Sustainable Forest Management for Mixed-Dipterocarp Forests: A Case Study in Southwest Sri Lanka

Abstract

Mixed dipterocarp forests (MDF) were one of the most timber productive forests in the world. The forest region is named after the dominant canopy tree family Dipterocarpaceae within which two major genera (Dipterocarpus, Shorea) usually represent a disproportionate amount of the basal area. Compared with Latin America and Africa, MDF have much higher standing volumes of merchantable timber per hectare, but they were also the first to be over exploited and degraded (1970-ongoing). Most are now restricted to upland regions and require various restorative techniques if they are to be successfully managed. This study describes the silviculture of a financially viable management regime for southwest Sri Lanka. Our studies demonstrate that managing MDF for a combination of timber and enrichment plantings of nontimber forest products (NTFP) can be comparable to the most competitive adjacent land use – tea plantations. By managing for NTFP and timber, forest managers have new opportunities to solve the old problems of high-grading and land-use conversion. In addition, payments for ecosystems services that include water quality and yield, and credits for carbon would double forest value when compared with other competing land use values.