Agroforests combine farmer-planted trees with selective retention of trees from natural forest regeneration to provide vegetation that is enriched in useful species, at low cost of labour and input relative to ‘plantations’. The forest context in the landscape is the main source of tree germplasm and as such provides an ‘environmental service’ to the fa rmer. This service is poorly quantified and probably under-appreciated. This study compared tree diversity in seedling, sapling and tree stages in rubber agroforest (RAF) and natural forest in Jambi (Sumatra, Indonesia). The tree species in forest and RAF were classified based on seed dispersal types and IUCN red list. Intensity of RAF management by farmer was grouped. The data were analysed to clarify natural processes and farmer management in species turnover. Main conclusions are: 1) RAF and forest provide similar habitat, but RAF contains less species with known dependence on ectomycorrhiza, 2) Species richness and species accumulation curves for the seedling and sapling stages were similar between RAF and natural secondary forest, with under representation of large-seeded (autochorous) short-distance dispersal mode in RAF, 3) Major loss of tree diversity occurs in RAF between sapling and tree stage by selective culling, 4) Most trees retained in RAF have known use for local livelihoods and/or markets, 5) RAF plays some, but modest, role in survival of endangered tree species in the landscape, as evident from ‘red list’ trees of ‘critically endangered’ and ‘endangered’ species. We conclude that the forest matrix around rubber agroforests has so far provided the service of a continuous influx of a very diverse tree flora that includes many useful trees. With the rapid loss of natural forest from the landscape, this service is at risk and more pro-active tree recruitment by farmers will be necessary if they want to maintain agroforests with high diversity.
Année de publication
2009
Auteurs
Tata H L; Rasnovi S; Werger M J A; van Noordwijk, M.
Langue
English
Géographique
Indonesia
