Transições em uma comunidade de palmeiras ao longo de um gradiente topográfco de uma foresta inundável à terra firme na Amazônia oriental

Abstract

Palms show clear niche segregation patterns along topographic gradients in tropical forests, with some species associated to terra firme and others to seasonally flooded areas. Te aim of this study was to quantitatively describe the fine-scale spatial variation within a palm community, tracking the changes in species’ abundance along environmental gradients associated with a perennial stream the eastern Amazon. Te study of palm communities was based on 60 forest plots in which all adult palms were counted. We found a total of 566 palms in a community containing 11 species. Furthermore, we found a significant separation in the palm community between seasonally-flooded and terra firme forests. We found a gradient with various densities of the three most abundant palm species within the first 100 m away from the flooded area. Other species were located exclusively in the terra firme forest. Te abundance of the six most common species were distributed in relation to humidity gradients from floodplains to terra firme, with palm distribution from the most food-tolerant to the least food-tolerant palm species as follows: Euterpe oleracea, Attalea phalerata and Socratea exorrhiza (species with foodplain afnity), Astrocaryum gynacanthum, Astrocaryum aculeatum, Attalea maripa (species with terra frme afnity).