Wednesday, October 11, 2006

Community-Based Innovations In Reforesting The Sri Lankas Landscape: The Context Of Sustainable Resource Management

A. Wickramasinghe
Department of Geography
University of Peradeniya

The recent emphasis on community-based innovations is strong and often points to the fact that such systems have been feasible over generations and have resulted in hundreds of spatially varying agro forestry systems. The conversion of land deforested land into a production systems which is rich in diversity both in terms of species composition and structure is difficult, costly and not promising if it is to be done by external agencies. This paper brings out the socio-cultural context within which indigenous systems have evolved, replicated and sustained over generations and across space, with reference to the examples drawn from the central highlands in particular. This paper focuses on the unique system of the 'Kandyan home garden that has not only been central to discussion in many forums but has been recognized and merited as a community based system, which has created an 'oasis of biodiversity, in the landscape.

The example drawn from Sri lanka show two important features of policy implications. The first is related to the process, which intimately evolves from individual households, with their input. and then spread across creating community-based mosaics of forest in the landscape. The community explained in this paper emerges in the geographical space m association with human habitation, social process. indigenous knowledge and practices of resources of management. The second feature is associated with the mechanism; the mechanism of learning und replication which symbolically present the essence of community Innovations in reforesting the landscape and managing the resources for sustainable survival.

The strategic implications of the results are many; they urge us to have a new paradigm of forestry in Sri Lanka. where future requirements are to be satisfied through a facilitation process, which will deteriorate the essence of 'community-based innovations'. A further need here is to eliminate the using of local communities as instruments or vehicles to execute the externally defined programmes, and promote community-based practices.

Peoples Participation In Forest Resources Development: A Case Study In Polpithigama, Kurunegala

H.G. Gunawardane
Forest Department

This paper illustrates the results of ,.r study carried out by the Forest Department aimed at re­establishment of vegetation covers on state owned barren lands as well as under-developed private land through people's participation. The study area was at Polpithigama, in Kurunegala District situated adjacent to Pallekele Forest Reserve (11,000 hectare) in Kurunegala and Anuradhapura Districts. The settlers of Polpithigarna are second and third generation families migrated from neighboring villages within last 2-3 decades. Eighty seven percent of villages were subsistence farmers. The majority belongs to under privileged state of the society. Except the Funeral Aid Society. there were no other social organizations.

The management interventions of the Extension unit of the divisional forest office in Kurunegala included formation of' farmers organizations, block planting, homestead development and nursery establishment.

Block planting, homestead development and nursery management were major activities carried out under this trial. Out of 127 farmers 76 participated in this programme and 38 hectare of land was planted with Acasia oriculiformis. Sixty one (61%) percent of blocks were successfully intercropped with vegetables, pulses and other short term crops. Total seedling requirement (150,000) was provided by the village nursery maintained by farmer society. Land clearing, soil preparation, planting and other all activities were carried out by the participation of the farmers and their families. Maintenance and protection were done by farmers. It was observed that the average income of farmer has increased by 37% during the first year and by 22% and 17% during second and third years respectively. Sixty eight percent of the farmers had developed their homesteads very satisfactorily. The observations have revealed that, vegetation cover and soil fertility has improved and soil erosion is under control. Micro-climate of the area also has changed desirably.

According to the estimates, Forest Department's contribution m the programme was Rs. 294,000.00. Participants contribution was Rs.716,782.00 which included establishment and maintenance costs for 3 years. Therefore this study clearly disclosed that if the proper extension programmes were conducted and farmers were motivated, it is possible to seek active participation of farmers for development of forest resource.

Tuesday, October 10, 2006

Comparative Study On Recommended Dietary Allowances And Real Dietary Intake Of Some Sri Lankan Households

V.J. Jayasinghe, AM. Muhuris and A. Bamunuarachchi
1National Hospital of Sri Lanka
3Department Chemistry, University of Sri Jayewardenepura

This project was carried out to compare the real dietary intake of the people living in the village of Raigama in the Kalutara district (Site A) and Poddala in the Galle district (Site B). The study was carried out by obtaining information on a pre-prepared questionnaire. The information included the socio economic status, health status in the families investigated and also the amount of various daily dietary intake components. The latter data was then converted into calories, vitamins, minerals etc. using the national food composition tables.

The mean dietary intake of food items reflected an over dependence on Rice in site A and Bread m site B. The daily consumption in both sites was very high and over 90% of the population in site A consume protein even over 200% of recommended dietary allowances.

The intake of Energy, Vitamin A and Riboflavin in site A is not satisfactory while energy. Vitamin A. Iron, Riboflavin and Niacin in site B are not satisfactory in relation to the standards.

The analysis of Body Mass Index (BMI) shows that the percentage of obese males in site B was greater than site B while the normal and under weight percentages of both sites were more or less the same. The obese percentage of females in site B was three times higher than the site A. Seventy percent of females in site A were able to maintain normal body weight while m site B 40% did so.

Agro forestry Systems Of The Tea Smallholdings In Matara District: Selection Of Trees And Economic Viability

L.M. Abeywickrama, R.A.G. Senaratne and M.De Zoysa
Department of Agricultural Economics, Faculty of Agriculture, University of Ruhuna

The tea sector in Matara district is dominated by small-scale holdings as monoculture and mixed gardens. High shade trees consisting of forest trees and perennial crops have been an integral component in tea lands which is analogous to natural forest conditions. Recently, with the rapid increase of demand for timber, there is an increasing trend to remove high shade trees neglecting the sustainable agro-forestry system in tea small holdings.

The study attempted to asses growers' interests. agronomic problems and financial benefits of managing high shade trees in tea small holdings. Findings are mainly based on data gathered from 200 indiscriminately selected small scale (< 1 ha.) tree growers in Matara district by administering a questionnaire based interviews. Direct observations were also made to assess the canopy of high shade trees, tea cultivations and cultivated lands. Prices of timber and marketing process of timber were gathered using participatory approaches.

Study reveals that coconut, jak, mahogay. arecanut and lunumidella are the dominant high shade tree species in tea small holdings less than 0.25 ha. while albizia dominates in the holdings larger than 0.5 ha. Thirty three percent of the growers are not interested in planting new high shade tree species in then- holdings except coconut and fruit trees due to prevailing Market imperfections resulting from existing timber trade policies. Profit margins of timber trade earned by merchants are very large compared to the low revenues received by the growers due to lack of clear tittles for many lands and lack of market information. Discounted financial value of' land equivalency ratio (LER) is higher for tea small holdings with albizia trees compared to other tea based agro forestry systems.

Critical assessments and restructuring of policy related to land tittles, subsidy schemes for tea cultivation, high shade tree replanting programs, and timber trade have become important issues to sustain the agro-forestry system in tea small holdings.

Seedling Survival And Growth Of Mesua And Dipterocarpus Species In A Sri Lankan Rain Forest

B. M. P. Singhakumara and P. M. S. Ashton
1Department of Forestry and Environmental Science, University of Sri Jayewardenepura.
2School of Forestry and Environmental Studies, Yale University New Haven, USA.

Seedlings of Dipterocarpus (D. hispidus and D. zeylanicus) and Mesua (M. ferrea and M. nagassarium) were investigated for their survival and growth in different microenvironments in a lowland rain forest in south-west of Sri Lanka. These species occur together as canopy dominants of late-successional rain forest. Partitioning of the regeneration niche can be one explanation for the co-existence of ecologically similar canopy tree species within a forest. This study tested that differences in disturbances across the topography of lowland rain forest cause different survival and growth rates in closely related tree species among and within canopy openings of different size.

Seedlings were planted in plots located in five zones representing a range of forest around storey micro-environments found adjacent to and across canopy openings of three sites- valley, mid slope and ridge top. Plots were located from north to south across each gap (i) under storey 10 m to the south of the gap, (ii) southern gap edge, (iii) centre, (iv) northern edge and (v) under storey 10 m to the north of the gap. Experiments were designed to monitor survival and growth of planted seedlings for two years. At the end of two years survival was calculated, height increment recorded and destructive samples were taken to measure dry mass gain of root, stem and leaves.

Seedlings of Mesua ferrea, M. nagassarium and D. zeylanicus showed high survival on all sites and in all gap/ canopy conditions. D. hispidus showed the lowest survival in all sites. Growth measures attained maxima in the centre gap/ canopy condition in the three sites for all species. Results also demonstrated clear differences among species. Dipterocarpus exhibited greater growth responsiveness than Mesua species. These differences appeared to be related to availability of soil moisture and ground storey radiation regimes. This study demonstrated that closely related species have specific growth characteristics that allow each to establish and grow better than its relatives in particular forest microenvironments.

Study Of High Shade (Gravillea robusta) On Micro Climate Of A Tea Field

Ediriweera E.P.S.K.1 Anandacoomaraswamy A.2
1Department of Forestry & Environmental Science, University of Sri Jayewardenepura, Nugegoda.
2Division of Plant Physiology, Tea Research Institute, Talawakelle

Shade trees are widely grown in tea plantations in Sri Lanka to provide physical shade for tea during the dry weather. It also enriches the soil fertility by lea! fall. An investigation was carried out to quantify the radiation and canopy temperature around an eight year old 'high' shade tree Gravillea robusta. The measurements were made at hourly intervals from 9.15 am to 3.15 pm on January 13th, 1999. In addition, relative humidity was measured in the shaded and unshaded area.

The radiation was measured by a tube solarimeter and the canopy temperature was measured by infra red thermometer. The organic carbon content of the topsoil between two shade trees were measured at north-south and east-west directions at 2m intervals.

On a clear day the shaded area ranged from 12-15%, highest during the early morning and lowest during the noon. The canopy temperature under shade was 4-6°C less than the unshaded area. There was a marginal difference in relative humidity between shaded and unshaded area. The relative humidity of the shaded area was marginally higher than the unshaded area in the afternoon. The organic carbon content ranged from 3-4%. A high value was found near the base of the tree and a low value was found midway in between the shade trees. The mean leaf area index of the Gravillea canopy was 6.9 and the canopy extinction coefficient was 0.21.

Growth And Biomass Accumulation Of Some Early Successional Woody Species In An Uprooted Rubber Field At Kamburupitiya

H. K. P. Jayasekera and R. Senaratne
Department of Crop Science, Faculty of Agriculture,
University of Ruhuna, Mapalana Kamburupitiya.

A study was conducted on a successional vegetation in an abandoned uprooted rubber field at Kamburupitiya in 1999. It involved determination of growth parameters such as height, girth, biomass accumulation and partitioning of dry matter in three most widely occurring early successional woody species, namely Macaranga peltata, Alstonia scholaris and Trema orientalis of varying ages (3. 5 and 7 years). Here three trees of each species were sampled except A. scholaris where only 3 and 5 year old trees were sampled for each age class from each succeessional stand.

Growth parameters (height, gbh and rate of height and diameter), growth of all three species at 3, 5 and 7 years and the partitioning of dry matter to the leaves were compared among the three tree species and the ages sampled. According to the results obtained A. scholaris showed the highest absolute and relative stem elongation followed by M. peltata and then T. orientalis. However it recorded the lowest rate of increment in girth. At three years of age more dry matter is being partitioned to leaves and as the age progressed this proportion is significantly reduced in all the tree species sampled.

The implications of inter-specific variations in growth attributes and accumulation and partition of dry matter on nutrient conservation and restoration of disturbed agro-ecosystems are discussed.

Successional Developments In Some Human Impacted Areas Of Kamburupitiya Following The Nilwala Project

K. K. L. U. Aruna Kumara and R. Senaratne
Department of Crop Science, Faculty of Agriculture,
University of Ruhuna, Mapalana, Kamburupitiya.

A study on successional development at a human-impacted site was conducted at Kamburupitiya from June to October 1999. This site was previously maintained under agroforestry, but has been severely disturbed and its soil has been removed down to the bedrock in 1987, under the Nilwala project. Three such sites (12 X 104, 2 X 104, 1 X 104 m2) which are about 500 meters apart were selected for the study. The study involved characterization of the physical and chemical properties of the soil and assessment of successional development. An undisturbed site was used as the control experiment.

Bulk density, true density and porosity of the soil were 1.163 gcm-3, 2.14 gcm-3, and 45.6 gcm-3. respectively, with a water holding capacity of 28.5%. The per cent of organic matter and N in the soil were 0.451 and 0.0088, respectively, whereas the corresponding values for the undisturbed site, were 1.214 and 0.095. The cation exchange capacity of the derelict sites was 4.71 m.e. per 100g of soil and had a pH value of 4.2. The corresponding figures for the reference site were 7.40 and 5.43, respectively. Plant populations in three sites were 15,902, 21,266 and 98,776 ha-1. Even alter 12 years, only about 0.13-0.26% of plants had a girth exceeding 3 cm at breast height and only about 1 % of plants had a height greater than lm. Twenty one species occurred in three sites, which belonged to sixteen families, namely (in order of abundance), Graminae, Gleicheriaceae, Apocynaceae, Leguminosae, Verbanaceae, Rubiaceae, Burseraceae, Cyperaceae, Compositae, Malvaceae, Lauraceae, Periplocaceae, Melastomataceae, Euphobiaceae, Anacardiaccae and Rhizophoraceae. Of these species, about 75% were herbaceous while the rest were woody. Alstonia scholaris was by far the most abundant and dominant woody species followed by Cinnamon verum, Carallict brachita. Even after 12 years of the disturbance, the biomass production of Alstonia scholaris was only 9.5 gm-2 or 95 kha-1, showing an extremely successional development. Ecological implications of such a tardy successional development and human interventions required to facilitate and catalyse the natural successional processes are discussed.

The Variation In Leaf Structure Of Seedlings In The Families Dipterocarpaceae, Clusiaceae And Myrtaceae Under Different Light Environments

B.M.P. Singhakumara1, H.K. Gamage1 and P.M.S. Ashton2
1Department of Forestry and Environmental Science, University of Sri Jayewardenepura, Nugegoda.
2School of Forestry and Environmental Studies, Yale University, New Haven, USA.

Light has been characterized as the most important environmental factor that affect the leaf structure of tree seedlings in tropical rain forest in South and Southeast Asia. Many studies have been carried out on leaf structure of early-successional and late-successional species and also among the species within the same successional status. These studies have helped in creating a clear understanding of ecological distribution in relation to each species. The present study examined the Icaf structure of six canopy tree species that are considered to be relatively shade tolerant in lowland rain forests in Sri Lanka.

Seedlings of Dipterocarpus zeylanicus, D. hispidus (Dipterocarpaceae), Mesua ferrea, M. nagassarium (Clusiaceae), Syzigium firmum and S. rubicundum (Myrtaceae) were grown in different controlled environmental shelters that simulated a range of light environments found in the ground storey of the rain forest. Two treatments exposed seedlings to different duration of full sunlight. These simulated the ground storey Photosynthetic Photon Flux Density (PFD) that were comparable to the centres of about 200 m2 and 400 m2 canopy openings. Three other shelters exposed seedlings to uniform diffuse light conditions that simulated amounts and qualities of radiation similar to that of the forest understorey (PFD 50, R:FR ratio 0.46; PFD 350, R:FR ratio 0.97; PFD 800, R:FR ratio 1.05). A control light treatment proved full sun light quality (PPFD 2000, R:FR ratio 1.27) for the seedling growth.

The attributes measured were thickness of leaf blade, upper and lower epidermis, palisade mesophyll and number of layers, and stomatal frequency. Results show that Syzygium species have highest in leaf blade, palisade cell thickness and stomatal frequency followed in order by Mesua>Dipterocarpus. This suggests that Syzigium species are more light tolerant but less in drought tolerance. The thickest upper and lower epidermis in Dipterncar/n4s reveal that they are more efficient in water use. Syzigium and Dipterocarpus exhibit rows in palisidae mesophyll when exposed to full sun. These findings elucidate some of the relationships between leaf anatomy and the species ecology across the forest topography.

The Development Of An Air-Emission Inventory And Its Benefits

S. R. Jasinghe and A. A P. De Alwis
1Air Quality Division, National Building Research organization
2Department of Chemistry and Process Engineering, University of Moratuwa

An air emission inventory is an essential planning tool in environmental management of the air shed. Today the state of the city's and suburbs air shed is fast becoming unsatisfactory and a recent fundamental rights case initiated by a Non-governmental organization to draw the attention to this fact Succeeded and has forced the authorities to accelerate implementing guidelines and practical steps in a short time span. When reviewing standards it is seen that we established certain standards in cases even below the suggested WHO guidelines and implemented precious little in a technical way thus leading, to the gradual deterioration of the air shed over a period of time.

In all these evaluations an air emission inventory is quite useful as a development planning tool. At present Sri Lanka does not have such an inventory for any region or locality and the steps taken to develop an inventory for the Sapugaskanda area an area of high industrialization is discussed in this paper. Both stationary and mobile sources are considered. Some air pollution assessment modeling was done to develop data and these have also been validated from the monitoring data available.

The need for an Air Quality Index (AQI) is also stressed as this is also a missing element in the present management system. A suggested scheme is given and some data is analyzed for the indication of air shed quality.

Waste Human Hair-An Oil Recovery Material Par Excellence!Waste Human Hair-An Oil Recovery Material Par Excellence!

M.M. Samoon1 and A.A.P. De Alwis2
1Post Graduate Institute of Science, University of Peradeniya
2Department of Chemical Engineering, University of Moratuwa.

The problem of oil pollution is today becoming a topical issue with two recent incidents at Colombo harbor (due to a breakdown of a CPC pipe line) and at Kirinda (due to a breakdown of a salvaging operation of a ship). These incidents sometimes cause too much reaction in some quarters. However, pollution from this source is not a new phenomena as service stations scattered all over the island release oil to surface waters, drains or land. Some of these discharges also find their way into the sea via river outfalls. Most importantly a majority of the service stations are closer to the coast as much of the economics in Sri Lanka are confined to the coastal belt. What has been realized is that in Sri Lanka yet the capability does not exist to handle a problem of this nature in an effective manner. It is also felt that there is an urgent need for a mechanism to take effective action in an event of this nature.

The study concentrates on an observation made in the United States by a hairdresser in the state of Alabama, which, was reported as a short piece of news in a US trade journal. The affinity of oil to human hair has been found to be high and this observation is subjected to some theoretical and experimental study. Results from the practical findings are presented here. It is shown that there are many ways of utilizing this affinity in oil pollution control. There is potential to utilize the characteristics in a skimming device or as an adsorption system. It is found that human hair adsorbs, rather than absorbs, oil which means that instead of bonding with the hair, the oil is retained in layers on the surface of the hair stands. Few types of devices have been constructed and tested and the results are quite positive and encouraging.

As the method involves removal and recovery of oil, the potential exists in this way for oil recovery and reuse which is quite advantageous.

Environmental Impacts of The Proposed Baddegedara Impounding Reservoir

N. Ratnayake and P.Y.D. De Silva
Department of Civil Engineering,
University of Moratuwa.

The alternative sources of water available for the consumers in the project area covering Talpe, Habaraduwa, Koggala EPZ and coastal belt, Ahangama, Dikkumbura and Imaduwa are ground water, or surface water from Gin ganga, Nilwala ganga or the proposed impounding at Baddegedara.

The first choice on the basis of water quality and treatment costs was ground water, but after a test drilling program this source was found to be inadequate.

The proposed impounding reservoir at Baddegedara is located near to the project area and technical feasibility studies revealed that this is a feasible proposal.

Positive and negative environmental impacts of the proposed project were identified using an environmental interaction matrix and it was attempted to evaluate the overall impact using the Battelle's Environmental Evaluation System. Weights for the different impacts were assigned depending on the relative importance of the impacts. Value functions for some of the impacts were developed.

The topography of the area does not lend itself to the fashioning of a deep lake. According to past studies, it has been showed that the ideal wild life lake is shallow with gently sloping shores. This type of situation could he expected from the proposed impoundment. These natural qualities of the habitat could be further augmented by various management techniques such as the restriction of the area of impoundment and catchment.

Measures To Reduce Environmental Impacts Of Gem Mining

D. K. N. G. Pushpakumara1 and H. C. Panditharathna2
1Department of Crop Science, Faculty of Agriculture,
University of Peradeniya.
University of Peradeniya.
2Sampath Bank, Avissawella.

Sri Lanka has reasonable endowments of mineral resources in relation to its size. Gems have been the most economically valuable resource accounting for more than 90% of all mineral exports in the country. Despite the relatively high economic and social benefits gem mining cause significant environment damages.

A field survey was conducted using a semi-structured questionnaire in selected assistant "government agent divisions of Rathnapura district during the period August 1998 to November 1998 to identify the environmental damages and possible practical measures to minimise such problems. Discussions were held with officers involved in the gem mining industry and miners under different mining categories. Wherever possible, information was also collected from direct observation and field surveys.

Results of the study revealed that several environmental impacts are obvious in the Rathnapura district due to gem mining namely, natural soil erosion, sedimentation, water pollution. removal of vegetation cover, flooding, landslides, ground water depletion, risk and/or damage to wild life, reduction of irrigation efficiency, health problems such as malaria, reduction of potential of agricultural lands and other damages including cracking walls of houses and man made structures. Results also indicated that small and large scale illegal mining is fairly widespread even in rivers despite regulatory measures. License holders usually neglect the license rules to get high profit. Supervision of mining activities is very low due to corruption in low enforcement agencies and lack of officers.

Modern techniques should be used in gem prospecting, fines and security deposits should be effectively used to rehabilitate abandoned gem pits, issue of licenses to defaulters should be avoided, license should be issued as early as possible before wasteful methods are employed by illegal gem miners, digging too many pits in one place should be prohibited, proper management and monitoring must be maintained through careful planning, and participation of the local community to pressurise all gem miners to minimise environmental damages have been suggested as remedial measures.

Association Between ambient air pollution and acute child - Hood Wheezy Episodes In Colombo

*M.P Sumanasena, R. P. Samarakkody, S. R. Jasinghe, A. P Hettiarachi
*S.P. Sumanasena, *J Kudalugodaarachchi.
Joint Study by the Environmental Division, National Building Research Organization and the *Faculty of Medicine, University of Colombo.

This study analyses the air pollution data from the continuous, fully automated, ambient air quality monitoring station operated at Colombo Fort and the records of daily attendance, at the Colombo Lady Ridgeway Children Hospital (LRH). for episodes of severe wheezing which required nebulizer therapy as an immediate treatment over a period of one year from 1st July 98 to 30th June 99.

Daily maximum one-hour averages of Sulphur Dioxide (SO2) and Oxides of Nitrogen (NOx) have been used as the indicator parameters for air pollution. It was observed that the changing pattern of both pollutants is consistent (r > 0.6) throughout the period of the study.
It was also observed that the incidence of the daily nebulization rate and daily maximum one-hour ambient sulphur dioxide and oxides of nitrogen were normally distributed over the study period.

In this study, the date of occurrence of the maximum and the minimum air pollution levels derived from daily maxima of Sulphur Dioxide (SO2) and Oxides of Nitrogen (NOx) in each week (from Sunday to Saturday) were compared with those of daily attendance with acute wheezing at the LRH.

Out of fifty one (51) weeks, the occurrence of' the highest nebulization at the highest polluted day (with respect to sulphur dioxide and oxides of nitrogen) and the lowest nebulization at the lowest polluted day in each week throughout the year was highly significant (binomial test, p=0.05).

This study clearly indicates that there is a strong association between ambient air pollution (with respect to Sulphur Dioxide and Oxides of Nitrogen) and acute child hood wheezing episodes, in Colombo.

Use of seeds of Moringa oleifera and wood of phyllanthus emblica to clarify turbid waters and wastewaters

M. A. A.W. Moramudali, P. Fernando, P. A. J. Yapa
Department of Botany
University of Sri Jayewardenepura

Ability of mature and immature seeds of Moringa oleifera and wood of Phyllanthus emblica to purify turbid waters and wastewaters was investigated.

Mature seed extracts of Moringa were comparatively more effective than immature seed extracts in purifying turbid waters. Mature seed powder at 50 mg/20 ml reduced the turbidity (NTU) by 95% within 2 hours. It was the aqueous extract of Moringa seeds that was effective in clarifying turbid waters, not the insoluble fraction. These observations are complementary to results of some previous workers. A positive relationship between protein content and purifying ability of seed extract was also observed.

It was also found that extract of mature Moringa seeds have an ability to clarify textile dye solutions. All four solutions of textile dye namely Terasil Blue 3RL-02, Terasil Navy GRL­C, Terasil-Red R and Terasil Yellow 4G were clarified by Moringa seed extracts.

Studies on pH and the conductivity of different types of water samples showed that pH is slightly reduced and conductivity is rapidly increased when the sample were treated with Moringa seeds. In addition, the conductivity was found to fluctuate temperature of treated samples.

The effectiveness of the mature seeds of Moringa against the bacterial growth of polluted waters was also studied. It was found that there is a significant difference between the bacterial growth of treated and untreated samples. It was the quantity of seeds used that mostly affected the bacterial growth, than the time exposed to the seeds.

Antimicrobial activity of crude aqueous extract of Moringa seeds were studied against E. coli and Proteus sp., which are indicative of faecally polluted water and disease causal organisms. Clear inhibition zones were observed for both organisms.

The purifying ability of dried fruit, dried and non-dried branches of P. emblica was also investigated. The dried branches of P. emblica were found to be more effective in purifying turbid water whereas the non-dried branches showed little effect. Dried fruit did not show any effect.

The purifying ability of seeds of M. oleifera and various parts of P. emblica plant was also investigated against paper factory effluent but no significant effect was observed.

Emission Control Strategy For Sri Lanka By Improving Vehicle Inspection & Maintenance Activities

K.M. Karunathilake1 and J.M.S.J. Bandara2
1Industrial Development Board of Sri Lanka
2Department of Civil Engineering
University of Moratuwa.

For the economic development of a country increase in transport industry activity is vital. This will inevitably expose a large portion of urban population exposed to automobile pollution emission. Hence, there is a great need of an emission control strategy to minimize the adverse effects due to pollution by vehicle emission.

In some parts of the world this problem has been addressed by approaches such as traffic management measures, established emission standards, effective vehicle inspection and maintenance programmes (I/M programmes), encouraging public transport, encouraging cleaner fuel and road user charges etc. Even though some of the above measures have been initiated in Sri Lanka, vehicle emission standards or effective I/M programmes are almost non-existent.

This paper discusses the present situation of vehicle emission in Sri Lanka and identifies possible measures that could be adopted to control vehicle emission by changing the vehicle technology standards. An overview of principles of automobile emission formation, main sources of emissions, the effects of the fuels used and emission related combustion chemistry is also presented.

The historical -development of motor vehicle emission control technology and the standards set by the developed nations have been analyzed to identify probable measures to control vehicle emissions in Sri Lanka in the near future with affordable technology. Vehicle emission estimates for different I/M measures, fuel types and vehicle growth scenarios are compared to identify efficient measures in emission control. In estimating vehicle emissions the guidelines given by the Inter governmental Panel on Climate change (IPCC) and emission factors developed to suit the Sri Lankan conditions have been used.

Evaluation Of The Effect Of Microbial Mixtures In Compost Making

H. M. M. Herath, S. C. Wijeyaratne
Department of Botany, University of Sri Jayewardenepura

Air dried grass clippings. leaves, coir dust, saw-dust and cow dung used as organic raw materials were treated with different microbial mixtures; a solution of Efficient microorganisms (EM) (T-1), a Mixture of Bacteria in powder from (T-2). The control had only natural microorganisms (T-0). These. treatment units were arranged in randomized block design in an in-door environment. Composting period was eight weeks. Piles were turned weekly and samples were taken for analysis. Process was monitored by measuring the temperature, pH, carbon dioxide evolution rate, C/N ratio and change in the particle sire. Weed seed germination percentage was determined with the final product.

Temperature of composting piles increased initially in all treatments. In EM treatment temperature decreased after the third week, in other two cases a temperature more than 40 °C was retained till the 7th week. In all treatments pH increased during the first four -weeks and later decreased to neutral range. During the first three weeks the mean CO, evaluation rate was higher with the EM solution treated units than with the other two. The C/N ratio significantly reduced during the process in all three treatments but the lowest value was observed in EM treatments. Further change in particle size was significantly higher in EM treatment. Weed seeds were successfully controlled in compost processed with bacteria suspension.

It could be concluded that the EM solution and Bacteria powder used in the study accelerated the process but there may be disadvantages such as high weed seed germination and unknown undesirable effects on natural flora.

Isolation And Characterization Of Cellulolytic And Pectolytic Microorganisms From Naturally Degrading Solid Waters

H. H. V. M. Sanjeevani and S. C. Wijeyaratne
Department of Botany, University of Sri Jayewardenepura.

Cellulolytic microorganisms were isolated from natural compost heaps, using different media such as Duboo's cellulose, cellulose mineral salt, cellulose agar, cellulose dextrin agar which contain cellulose as the only carbon source. Using pectin agar medium, which contained pectin as the only carbon source, pectolytic microorganisms were isolated.

Cellulolytic fungal genera isolated were Helminthosporium sp., Aspergillus sp., Cephalosporiurn sp. and Gliocladium sp. There were only cellulolytic actinomycetes (Steptomyces sp.) and one cellulolytic bacterium. Pectolytic microorganisms isolated were species of Aspergillus, Perticilliurn, Mucor. Yeast and a pectolytic bacterium. Cellulolytic and pectolytic enzyme activities of isolated microorganisms were determined using cotton wool, carboxymethyl cellulose (CMC) and pectin as substrates. Sugar produced by degradation of substrates were determined by Somogyi-Nelson micro method. Highest cotton wool degrading activity and CMCase activity were obtained from Gram negative short rod bacterium (8.899x10-3 units of enzyme/5ml and 1.2892 units of enzyme/5ml respectively). Highest pectinase activity was obtained from Penicillium sp. (ii) (0.0136 units of enzyme/5ml).

All isolated cellulolytic microorganisms showed high growth rate at 30 and 35°C while most pectolytic microorganisms showed high growth y rate at 35°C. Except for species of Gliocladium other Gellulolytic microorganisms showed high growth rate at acidic pH range (pH 4.5). Among pectolytic microorganisms Penicillium sp. (I) and Aspergillus niger showed high growth rates at pH 5.5. But Penicillium sp. (ii) and Aspergillus sp. (ii) showed high growth rates at pH 6.5.

It was clear that these microorganisms have the ability to degrade complex cellulose and pectin molecules to simple compounds but it may not be economical as they showed relatively low capacity. However it would he possible to develop a microbial mixture, using above types of native microorganisms that may have a high potential for degradation of solid wastes.

Optimal Regional Planning Approach In Solid Waste Management

P.I. Katugampola1, M. Vlach2 and J.M.S.J. Bandara3
1,3Department of Civil Engineering, University of Moratuwa, Moratuwa
2School of Information Science, Japan Advanced Institute of Science and Technology, Ishikawa, Japan

Solid waste consists of all the solid material that an urban society can no longer use constructively or economically and must be discarded in a way that is harmful to the environment. As a community becomes intensively urbanized, the problem of solid waste management gets more and more aggravated. Cost of providing waste management services is rising both as a result of scarcity of land and due to the tightening environmental regulations. An approach of waste management receiving wide attention recently is to reduce the waste disposal costs by establishing centralized facilities. Centrally operated facilities have the advantage of economics of scale that cannot be owned by smaller municipalities.

This paper investigates problems associated with the new approach of regionalization and waste diversion. It also investigates the application of linear programming (LP) and mixed integer programming (MIP) techniques for the optimal allocation of waste stream and facility scheduling of a regional solid waste management system over a fixed planning period. Waste disposal options include land filling and waste diversion through recycling and composting. The regional system consists of multiple cities, landfills, material recovery facilities. composting facilities and transfer stations.

Mathematical models used for the optimization are formulated to minimize the net present value of the cost of providing waste management services in a region. The optimization model used consists of a set of constraints defining the waste flow mass balance and capacity limitation of the facilities. It is seen that the LP approach is simple and efficient in computation time but the usage is limited due to its inability to handle discrete size for facilities and mutually exclusive situations. The MIP approach allows for formulating all possible options into a single model run. However, as the size of the problem increases, MIP approach may introduce a large number of binary variables into the model, increasing the time requirement to reach the optimum solution.

Sunday, October 08, 2006

Trace Metals In Surface Water Bodies

J.A. Liyanage and S.A.A. Perera
Department of Chemistry, University of Kelaniya


Uncontrolled discharges of heavy metals to surface water bodies pose a threat to humans, wild life, plants and to micro-organisms. In Sri Lanka heavy metals are used in a great number of industrial applications and metal waste from industry is a form of hazardous waste. This preliminary study was conducted to determine the levels of heavy metals in the surface water in Ekala area where some metal-based industries are located.

Samples were collected randomly through the drainage line from the main outlet, randomly and within two hour intervals, and also from drinking water wells around the area. Total concentrations of copper, cadmium, manganese, zinc and chromium were analyzed by flameless atomic absorption spectroscopy and lead was determined by spectrophotometry. Values were compared with untreated and treated samples.

Results show that the effluent may some times be diluted before discharge to the main drainage system and the metal content is reduced when it go far from the main outlet. Copper and Cadmium values are within the recommended levels but lead and zinc concentrations are above the Maximum Concentration Limits (MCL) for surface water.

In well water manganese and chromium were present in very low or negligible amounts. Copper and cadmium concentrations are well within the maximum tolerance limits for drinking water bur lead and zinc values are higher than the recommended values. Metal concentrations a1-e higher at the bottom level of the well water than the surface.

Tuesday, October 03, 2006

SILVICS OF Michelia Champaca (GINI-SAPU): A COMMON TIMBER TREE GROWN IN KANDYAN HOMEGARDENS OF SRI LANKA

H.M.G.S.B. Hitinayake, H.M.L.S. Dharshana and D.H.M.S.S. Dissanayake
Department of Crop Science, Faculty of Agriculture
University of Peradeniya

Michelia champaca ((Gini-sapu) is an exotic which was introduced to Sri Lanka from India and first planted around Hindu temples as an ornamental tree. M. champaca has naturalized in the mid country wet zone of Sri Lanka. It has become a popular timber tree among farmers managing Kandyan home gardens. Also it has been used for enrichment of some small forest in the Kandy area. Fewer restrictions prevail with respect to harvesting and transport of Michelia champaca timber. It is classified within the second hard wood timber.

The object of this paper is to discuss the main silvicultural features of Michelia champaca based on the results of several on going experiments conducted by the authors on the various silvicultural aspects of Michelia champaca. In addition information obtained from research publications are also included along with the citations. They include seed treatments, seed viability, storage and light requirement for seedling establishment and growth and pruning regime practiced with individual trees. Tables derived from a tree inventory conducted to estimate total and merchantable wood volumes and financial returns under standard discount rates using easily measurable parameters such as tree height, trunk diameter and age are also included here.

The experiments on seed treatments have indicated that Michelia champaca could be propagated using treated seeds. The recalcitrant behavior of seeds indicated that viability deteriorates rapidly with lowering moisture content but can be stored under low temperatures. The seedling growth and establishment rates increased with increasing light intensities and the best performance was shown under open conditions. The volume and financial value tables derived will serve as important tools in measuring timber volumes and financial values of standing trees. These tables can also be used in the identification of optimum harvesting age and size.

IN VITRO MULTIPLICATION AND ROOTING OF Artocarpus heterophyllus LAM

Artocarpus heterophyllus is an out breeding species. Therefore germination of seeds may give seedlings with vast genetic diversity. Clonal propagation of selected genotypes is very useful in maintaining selected characters.

Apical meristem from 20-30 years old jak plants were cultured in modified Campbell and Durzan (CD) medium supplemented with O.5mg/1 Indole Butyric Acid (IBA) in order to elongate shoots in vitro. After six weeks of incubation in 25±1 ÂșC (16 hr day), 60% of the explants produced elongated shoots. They were cultured on Murashige & Skoog (MS) medium containing l.5mg/l IBA and O.5mg/1 kinetin for shoot multiplication and 4-5 shoots per explant were obtained after five weeks of incubation. Non-multiplied shoots were transferred into ½ MS medium containing 1.Smg/1 IBA and l.Omg/1 Naphthalene Acetic Acid (NAA) after five weeks. If shoots were kept in the same medium (½ MS medium containing l.5mg/l IBA + l.Omg/1 NAA) for more than two weeks they will produce callus instead of roots at the base. Therefore after two weeks they were transferred into CD medium containing O.5mg/l I BA for rooting. Root initials were observed after 10 days of incubation.

CONVERSION OF THE Pinus caribeae PLANTATIONS IN UPCOUNTRY INTERMEDIATE ZONE WITH OTHER POSSIBLE TREE SPECIES

K.M.A. Bandara
Forest Department

Pine plantations in the upcountry are now in their rotation end. These plantations has been planted in comparatively degraded patana lands. At present, as a policy it was decided not to reforest the second rotation lands again with pines. Therefore the conversion of pine plantations with other suitable tree species has become priority area for study in the Forest Department.

A research project was initiated in 1994 to investigate the possibility of converting the available pine plantations to other broad leaved species. As the first phase, nine timber species, nitrogen fixing soft wood species, woody herbal species and non-woody herbal species were tested under different thinning levels (Basal area 10 m2 ha-1, 15 m2 ha-1, 20 m2 ha-1 and control). As the second phase the selected timber species from phase one (Michelia champaca, Swietertia macrophylla) and some other possible tree species (Artocarpus fraxinifollus, Eucalyptus grandis, Eucalyptus microcorys, Acacia melanoxylon and Kyaya senagalensis) were established under different levels of gap openings (4 m, 6 m and 20 m).

The initial tree growth assessment of the second phase experiment was done after IS months of planting. The fast growing exotic species E. grandis, E. microcorys and A. melanoxylon showed the highest height growth 3.0 m, 2.8 m and 1.2 m respectively under the heavy thinning level (20 m gap). Other than S. macrophylla and K. senagalensis all other tree showed a significantly higher tree height growth under the heavy canopy opening conditions.

INVASIVE BEHAVIOUR OF Myroxylon balsamum AT UDAWATTAKELE FOREST RESERVE

H. P. Wedathanthri and H.M.G.S.B. Hitinayake
Department of Crop Science
Faculty of Agriculture
University of Peradeniya

Udawattakele forest is a national heritage of Sri Lanka which has rich flora and fauna. There are about 460 plant species including 135 tree species and i l liana species, of which 9 species are endemic to Sri Lanka. When considering floristic composition of Udawattakele it is dominated by Swietenia macrophylla (mahogany), Michelia champaca (gini-sapu), Mesua ferrea (na) and Myroxylon balsamum (katta kumanchal). Senadhera (1997) has reported that Myroxylon balsamum has become invasive in some parts of the forest. The objectives of this investigation was to estimate the invasive behavior of Myroxylon balsamum at Udawattakele forest reserve.

Plots of 10 m x 15 m were used for sampling of over story vegetation and 10 in x 10 m plots were used for under story. Plots were located randomly in Myroxylon balsamum dominant regions in the forest and measurements taken were number of individuals and their species. tree height (m), stem diameter (m) at breast height (1.3 m above ground level) and crown diameter (m) in order to evaluate species diversity and dominance. Germination of Myroxylon balsamum seeds were evaluated under four different light levels (full sunlight, 70%r and 35% light and complete dark conditions). A map was prepared to show the distribution and density of Myroxylon at various parts of Udawattakele forest reserve.

Results showed- that Myroxylon has dominated the understory even when a few mother plants were available in the overstory. This could be attributed to prolific seed production capacity, its ability to germinate under wide range of light conditions, favorable microclimatic conditions presenting in the understory and absence of any seed pest or pathogen. Further results clearly showed that Myroxylon invasion had resulted in the decline of species diversity of the forest.

If no control measures are applied, there is a possibility that this species could invade the other parts of the forest in the long term. Therefore necessary action must be taken immediately to control Myroxylon balsamum. This could be done by uprooting seedlings, collecting and destroying seeds and thinning some mother tree,. Further understanding of the efficiency of key physiological processes of Myroxylon including water use efficiency and stomatal conductance could be useful in deciding measures to control the invasion. Further examinations of the dynamics of the Myroxylon seedling bank and competition taking place at some parts of the forest between mahogany. Myroxylon and na for the dominance could be useful in the management and maintenance of the species diversity of Udawattakele forest reserve.