Determination of Rotation Period and Scheduling Harvesting and Replanting

Abstract of a presentation conducted by

Gimhani Danushika

Department of Forestry and Environmental Science

University of Sri Jayewardenepura, Sri Lanka

The objectives in forest management are often achieved by controlling the characteristics of a forest stand or set of forest stands in to influence the growth and yield of those stands. Further according to the objective of the land owner, it will change optimal rotation period of the plantations rotation. Most government owned plantations are following biological rotation to determine harvesting age of the plantation while commercial plantations are managed with economic rotation to get maximum economic benefit.

Harvest scheduling is a traditional exercise carried out by forest land managers on public and private lands. Public land management has characteristically balanced timber and non-commodity forest production while private land is going for optimal timber production. Therefore, industrial plantation establishment has been dominated by profit maximization and cost reduction by various strategies like economies of scale. Forest harvest practices in Sri Lanka are conducted by two ways called thinning and final harvesting. Final harvesting can be done in different ways such as clear cutting where all trees are felled, while selective cutting, shelterwood cutting and seed tree cutting are also possible. Thinning generate additional intermediate income from plantation while improving site quality for plant grooving by reducing competition.

Replanting of a harvested site is an important managerial activity which depends on social, cultural, economic and environmental considerations. According to management decision, it can use the same species as before or different species appropriate to the land. When replanting is carrying out, proper silvicultural practices should be maintained to gain the final harvest as expected levels. e:g: nursery establishment and maintaining, establishment of pits for planting, spacing, block wise replanting, weeding, fertilizing, irrigation, thinning and pruning etc. All these action should be conducted in proper way to maintain good replanting practice in harvested land.

Land Evaluation and Species-Site Suitability Determination for Forest Plantation Establishment

Abstract of a presentation conducted by

Sohani Vithanage

Department of Forestry and Environmental Science

University of Sri Jayewardenepura, Sri Lanka

Decisions about the use of land have always been a part of human society. Forestry planning has always taken account of the influence of conditions of land in taking management decisions. The approach and methods of land evaluation were developed in order to provide a systematic framework for assessing the effects of land on potential benefits of each land use. Land evaluation is based upon a comparison between land use and land type. Land use related to forestry can be broadly categorized as production forestry, conservation forestry, recreational forestry and community forestry. These major land uses can be further described in detail according to tree species, silvicultural methods, harvesting practices etc. The focus of land evaluation is to access the requirements and limitation of each of this land use and to compare this with the properties of land.

In the process of land evaluation land use requirements for each identified land utilization type is defined. Simultaneously, land qualities and characteristics of each land unit is described using literature surveys and ground surveys. These data is then coupled with economic and social data to develop a comprehensive comparison of land use with land. The outputs of land evaluation can be presented in terms of land suitability classifications or land suitability maps. At present, this procedure can be carried out with the help of computerized land evaluation systems and geographic information systems. In determining the species site suitability for forest plantation establishment, three aspects have to be considered. They are purpose of plantation, species availability and environmental conditions. For this process, depending on the species and sites, information survey can extend from local level to international level.

Land Evaluation and Species-Site Suitability Determination for Forest Plantation Establishment

Abstract of a presentation conducted by

Sohani Vithanage

Department of Forestry and Environmental Science

University of Sri Jayewardenepura, Sri Lanka

Decisions about the use of land have always been a part of human society. Forestry planning has always taken account of the influence of conditions of land in taking management decisions. The approach and methods of land evaluation were developed in order to provide a systematic framework for assessing the effects of land on potential benefits of each land use. Land evaluation is based upon a comparison between land use and land type. Land use related to forestry can be broadly categorized as production forestry, conservation forestry, recreational forestry and community forestry. These major land uses can be further described in detail according to tree species, silvicultural methods, harvesting practices etc. The focus of land evaluation is to access the requirements and limitation of each of this land use and to compare this with the properties of land.

In the process of land evaluation land use requirements for each identified land utilization type is defined. Simultaneously, land qualities and characteristics of each land unit is described using literature surveys and ground surveys. These data is then coupled with economic and social data to develop a comprehensive comparison of land use with land. The outputs of land evaluation can be presented in terms of land suitability classifications or land suitability maps. At present, this procedure can be carried out with the help of computerized land evaluation systems and geographic information systems. In determining the species site suitability for forest plantation establishment, three aspects have to be considered. They are purpose of plantation, species availability and environmental conditions. For this process, depending on the species and sites, information survey can extend from local level to international level.

Site Quality Improvement in Forest Management

Abstract of a presentation conducted by

Kushani Perera

Department of Forestry and Environmental Science

University of Sri Jayewardenepura, Sri Lanka

The productivity of a site for tree growth is usually evaluated on a stand basis. Considered in this way, site quality expresses the average productivity of a designated land area for growing forest trees. A common way of expressing relative site quality is to set up from three to five classes, or ordinal ranks, such as site I, II and III. The characteristics of each class must be defined to enable any area to be classified.

Site is a complex of physical and biological factors of an area that determine what forest or other vegetation it may carry. Sites get degraded due to many reasons, especially due to human induced problems such as land clearance, clear cutting and deforestation, agricultural depletion of soil nutrients through poor farming practices, livestock including overgrazing, dumping of non-degradable trash, plastics etc.

Site quality is a measure of relative productive capacity of a site for a particular species.Different site gives different growth response to different species. Site quality can be influenced by climatic factors, topographic factors, soil edaphic factors and competition. Monitoring site quality is important to match the species with the site, to estimate the quantity (harvest prediction) and the quality of the timber, to monitor overall ecosystem productivity, diversity and resilience and to check the habitat type and quality.

Site quality can be evaluated by both direct (actual crop production) and indirect factors (plant indicators, crop statistics, site factors).The quality of the original site can be improved by using several silvicultural practices like fertilization, improving the quality of soil by using cover crops, mulches and mechanical methods such as plouging, harrowing and deep ripping of the soil to improve aeration and at the same time mixing the organic matter content of the soil.

Non Timber Forest Products Manufacturing and Marketing with Special Reference to Aromatic Oils

Abstract of a presentation conducted by

T Venukasan

Department of Forestry and Environmental Science

University of Sri Jayewardenpura, Sri Lanka

Non-timber forest products (NTFPs) are any product or service other than timber that is produced in forests. They include fruits and nuts, vegetables, fish and game, medicinal plants, resins, essences and a range of barks and fibres such as bamboo, rattans, and a host of other palms and grasses. Here forest products can be classified into two main pats timber and non-timber forest products where scope of this study remains at essential oils mainly focusing on Agarwood and Sandalwood.

Agarwood is aromatic, dark, fragrant resinous substance that is produced by certain plant members of family Thymaleaceae including specially Gyrinops and Aquilaria trees. It has a high demand in globally and considered as the most expensive wood in the world. Agarwood resin formation due to natural reasons is rare and slow. Therefore resin formation is induced at commercial scale using different techniques. Both the quantity and quality of Agarwood resins is dependent on the inducement technique and therefore the use of the right method is vital to increase the product quality and income. Sandalwood oil is extracted from wood and roots of the tree. Sandalwood oil has a characteristic sweet, woody odour which is widely employed in the fragrance industry, but more particularly in the higher-priced perfumes. And also it is used in aromatherapy, cosmetic industry and to prepare soaps due to the antimicrobial activity. Unlike other aromatic wood they retain their fragrance for decades.

Citronella oil production can be highly promoted among local communities though it has been declined as it makes high profits in international market. Citronella oil is a source of important perfumery chemicals which find extensive use in soap, perfumery, cosmetic and flavouring industries. Leaves of Citronella plant are distilled to obtain valuable oil. It is a common mosquito repellent and also used in indigenous medicine as well as in flavouring food and alcoholic drinks in certain countries.

When considering the international market of aromatic oils, the current global value of the Agarwood trade is USD 6-12 billion. The annual supply of all forms of good quality Agarwood is about 6,000 MT which is 40% of the actual demand. Current market leaders in exportation of Sandalwood oil are India and Indonesia, while United States and France are the two largest importers of Indian Sandalwood oil. Although illegal logging is a major problem faced by the local industry, establishment of commercial S. album and Aquilaria plantations have recently become popular among the private sector. When Citronella oil is considered, Indonesia and China are the current suppliers for the global market. With proper technology and government support, Sri Lanka has the opportunity to become a potential exporter of Citronella oil.

Forest Certification and Challenges Faced by the Forest Owners

Abstract of a presentation conducted by

Kalani Nayanthika

Department of Forestry and Environmental Science

University of Sri Jayewardenepura, Sri Lanka

Forest certification is a process which results in a written certification being issued by an independent third party, attesting to the location and management status of a forest. It is a powerful marketing tool and widely recognized as a useful component to stimulate movement toward sustainable management. Forest certification originated in the early 1990s as a means to protect forests from exploitative harvesting.

By certifying the management of certain forests, wood products made from that timber could be labeled as “certified”. It involves assessing the quality of forest management in relation to a set of predetermined principles and criteria. It provides consumers a credible guarantee that the product comes from environmentally responsible, socially beneficial, and economically viable sustainably managed forests and also ensures that management does not diminish the value of the future forest, nor create hardships for local communities.

Certifying the forest has now become an increasing tread which provides financial, environmental and social benefits.

There are three types of forest certifications called as Forest Management, Group Certification and Chain of Custody. There are also several Forest Certification Programs in the world. The Forest Stewardship (FSC) certification is one of the popular program used in worldwide.

The global FSC standard is comprised of ten principles that cover a range of environmental, social, and economic criteria. Although there are regional variations on how the standards are applied to address the unique needs of forests, peoples, and economies in different parts of the world, the basic tenets remain the same.

From the sustainable practices followed in certification process, several social, economic and environmental benefits can be achieved. There are several opportunities which can be achieved from this certification such as increase image of the product.

There are also several challenges with regard to this certification processes such as difficulties in maintaining chain of custody from forest to the customers, difficult to justify the cost of certification. Most companies are curious or unclear about the benefits and opportunities they can derive through certification, effects from the surrounding areas where there are no sustainable practices and changing standards with time.

Control of Insect Pest Incidences in Commercial Forestry

Abstract of a Presentation conducted by 

Tharindu Dilshan

Department of Forestry and Environmental Science

University of Sri Jayewardenepura, Sri Lanka

Commercial forestry aims to get maximum production of timber or other forest products as a business enterprise. However pest outbreaks cause devastating losses in commercial forestry sector. Therefore the pest outbreaks in commercial forest plantations should be controlled in effective manner.

In nature, most insect species are in a balance. However with catastrophic influences this natural balance can change favoring the insect species. This type of insect pests are called as indigenous insect pests. The introduction of new pests can also be catastrophic to natural environments, particularly where similar species do not occur naturally. Those type of insect pests are called exotic insect pests.

Teak skeletonizer, teak defoliator, teak stem borer and Hypsipyla shoot borers in Meliaceae are several insect pests which are causing damages to the Sri Lankan forest plantations.

Monitoring of insect pest diseases in forestry primarily can be done in three ways such as mechanical control, biological control and chemical control. In the late nineties, with the awareness about adverse effects of chemical control of insect pests integrated pest management concept was formed. Integrated pest management has two processes called decision process and action process. In decision process, a rational decision should be taken with available data. Then in the action process the decision comes in to the action. There are two strategies using here such as preventive strategies and suppression strategies. Under preventive strategies regulatory, cultural and genetic tactics are using prevent the insect pest incidents. Under suppressive strategies methods such as mechanical, biological and chemical control are using. The important thing is in integrated pest management, chemical control methods are using in the essential occasions only. So the damages to the environment and humans are minimal.

Site preparation and forest plantation establishment in different geographical zones

Abstract of a Presentation conducted by

Gayan Udugama

Department of Forestry and Environmental Science, 

University of Sri Jayewardenepura, Sri Lanka

A written scheme of management aiming at continuity of policy and action and controlling the treatment is known as a Forest Management Plan. Under any plantations establishment survey and demarcation, site preparation, planting, irrigation, weeding, fertilizing, pruning, thinning, and regeneration felling are the main steps to be followed.

Survey and demarcation of boundaries is carried out generally using chain and compass survey or modernly using GPS technology. Before moving towards site preparation and planting operations, the buffer zones are identified and forest management layout will be prepared which includes location and shape of the forest plantation, road network plan, location of waterways, subdivision for fire breaks, access, spacing and mapping.

Site preparation is done to create favorable growing conditions for seeds and seedlings, and to facilitate tree planting operations. This will reduce the competition of unwanted vegetation in order to increase the survival and growth rate of the desired trees, remove slash and logging debris if the site has been harvested, and to improve water retention and provide optimal soil conditions to desired plants. The decisions taken here will depend on several factors such as existing vegetative cover, site terrain, purpose of plantation, species to be planted, soil conditions and economics.

In Sri lanka, abandoned chena lands/ vegetable lands, shrub lands and rubber uprooted lands are the common lands available for establishing forest plantation. Further such lands can be divided into three categories based on the geographic nature. They are namely flat areas, slopes and ridges. Therefore site preparation and planting operation will differ with the terrain. Generally in high slope areas forest plantation establishment is not carried out as the land is vulnerable to erosion and the operations are costly. Final decisions on the site preparation and planting will rely on the economics.

Vegetation clearance is the first step in site preparation where manual, mechanical, burning and chemical methods are used. In slopes and ridges mostly manual methods are preferred but in flat terrain mechanical and manual methods are being used. Burning is not allowed if the plantation need to be certified. Ploughing, subsoiling, pre-planting harrowing, planting pits and terracing is carried out after the vegetation is cleared.

Spacing of plantation will depend on objective of the planter and basically on several factors such as species, thinning operations, whether it’s an intercrop or a monoculture, etc. In slopes and ridges planting is carried out along the contours as a protective measure where in flat terrain any conventional planting layout suitable for land can be used.

Protection measures need to be undertaken for fire risk, pest and disease risk and for the risk of soil erosion and landslides.