Long-term change in the tree community of a tropical forest remnant surrounded by human-modified landscapes

Abstract

Previous studies have demonstrated that the tree community of small and isolated forest fragments show persisting structural and functional attributes characteristic of early-successional systems. Yet, the impacts of forest small size and isolation on several tree community attributes have not been comprehensively quantified in long-term studies. Here we analysed permanent plots over 17 years to investigate the recovery of community attributes in a small tropical forest remnant surrounded by human-modified landscapes in the endangered Brazilian Atlantic Forest. We conducted analyses on community species richness, functional diversity and composition, and aboveground biomass for the overall, adult and juvenile communities. The analysis of the demographic rates indicates a self-thinning phase (reduction in stem density and increase in basal area) characteristic of late-succession stages. In general, we found a reduction in the proportion of simple leaves along with a gradual increase in wood density mostly for the adult tree community and a significant increase in aboveground biomass throughout the years. Despite its reduced size, the fragment studied does not show clear trends of altered forest structure and functional composition dynamics through time. Yet, it holds aboveground biomass values comparable to large undisturbed rainforests, thus indicating that the ecological value of small forest fragments should not be neglected.