A financial analysis of rain forest silviculture in southwestern Sri Lanka

We examine the financial aspects of three silvicultural systems to encourag e the sustainability of valuable hardwood species in mixed-dipterocarp fore sts of southwest Sri Lanka. We compare the net present value (NPV) of the c urrent forest management approach (diameter limit harvests) with shelterwoo d harvests that promote light hardwood timber species. In this analysis, we also consider the potential of enrichment planting various precious timber (Diospyros quaesita - calamander), and non-timber forest product (NTFP) sp ecies (Caryota urens - fishtail palm; Elettaria cardamomum var. major carda mom; Calamus zeylanicus - rattan) in conjunction with timber harvests. Two real (inflation adjusted) discount rates were used, 4 and 6%, respectively. Results show that when real discount rates are low (4%), and advance regen eration is present, NPV is highest for the one-cut shelterwood US ($9983 ha (-1)). At a high discount rate (6%), reflecting the current short-term conc ession system and unstable rights to harvest, and where no advance regenera tion was present, the diameter limit system (US $7173 ha(-1)) was the optim um. On sites with advanced regeneration, the one-cut shelterwood system is clearly preferable. For all but rattan, shelterwood treatments provide high er NPVs for NTFPs than diameter limit cuttings primarily because of the hig her light regimes and more growing space made available early in the rotati on. The value for tea cultivation (US $26,000 ha(-1)) far exceeds the value of managing these lands for timber alone, explaining the dramatic expansio n in tea plantations on private lands. However, our results suggest that ma naging these lands for a combination of timber and enrichment plantings of NTFPs (US $23,000 ha(-1)) can be comparable to tea plantations. By managing for NTFPs and timber, forest managers have new opportunities to solve the old problems of high-grading and land-use conversion. (C) 2001 Elsevier Sci ence B.V. All rights reserved.