ENRICHMENT PLANTING IN SELECTIVELY LOGGED RAIN-FOREST - A COMBINED ECOLOGICAL AND ECONOMIC-ANALYSIS

We demonstrate how research on innovative agroforestry systems, incorp orating new species and management approaches, can benefit from prelim inary financial appraisals that include both economic and ecological v ariables in quantitative cost-benefit models. Model results provide vi tal information for planning further research, and thus increase the l ikelihood of finding practical solutions to urgent resource management problems within reasonable funding and time constraints. As a case st udy, we evaluate the potential of enrichment plantings of three native fruit-producing genera in selectively logged rain forests of Kalimant an, Indonesia. The models use preliminary estimates of 8 ecological pa rameters (e.g., survival, growth rate, fruit production) and 11 econom ic parameters (e.g., planting and harvesting costs, market prices) to predict net present value (NPV) over a variety of project durations an d discount rates. Sensitivity analyses examine the effect of changes i n input parameters. The genera were chosen (1) for ecological compleme ntarity in the use of light resources and (2) to produce fruit at time s when commonly harvested species are unavailable in markets. Dialium spp. are canopy trees that produce timber and a relatively nonperishab le fruit; Willughbeia spp. are fast-growing lianas that produce fruit; Garcinia spp. are understory fruit trees. Sensitivity analyses indica te that all three genera have potential for substantial positive NPV, and that NPV projections depend heavily upon fruit price, fruit produc tion, age of first reproduction, juvenile survivorship, and harvesting and marketing costs. In addition, these analyses demonstrate that pre liminary, combined ecological-economic analysis can guide the selectio n of species and research strategies for experimental trials.