TRADE-OFFS BETWEEN RUBBER PRODUCTION AND MAINTENANCE OF DIVERSITY - THE STRUCTURE OF RUBBER GARDENS IN WEST KALIMANTAN, INDONESIA

The goal of this study was to assess the potential of small-holder rub ber cultivation in agroforestry gardens to fulfill simultaneously the goals of conservation and sustainable rural development. I examined th e structure and species composition of trees in 11 rubber gardens in W est Kalimantan, Indonesia, using a single 0.10 ha plot per garden. Alt hough 41 distinct morphotypes were encountered, rubber (Hevea brasilie nsis) dominated the sample of 370 trees. Richness within plots varied (3-15 morphotypes), as did the predominance of rubber (24-97% of all b asal area, 24-91% of all individuals). The importance of rubber within a garden was significantly negatively correlated with the number of m orphotypes present. This result suggests that tree diversity may limit potential productivity of rubber gardens. Thus, small-holders may not be willing to maintain diversity at the scale of a single garden. Alt hough species-accumulation curves indicate that substantial tree diver sity may exist across all rubber holdings, diversity is likely to be l ost from the system if individual owners reduce species richness in th eir gardens. Rubber agroforestry as currently practiced in West Kalima ntan is not an ideal model for matching rural development needs with t he achievement of conservation goals. Other models, such as tengkawang - and durian-based fruit gardens, do exist in Kalimantan and elsewhere , and should be evaluated for incorporation into policy and developmen t strategies.