Management plan for African mahogany

Management plan for African mahogany (Khaya senegalensis)

Abstract of a seminar presentation

Based on a hypothetically formed plantation company

Supun Nigamuni

Khaya senegalensis was introduced to Sri Lanka about 30 years ago and in the past 10 years it has become one of the priority species for timber plantation establishment in the dry zone. Timber is highly valued because of its beautiful figurative grain and its rich reddish mahogany brown colour. It is favored for furniture, high-class joinery, trim and boat building, railroad ties, flooring, turnery and decorative veneer.

A hypothetical company in the name of Greenwood Plantation Services Ltd was selected. Management objectives of the company are production of high-value; high-quality timber on sustainable basis to relieve the pressure on our valuable rainforests, practice commercial forestry by bringing in investors to invest in our plantations, achieve butt logs at harvest approximately 6 m in length and 40-60cm DBHOB with minimal taper and knots in 25 years, maintain plantation volume productivity, of 15-20 m³/ha/y merchantable volume over bark. Company is also aiming at achieving FSC certification enabling it to reach overseas markets.

A marginal land in the Dry Zone of 50 ha in Wellawaya is selected by using indigenous knowledge & 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. Plots near the main roads or boundaries of the land and if there is a tank or natural scenery plots associated with that is kept by the company as a security. Main road of 20 ft, sub roads of 12 ft will also be demarcated. Land clearing, removing shrubs, clear debris is carried out in late September, holing & planting carried out in early October targeting the NE monsoon. 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 thinnings are carried out at the ages of 11yrs, 15yrs, 20yrs. Creeper cutting is carried out from the 1^st 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, 4l/day in the dry season. Harvesting will be done using clear felling at the age of 25 yrs. In its natural range, K. senegalensis 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.

At present harvest of 1 m³ of > 1.5m log in the local market is Rs. 13,830.00. Assuming 6% annual increase of Khaya lumber prices in 25 years it is projected to be Rs. 34,580.00. By doing a detail cost benefit analysis it is evident that the company will make an aggregate profit of Rs.1.4 billion in 25 yeas.