict these two heights were developed. According to the results initially ten equations were selected. Five equations described the relationship between top and total height while the o1her five described the relationship between dominant height and total height. Finally the best two equations were selected using coefficient of variation values and the distributions of standard residuals.

SURVEY OF THE PRESENT STATUS OF STREET TREE PLSNTING IN

S. Sornalingam1 & D. M. S. H. K. Ranasinghe2
1Ministry of Irrigation & Water Management
2Department of Forestry and Environmental Science,
University of Sri Jayewardenepura

Urban Forestry embraces parks, avenue planting or street trees, boulevards, cemeteries, parking places etc. It plays an important role by providing aesthetic beauty and environmental pollution by absorbing vehicular emission. Colombo, which is the commercial capital of Sri Lanka, is plagued with high population density and high commercial activities. Urban forestry has a significant potential in improving aesthetic & environmental aspects of the city.
Objectives of this research project were to identify the existing situation of the street tree planting in the 15 sub divisions of the Colombo Municipal Council Area and to give some recommendations for improvements. 2 trunk roads were selected per division randomly and the status of trees in these roads was recorded. Measurements of crown size, height, diameter at breast height, height of the first branching, widths of roads, sidewalks, and center medians were measured and recorded. Observations done in status of maturity, pest disease attack, root pattern, foliage characteristics such as whether easily decayable or moderately decayable and small or large leaves, land use patterns such as commercial, service & administration, residential and recreational land use & recorded.

According to the results, a difference in the status of street trees in the 15 sub divisions in the Colombo Municipal Council Area was identified. The sub divisions can be ranked according to the total crown area per kilometer as follows: sub divisions 7, 14, 3, 11, I, 2, 5, 10, G, 13, 12, 15, 8, 9 & 4. The sub divisions can be ranked according to the number of trees per kilometer as follows: sub divisions 7,10,14,1,13,2,5,6,12,11,3,15,8,9 & 4. The sub divisions can be ranked according to the number of species diversity per kilometer as follows: sub divisions 7,13,12,14,1,S,a,:;1,15,8,10,6,3,4 and 9. Terminalia Catappa (Kottang), Polyalthya longifolia (Willow): Samanea Saman (paramara), Delonix regia (Maimara), Casia fistula (Ehala) & Plumeriya spp. ( Araliya) represent 5 or more than 5 % in the sample survey. 56 tree species were identified in the study area.
Out of 30 selected street sites, 7 were identified as sites, which need immediate planting programs and another 17 sites needs planting program. 9 street sites need immediate pruning operations as they have trees with first branching height of less than 2.00 meters, which may interrupt the traffic flow. 6 street sites were identified as sites, which need immediate removal and replacement operations as they have over-matured trees, which may become hazardous trees if necessary actions are not taken. Out of 15 sub divisions surveyed, 7 were identified as affected with pest-disease attack. Further, some recommendations are identified as to improve the existing situation of' the street tree planting in the study area and a draft action plan for 5 years was drawn. Further scientific studies such as species, which can reduce soil erosion, pollutants absorbers, etc. are needed for better management of urban trees.

VARIATION OF SPECIFIC GRAVITY WITHIN Eucalyptus grandis TREES GROWING IN DIFFERENT SITE CLASSES.

N.D. Ruwanpathirana 1, H.S. Arnarasekara2 & M.P. De Silva3
1State Timber Corporation, Sampathpaya, Battaramulla
2 Department of Forestry & Environmental Science,
University of Sri Jayewardenepura
3Faculty of Science, .University of Ruhuna

Wood is a very remarkable material with variability and flexibility. The variability of wood increases its utility. It may be also a major drawback to its efficient use as raw material. Therefore understanding of pattern of wood properties within the tree has become important. In addition, growth rate and its v1fect on wood properties are of practical importance to maximize wood and fiber prcoc3~nction. In this study, variations of specific gravity within the trees of 30-years old Eucalyptus grandis extracted from Pattipola, Santhipura and Piduruthalagala in Nuwara-Eliya districts were studied. Data were collected in relation to site class (growth rate) as determined by tree height. The objective of the study was to find out whether specific ; gravity is affected by growth rate of tree. Specific gravity values were collected in a systematic manner, which are essential in commercial utilization of this species. Three sites, namely Slow Growth Site (SGS), Medium Growth Site (MGS) Fast Growth Sit; (FGS) were chosen. Five trees from each site were taken for the investigation. Tree height difference between SGS (33.8 meters ) FGS (45 meters) was significantly different (P_<0.05) but not between SGS and MGS (38.7 meters).

Variation patterns of specific gravity in radial direction were studied using two linear sections extracted across the diameter of every sample disc, from north to south and cast to west at different height levels at breast height a !ad at 20%, 40%, 60%a and 80'% of total tree height. 3021 wood samples of 2*2*1 cm dimensions were used for specific gravity determination.

In general, low specific gravity values were observed at pith in all three sites. In fast growth site, specific gravity increased from pith; thereafter it remained constant towards the bark with small fluctuation. In slow and medium growth sites, however specific gravity increased gradually towards the bark. Fast Growth site maintained the highest specific gravity values throughout piths to bark. The specific gravity of SGS and MGS increased rapidly with increasing distance from pith.

In general, specific gravity increased with tree height in all sites except at 20% height level in SGS and MGS. Mean specific gravity values in SGS at breast height, 20%, 40'%, 60% and 80% height levels were 0.432, 0.431, 0 433, 0.468 and 0.475 respectively. Specific gravity values for these levels in MGS were 0.4,41, 0.435, 0.467, 0.477,0.542 and Specific gravity values were 0.479, 0.482, 0.493, 0.525, 0.553 for FGS respectively.