Biomass estimation in some dry zone forests in Sri Lanka from Forest Inventory Data

M.D.P. Kumarathunge and M.C.M. IqbalPlant Biology, Institute of Fundamental Studies, Hantana Road, Kandy, Sri LankaTropical forests are a major sink for carbon dioxide produced globally. Estimation of above-groundbiomass of these forests is an essential aspect of studies of carbon stocks and the effects of carbon sequestration on the global carbon balance. Long term monitoring plots across several tropical dryevergreen forests in India, in the recent past, shows they are highly carbon dense ranging from 73.06Mg ha-1 to 173.1 Mg ha1. In Sri Lankan forests, biomass estimates are confined to the wet zone forestsand plantations.To assess the carbon dynamics in Sri Lankan dry zone forests, as a pilot study, above-ground biomass infive dry zone forests were estimated using past forest inventory data from 1961. Our objective was todevelop an above-ground carbon database for dry zone forests, which can be used to determine the carbon dynamics in those forests. The data of published stand and stock tables from the five dry zoneforests, Hurulu, Kumbukkan, Kantalai, Pallekelle and Madhu, were converted to above ground biomassusing published allometric models. Estimated above-ground biomass ranged from a minimum of 75.7Mg ha-1 in the Kumbukkan forest to a maximum of 129.6 Mg ha-1 in the Kantalai forest. The total abovegroundcarbon stocks ranged from 37.8 Mg ha-1 in the Kumbukkan forest to a maximum of 64.8 Mg ha-1 inthe Kantalai forest. The average above-ground biomass for dry zone forests was 92.62 Mg ha-1. Whencompared with the wet zone estimates (eg.Sinharaja 336.8 Mg ha-1) the dry zone forests have lowerabove-ground biomass due to high disturbances, low tree density and other factors such as slow growthpattern of most of the tree species. However, present above-ground biomass estimates are not availablefor dry zone forests and estimates from this study can be considered as the above-ground carbon stock1960’s. These estimates shall be presented to assess the carbon dynamics in dry zone forests of SriLanka.

Download the status of the Environment book

This Status of the Environment assessment for Sri Lanka provides a basis for the development of action plans, the next stage of the planning process.  The report aims to provide guidance for action planning, policy setting and resource allocation for the coming decades to improve the state of the environment of Sri Lanka and the welfare of her people.

The five key environmental issues identified for Sri Lanka are (1) land degradation by soil erosion, (2) waste disposal, (3) pollution of inland waters, (4) loss of biodiversity, and (5) depletion of coastal resources.

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Sinharaja Forest nominates for New 7 Wonders of Nature

The Ministry of Environment and Natural Resources has called upon all Sri Lankans to vote for the Sinharaja Forest to be included among the `New 7 Wonders of Nature`. Voting for nominees will continue until 31.12.08. The New 7 Wonders Panel of Experts will then select 21 finalists, from which voters worldwide will elect the New Seven Wonders of Nature. People can vote for the Sinharaja Forest by going to the link:

Sustainable Agricultural Practices in Sri Lanka

Dr. P.B. Dharmasena
Field Crops Research and Development Institute, Mahailluppallama

Sri Lanka is still and will be for near future considered as a country dependant mainly upon agriculture including plantation sector. Challenges posed by external factors due to globalization and open economic policies have directed the country’s agriculture to move away from the self reliance. Competitive export and import opportunities among countries have led to maintain the standard levels of quality and steady levels of production at a lower price in all commodities. This situation demands a firm and perfect policy for country’s agriculture. Further, present agriculture does not show any indication of sustainability as it has ignored the centuries old wisdom of traditional agriculture. In developing a strategic mechanism to promote an alternative to present agriculture, cognizance must be taken from deep rooted customs and traditions and the time tested agricultural practices to assure the sustainability in the agricultural sector.  Farmers’ dependency mentality evolved due to modern agriculture and the government policies dealt with agriculture from time to time should gradually be removed by developing self confidence, self motivation and empowerment.

Most critical issue at present is that the agriculture does not bring a consistent economic gain to the farmer. Import export policies do not respond effectively to maintain profitability of farming.  Farming without adequate concern on conservation of natural resources such as soil and water and environmental protection has led to deterioration of the agricultural resource base in the country and pollution of the environment. Government has not paid adequate attention to provide farmers with input and marketing facilities in time.  Land resource is utilized for various purposes including agriculture with out considering its suitability, capability and vulnerability to degradation. Farmers are not much aware of the current trends in agriculture, marketing and technologies.

Policy Aspects

Need is felt for urgent attention to formulate a firm policy to implement sustainable agricultural production program in the country. In policy statements on various sectors of the agriculture following aspects should be included to assure conservation and efficient utilization of soil and water resources.

In irrigated agriculture water losses from reservoirs and canals should be minimized, efficient field water management has to be promoted for increasing the water productivity through crop diversification and with new water saving techniques. In rain fed agriculture the unirrigable land mass of the country should be developed on watershed basis with proper soil and water conservation techniques, put into most suitable land use forms such as agro-forests, perennial orchards, field crop farms, mixed timber plantations, pasture lands etc. State resources should be mobilized to make these lands productive with sustainable rain fed agriculture to benefit farmers on short, medium and long run.
Organic farming should be encouraged to reduce adverse effects of agro-chemicals and inorganic fertilizer on environment and human health by expanding the organic farming sector, creating awareness in general public for consumption of organic products, generating new technology and certifying products, processing and packaging to earn foreign exchange and gain high price to the farmers. Integrated farming should be introduced to farmers for optimum use of their resources, year round steady income and effective use of residues.  The policy on integrated farming towards sustainable agriculture should be to improve village level productive farming, discourage artificial products and chemical use, familiarize livestock farming and encourage cottage industries to capture foreign and local market with traditional products.

Sustainable agriculture policy should stress the importance of conserving natural resources (land, water, forest, atmosphere etc.), while utilizing them effectively for agricultural production. All land users for agriculture should be encouraged for sustainable use of natural resources by awareness creation, making resources conservation compulsory, generation of improved technologies, safe and efficient management of rainwater, river, tank and groundwater.

Agriculture should be mechanized in all possible ways to reduce the cost of production and improve the quality of produce but with no harmful effects on natural resources such as wind and water erosion, increased water and soil nutrient losses, air pollution etc.

National policy on agriculture should emphasize the use of indigenous knowledge in agriculture, which ensures preserving and utilizing traditional crops and varieties, resources conservation practices, medicinal plants, cottage industries and agricultural heritage of the country.

Strategies to Achieve Sustainability in Agriculture

In implementing what is spelled out in a policy various strategies need to be identified.  Following activities need much attention to achieve sustainable agriculture production in Sri Lanka with special reference to soil and water conservation.

Lands potentially suitable for agriculture should be given priority for agricultural production to assure the land resource availability for future expansion of agriculture. Primary and secondary forest lands should not be exploited for any purpose other than development of forest vegetations. Decision makers of agricultural production planning should not consider only the national production requirement but also the sustainable production levels of resources including farmers. Thus, food production expectations should aim at national food security, but not always at reducing outflow of foreign exchange for food imports.

Increasing agricultural productivity should not jeopardize the land, water and other resources of the country. Since many ministries bear the mandate of conserving natural resources there is a necessity to establish a national advisory board for conservation of natural resources independent of political authority.

A national development plan for agriculture has to be prepared wherein integrated approach of agriculture, livestock and small agro-based industries is promoted. Any agriculture related activity implemented in the country should be a part of the national agriculture development plan. Committees should be established at provincial, district, divisional and village level to plan and implement the agricultural production program.  Farmers should be protected from adverse effects of free trade policies and globalization.

Reorientation of Research Agenda

In identifying areas for research under the theme of alternative agriculture for self reliance most essential knowledge urgently needed can be obtained by answering following ten research questions.

1.    How can the negative impacts of globalization and trade liberalization be managed locally to achieve sustainability in agricultural production?
2.    What land and water resources are available in quantity and quality in different parts of the country?
3.    How they could be developed and allocated for different purposes among competing interests?
4.    What governance framework and institutional mechanisms (policy, legal and organizational frameworks) are needed to create an environment for cost-effective interventions of sustainable agriculture?
5.    What is the relationship between poverty and environmental degradation?
6.    How poverty can be alleviated through sustainable agriculture?
7.    How can the impacts (environmental, social and economic) of land use changes be assessed?
8.    What combinations of technological and management strategies are needed to assure the utilization of natural resources effectively, efficiently and equitably for agriculture to alleviate poverty and enhance environmental security?
9.    How a community can feel and realize an improving process of sustainability?
10.    What Decision Support Information Systems are needed to empower the stake holders in implementing sustainable agricultural development programs?

Reorientation of agricultural research agenda from crop based to resource productivity based is essential to achieve sustainability. Promotion of endemic fruits, vegetables and medicinal products for both local consumption and foreign markets can be initiated through research. Knowledge on conservation of natural resources at present is dispersed and available in various institutions.  Gaps need to be identified where further studies are needed and organized by networking them so that any would have the access for utilization.

Theme talk made at the Tenth Annual Forestry and Environment Symposium held at Kabool Lanka International Training Center, Thulhiriya on 2nd and 3rd 2005 organized by Department of Forestry and Environmental Science, University of Sri Jayewardenepura

Recent Trends in the Forestry Sector of Sri Lanka

Mr  H  M  Bandaratillake
Director, Forest Resources Management Project
Ministry of Environment & Natural Resources

The forest cover in Sri Lanka has been continuously declining during the last several decades.  The forest cover which was around 44% of the land area in 1956 had declined to 23.9% in 1992 and 22% at present.  It has been widely accepted that this rate of deforestation has caused one of the main environmental and social problems in the country.  Although, successive governments have taken many steps to conserve forests and to introduce laws and regulations to control deforestation, the problem was aggravating from year to year without effective solutions, mainly due to the conflicting demands placed on forest resources.

In view of this situation, the National Forest Policy was revised and Forestry Sector Master Plan  (FSMP) was formulated and approved by the government in 1995.  The Forestry Sector Master Plan (FSMP) which was based on the National Forest Policy, provides the framework for developing partnerships with non state sector for promoting community and private sector participation in forest conservation and development. FSMP also provide a guiding framework to introduce new policies and to carryout legislative, administrative and institutional reforms required.

The Forest Resources Management Project (FRMP) which is scheduled to implement during 2001- 2007 is the first implementation programme of the FSMP. The overall objective of the FRMP is to establish and operationalise participatory sustainable forest resources management for increasing forest protection and production. With the implementation of  FRMP, number of new strategies and programmes have been introduced to the forestry sector in order to achieve the objectives of sustainable forest management.  Some of these strategies include;  private sector re-forestation and management, woodlot development, establishment of Permanent Forest Estate, Re-organisation of the Forest Department, Amendments to the Forest Ordinance, Private sector harvesting of forest plantation and development of nature tourism etc,.  Legal provisions including mechanisms for benefit sharing have been provided to facilitate the effective implementation of these programmes.

Theme Seminar Presented at Forestry and Environment Symposium 2005, Organized by Department of Forestry and Environment Science, University of Sri Jayewardenepura, December 2005, Thulhiriya, Sri Lanka

Pollution Control and Waste Management in Sri Lanka

Dr. W.L. Sumathipala

Senior Lecturer, The Open University of Sri Lanka and
Director National Ozone Unit, Ministry of Environment

The magnitude of degradation of the environment increased tremendously with the industrial revolution which started in 1850s.  Even prior to the industrial revolution, pollution due to human activities existed but in a reduced amount.  Those days the assimilation capacity of the environment was greater than the release of pollutants in to the environment.  Large volumes of wastes were released in to the environment with the development of machine-based industries.  Then the assimilation capacity of the environment became lower than the rate of waste generation.  As a result wastes accumulated in the environment giving rise to problems, which threatens the life existence on planet Earth.

In general, pollution can be considered in terms of Air Pollution, Water Pollution and Land Pollution.  Scientists are also considering some specific types of pollution such as pollution due to Noise, radiation and high temperature.

Since there are no boundaries in the atmosphere air is not limited to a place, region or to a country.  Therefore air pollution produced in some parts of the world can cause problems in another country in the world.  Therefore air pollution should be considered as a major problem where international efforts are needed to address the atmospheric problems. Further it is considered to be a serious problem as it affects the human health worldwide.  All the terrestrial life forms are exchanging gases with the atmosphere.  Therefore there is a danger of inhaling/absorbing what ever the pollutants available in the atmosphere because they do not have a filtering mechanism.  On the other hand the pollutants released in to the atmosphere gets diluted and the possibility of collecting or treating such pollution is impossible.  Therefore preventing, controlling or treating these substances before releasing them in to the atmosphere is very important.  The atmospheric lifetime of some pollutants/chemicals is very high and they cause global environmental problems such as Ozone Layer depletion.

The main sources for air pollution are burning fossil fuels for energy generation & transportation, biomass burning and industrial emissions.  The sources of air pollution give rise to gases, mixtures of fine particles or both.  Most common gases generated from burning fossil fuels are CO2, CO, Oxides of Nitrogen, Oxides of Sulfur and unburned hydrocarbons. Pollution due to biomass burning for cooking is very common in the Asian region.  This will generate unburned hydrocarbons due to incomplete burning processes, mixture of oxides of carbon, nitrogen & sulfur and particulate matter.  Industrial emissions are responsible for most hazardous chemicals such as fluorinated carbons, PFCs, SF6, etc.

Considering the difficulty of treating these gasses after releasing in to the atmosphere it is important to either control or treat the emission before releasing to the atmosphere.  In the industrial sector, controlling the emission of air pollutants can be achieved through changing the method of plant operation, changing the input or raw materials used in the process, adopting cleaner production methods or treating the pollutants prior to release.  Gaseous pollutants can be removed from their gaseous environment to either a liquid or a solid surface, where they will be preferentially retained, or where they react to form a non polluted species.  There are processes with various methods used for collecting gases with high concentration such as absorption in to a liquid or solid or adsorption on to a solid surface.  These are occurring either with or with out reaction.  Pollutants generated due to incomplete combustion can be removed through complete combustion converting them into CO2 and water.  This can be achieved in a combustion chamber providing sufficient air in the presence of a catalyst.  In order to prevent the release of particulate matter to the atmosphere, settling chambers, gravity separators, cyclone dust collectors, filters, wet scrubbers and electro statistic precipitators can be utilized.

Emission of radioactive particles is possible due to the development of energy generation through nuclear power plants.  Since these materials cannot be detected by human senses such as taste or smell and even a very minute quantity is lethal, there has to be stringent regulations utmost in operating these plants and handling waste.  These should operate on hundred percent accident free environments.  In addition, installation of multiple barriers, real time monitoring and error free safeguard systems are very important for these facilities.

Indoor air quality is very important, mainly because people remain indoors in excess of 90% of their lifetime.  Common indoor pollutants are Paints, Varnish, polish, household polymers, fuel wood burning, burning incense sticks and mosquito coils.  Houses or buildings with less ventilation are vulnerable for indoor air pollution resulting in nausea, vomiting, dizziness and respiratory diseases.  As a solution, Architects can design well-ventilated buildings with more air circulation.

Substances such as CFC, Halons, CTC, HCFC are depleting the Ozone Layer that protects human from the Sun’s dangerous UV radiation.  Increase of Greenhouse gases such as Fluorinated Carbons, Methane, and Nitrous Oxides in the atmosphere is making the earth atmosphere warmer resulting in climate change and sea level rise.  Global commitment is essential in order to control such global environmental problems.  Montreal Protocol and Kyoto Protocols are major global agreements to take action in order to control these two major environmental problems.

Water is a basic requirement for sustaining life.  Out of the total volume of available water in the planet, less than 1% is suitable for human consumption.  This limited resource is further reduced due to human activities, which make it unusable.  Main sources of water pollution are release of industrial waste, dumping solid waste, sewage, human waste including faecal matter, sediment run off due to soil erosion etc.  As a result of such activities, concentration of dissolved carbons, heavy metals, biohazards such as bacteria and virus and other nutrients will increase in the water sources resulting in loss of biodiversity and making the water unsafe for consumption.  Several methods have been developed for water treatment once it is polluted.  Biological treatment, chemical coagulation and filtration, carbon adsorption, chemical oxidation, ion exchange, electrodialysis, reverse osmosis, air stripping are some of them.  Water bodies are also being polluted due to discharge of sewage from watercrafts and oil spilling around the world.  Designing holding tanks for receiving and storing sewage until they can be unloaded on the shore is one controlling method.  Large vessels can be equipped with biological treatment plants.  Leaks from offshore drilling and accidental oil spills are possible resulting in threat to water creatures and large-scale killing of sea birds.  Surrounding the oil slick with a mechanical barrier until it can be removed, collecting the oil by mechanical means such as suction pumping or absorption by a suitable material and dispersing the slick with chemicals are methods practiced today.

Environmental problems due to solid waste are a growing problem in Sri Lanka and it is a major problem in many of the developing countries.  Current rate of waste collection by the local authorities in Sri Lanka is estimated to be about 2,500 tones per day.  Rate of waste generation depends on a number of factors such as socio economic conditions, public attitude towards reuse and recycling of waste and geographical and physical factors.  Due to the improvement of technology, a tremendous increase in non-degradable packaging materials such as plastic, polythene, metals and glass can be seen.  Solid wastes are generated from domestic, institutional, market, medical, commercial, industrial and garden sources. Industries such as food, paper, cardboard, rubber, and leather are good sources of organic waste. A greater portion of commercial and domestic waste are organic and biodegradable.  The major problem in relation to solid waste is uncontrolled disposal of wastes.

Toxic and hazardous wastes are generated mainly from industrial and medical sectors.  The extent of land pollution increases due to unorganized solid waste disposal practices.  Developing facilities for safe disposal and management of solid waste should be a high priority in society.  With the rapid development, population growth and urbanization, solid waste has increased and therefore it is essential to manage solid waste.  There is also a serious threat of utilizing Sri Lanka as a hazardous waste dumping site.

According to the estimates the local authorities collect only a part of the waste generated.  Disposing wastes in the home gardens are common in rural areas due to lack of collecting system or facilities.  At present waste disposal is mainly in open dumps, which are unsanitary.  Most of these areas are low laying marshy lands and abandoned paddy fields.  As a result leachate, emission of gases, odors, fire and loss of aesthetic beauty are possible.  As an alternative to open dumping, sanitary land filling has to be introduced.  Proper planning is essential to minimize the side effects.  Separation of solid waste at the point of generation is essential and thereafter different categories can be treated separately.  Biodegradable materials have to be composed and used as organic manure as far as possible.  Avenues for collecting recyclable materials and recycling should be promoted.  The final waste that is not possible for recycle has to be dump in a sanitary landfill.  Incineration is another option but the capital cost is very high and therefore it may not be suitable for a developing country.  At least several small-scale incinerators are essential to destroy toxic and hazardous waste.

Noise pollution has a very close relationship with occupational safety.  In most cases industries are responsible for high noise pollution.  Recent studies show that there is direct relationship with high levels of noise and mental health.  Noise management can be achieved at the point of its origin and along the noise pathway and at the point of reception. There are several noise management techniques available at present.  Shock absorbing techniques, use of non metal parts to reduce the noise generated, use of acoustic guards, installing machinery on adequate mountings, locating machinery away from the residential areas are some of precautionary methods.

In most of the industries a large amount of heat is generated and released in to the atmosphere.  This problem of thermal pollution can be alleviated by using artificial cooling ponds or cooling towers.  Where possible this high temperature can be utilized for useful work such as generation of electricity.

In order to control pollution, proper and appropriate legislation, emission and effluent standards for industries are essential.  Awareness creation among the general public and making the man more environment friendly is an over all approach for environment protection.

Theme Seminar Presented at the Forestry and Environment Symposium 2005, Thulhiriya, Sri Lanka, 2-3 December 2005

What can you do for Environment Friendly Living

What Can You Do…

  • to Help Sustain Soils?
  • to Promote More Sustainable Agriculture?
  • to Help Reduce Pesticide Use and Exposure?
  • to Control Common Insect Pests and Weeds?
  • to Reduce Outdoor and Indoor Air Pollution?
  • to Reduce Water Waste?
  • to Reduce Water Pollution?
  • to Reduce Solid Waste?
  • to Reduce Hazardous Waste?
  • to Help Preserve Biodiversity?
  • to Be a Responsible Ecotourist?
  • to Help Protect Endangered and Threatened Species?
  • to Waste Less Energy?
  • to Help Protect Your Health?
  • to Reduce the Threat of Climate Change By Reducing Carbon Dioxide Emissions?

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Evaluation of different cover crops on vacant areas (pottal) in mature tea plantation

I R Palihakkara, B G D Udesh, P W D Vithanage
Department of Crop Science, University of Ruhuna, Sri Lanka.
Didenipotha estate, Maturata plantations Ltd., Sri Lanka

An experiment was conducted at a low country tea plantation in Matara district to Evaluate different cover crops species for vacant areas. It was conducted during the period of January to June 2006; the selected site was 2nd year after pruning, T.R.I 2025 that was establishing in 1980 and the field with lot of vacant areas.

Six cover crop species (Desmodium triflorum, Arachis pintoy, Desmodium heterocarp, Vetiveria zizaniodes, Crotalaria ochroleuca, Cymbopogon nardus) were selected for the experiment. The experiment followed a Latin Square Design. Trees planted in vacant areas, with the space of 6 inches for 1,2,3, spp and 8 inches for 4,5,6 spp. Data were collected one month after the establishment.

Soil nitrogen content, pH, biomass production and soil organic matter content were measured. Weeds count was taken two weeks interval. Survey was conducted to evaluate workers preference level of the each cover crop.

There was no significant difference within the treatments in soil pH, organic matter % and soil N %, but Vetiver was found to be suitable for acid soil (p>0.05). Organic matter added by D. heterocarpon, D. triflorum was significantly higher than other species. D. heterocarpon and Crotalaria was highly effective in improving the soil N among the legumes. Before the experiment soil C: N was 7:1. D. triflorum improved the soil C: N (10.7:1) during research period.

In generally workers did not like cover crops. However they preferred legume rather than grasses. 60% of the workers selected D. triflorum as their first choice. 26% of the workers selected A.pintoy as their first choice. D. heterocarpon, C. ochroleuca, and C. nardus were selected by only 3%. Workers did not select vetiver as their first choice. Dry matter production of grasses was higher than that of legumes. V. zizanioides, D. triflorum had approximately similar shoot: root ratios.

Treatments effect for weeds population was not significant (p>0.05), but A. pintoy, D. heterocarp were fast growing and suppressed the weeds than other legumes. It was concluded that workers preferred four legume species rather than two grasses. A. pintoy, D. heterocarpon, C. nardus can aggressively suppress the weeds. D. heterocarpon, D. triflorum were highly improved soil nitrogen and organic matter than other legumes during the research period.

Assessment on timber and carbon in rubber plantations with special reference to the wet zone of Sri Lanka

E S Munasinghe, V H L Rodrigo P K W Karunathilaka and U A D P Gunawardena
Rubber Research Institute of Sri Lanka.
Department of Forestry and Environmental Science, University of Sri Jayewardenepura, Sri Lanka

Rubber (Hevea brasilensis) has traditionally been cultivated for the latex extraction; however, its importance in other uses, particularly producing quality timber and sequestering atmospheric carbon as a permanent sink, is also often highlighted. The amount of timber produced and carbon sequestered in rubber trees has been assessed in isolations. Those values would differ under different growth conditions and to date, no simple protocol is available to quantify the amount of timber and carbon in rubber plantations. Therefore, the study reported here was aimed to develop simple growth models to assess the timber production and carbon fixing capability of rubber plantations in Sri Lanka.

Initially, a growth function was developed to assess the girth development with respect to age and thereafter another three functions to quantify the amount of timber, biomass and carbon in the rubber tree based on girth diameter. Also, wood density variation with age of the tree was modeled to determine the biomass in timber under different age categories. The assessment on the available carbon was based on the carbon content in unit biomass and the total amount of biomass in the tree. Growth data required for the girth development function were gathered from secondary sources and girth measurements made on existing rubber clearings. Destructive sampling was conducted to assess the timber, biomass and wood density.
Based on above models, an average rubber tree at 30 years achieves a girth of 88.64 cm and produces 0.656 m3 of timber and 594.46 kg of biomass. The amount of atmospheric carbon fixed in timber at this age was estimated as 193.7 kg per tree and 45.86 MT per hectare. However, total amount of organic carbon fixed in above ground components was 220.8 kg per tree and 52.27 MT per hectare. The models of this study were developed under general conditions in the wet zone, hence should be validated for drier regions of the country before any wide scale adoption.