Harvest Scheduling and Replanting in Comjmercial Forestry

Presented by

Arundathi Koliyabandara

Harvest scheduling is a traditional exercise that has been carried out by forest land managers on public and private lands alike. Industrial forest management has generally been distinguished by a much higher rate of intensification than has been the case on public lands. Whereas public land management has characteristically balanced timber and non-commodity forest production. Industrial plantation establishment has been dominated by profit maximization and cost reduction through economies of scale. Forest companies are now facing the challenge of scheduling spatially specific timber management activities over time to achieve their traditional objectives and the new environmental goals.

A good operational harvest schedule will satisfy the customers’ orders from areas of forest while minimising transportation costs. Also, areas of the forest with high quality trees will be used to provide high quality (high value) logs while lower quality areas will fulfil low quality (low-value) demands, minimising the conversion of high quality trees into low-value logs. Operational harvest scheduling can be very difficult. Good operational harvest scheduling is an activity where large immediate financial gains can be found. This is in contrast to tactical planning where gains will be seen in two to three years, or strategic planning with gains realised thirty or more years in the future. The immediate gains of a good harvest schedule are listed below. Harvesting costs are reduced, harvesting productivity is increased, larger volumes of high quality logs are produced and transport costs are lowered. Harvesting is done by two means as thinning and clear cutting. The conducting silvicultural system and the economics and demand are important factors when scheduling the harvest. There are commonly using harvesting systems as clear cutting, shelter wood, selection and coppicing. Clear cutting is where all of the trees in a stand are removed. Clear cutting diseased or insect-infested area  is often necessary to protect healthy trees. Shelter wood System is designed to remove certain trees and establish new growth under the protection of an over story of foliage. Sufficient mature trees are left standing to shelter the site until new growth is well established. The using silvicultural system depends on the objective.If a site is maintained to get timber and to maintain aesthetics selection is used. Coppicing is used when fuel wood is gained. If the prime objective is to get timber, clear cut is the method which will be practised.

The rotation is also an important consideration in harvest scheduling. It helps in deciding when to harvest the stand. There are main rotations used in commercial forestry which can be stated as technical rotation, biological rotation, income generation rotation and etc. Technical rotation is suitable for providing timber, wood with specific dimensions. In biological rotation the maximum volume production is expected. The stand is harvested when maximum mean annual increment is reached. Income generation rotation is a monetary rotation where the harvesting is scheduled at the time where highest average income is gained.

Replanting of a harvested site is an important managerial activity which depends on on social, cultural, economic and environmental reasons. Use of the same species or different species is a choice made by the management. When replanting is carrying out proper silvicultural practices should be maintained to gain the final harvest such as nursery establishment and maintaining, establishment of pits for planting, spacing, block wise replanting ,weeding , fertilising, irrigation, thinning and pruning. Intercropping can be practised based on the objectives.

In Sri Lanka some upcountry Eucalyptus plantations are clear-felled and replanted with more suitable Eucalyptus species. Some selected mature Pinus plantations too are clear-felled and replaced with, Khaya, Hora, Eucalyptus and Mix species. Dry Zone Teak plantations are re established mainly with Teak in the second rotation. However in the areas where elephant damaged is high, Khaya was planted instead of Teak.

Carbon sequestration potential of a plantation will be an added benefit and when scheduling harvest the area leaving for conservation and proper practices of harvesting should be planned.

Establishment of an African mahogany Plantaiton by Green World Plantation Company

Abstract of the presentation of

Sonali Batuwatte

Khaya (Khaya senagalensis) is one of the most popular species in Sri Lanka. Management objective of the Green World Plantation Company is to optimise the land utilisation by growing commercially viable and environmentally sustainable trees. The company will increase its profits by providing better quality timber in required amounts. Vision is to “Become the Market Leaders in Khaya Wood Production in Sri Lanka” and Mission is “Production of high-value and high-quality timber on sustainable basis to relieve the pressure on our natural forests, practice commercial forestry by bringing in investors to invest in our plantations.”

Khaya senagalensis belongs to the Meliaceae family and it is native to Africa. It reputedly has the best surface finishing of all the African mahogany species. Khaya timber is highly valued because of its beautiful figurative grain and its rich reddish mahogany brown colour. It is a medium-sized tree which can grow up to 15–30 m in height and 1 m in diameter. It has a fast growth rates in dry and intermediate zones, tolerance to poor site quality and resistance to heavy weed competition, harsh conditions and diseases and pests (except borer). It is favored for furniture, high-class joinery, trim and boat building, railroad ties, flooring, turnery and decorative veneer.

For management prescriptions land selection, planting, protection, labour and staff and extraction can be mentioned. Under planting, seeds, land preparation, spacing, fertilising, weeding, watering, thinning, pruning, pests and diseases. A land of 50 ha in the Intermediate Zone in Kurunegala is selected by using & checking soil parameters. Land Demarcation is carried out by surveying and establishing boundaries. Land is divided in to 10 perch blocks in order to attract small scale investors. 800-1100 trees/ha will be planted with a spacing of 3m × 3m. Live fire belt will be established using Hana. Proper maintenance practices will be established including fertilizing up to 4 yrs and after the PCT with a mixture of N:P:K 9:13:9. Three commercial thinning are carried out at the ages of 11, 15 and 20 years. Creeper cutting is carried out from the 1st year while pruning carried out from 4^th year before and after the rainy season. Watering is done using drip irrigation up to 6 years, 4 l/day in the dry season. Harvesting will be done using clear felling at the age of 25 yrs. In its natural range, K. senagalensis can be severely attacked by shoot borers (Hypsiphylla robusta). Such attacks may result in misshapen trees with no timber value. Carbofuran can be used to minimize these attacks.

Challenges faced in establishing khaya plantations in Sri Lanka

Challenges faced by the Forest Department in establishing khaya plantations in Sri Lanka

Abstract of a seminar presentation

Benica Jayasekara

Khaya senegalensis is the scientific name for khaya, which belongs to the Family Meliaceae. It is commonly known as African mahogany or dry zone mahogany. It’s a fast growing tree species in dry conditions and grows up to 20-30m in height. Timber of khaya is hard, dense and reddish brown in colour.

Khaya is one of the major timber species used by the Forest Department in reforestation programs in dry and intermediate zones of Sri Lanka. It was introduced from Africa during 1960’s. However, most of the khaya plantations of Sri Lanka are less than 10 years old.

The reasons for the use of Khaya by the Forest Department is the high demand for timber, fast growth rates in dry and intermediate zones, tolerance to poor site quality and resistance to heavy weed competition, harsh conditions and diseases and pests (except borer). Moreover the rural community prefers khaya over teak because khaya is morphologically more similar to the native species in Sri Lanka. In addition to those, wild elephants do not damage khaya trees.

According to the Forest Department, khaya was selected as the best tree species for the dry zone. There are however, a few challenges faced by the Forest Department in establishment of khaya plantations. Expensive seeds, low seed viability, fertilization, weeding, multiple shoots, porcupine damage, black twig borer attack, red stem borer attack and the forest fires as examples.

Forest Department had taken remedial actions for these challenges and still they are doing further studies to improve the khaya plantations. Still the khaya plantations in Sri Lanka are less than 10 years and therefore the Forest Department might face more problems with the time, because the rotation age of khaya is 30 years and still the yield tables for this species has not been prepared.