Tree species distributions across five habitats in a Bornean rain forest

Abstract. We examined the distribution of tree species across five habitats in 69 small plots within a single watershed of the Gunung Palung National Park, West Kalimantan, Indonesia (GPNP). The spatially complex distribution and close proxim-ity of habitats provided an opportunity to test habitat specificity of tree species across strong environmental gradients, in a situation where dispersal into ‘inappropriate ’ habitat should not be a rare event. Habitat had a weak influence on commu-nity structure, although species diversity was lower in the alluvium and peat habitats. Association tests based on two randomization models (spatially independent and explicit) were used to examine habitat distribution of 55 ‘common ’ and 142 ‘frequent ’ taxa. The general patterns were similar in the two models but the interpretation of specific patterns de-pended greatly on assumptions about dispersal ability.