Since the 1970s, the Biological Dynamics of Forest Fragments Project, near Manaus in Amazonian Brazil, has provided a research setting that includes small patches of rainforest, active and abandoned agricultural areas, and a large expanse of undisturbed rainforest. This project builds on a 20-year study of avian population dynamics in forest fragments that has focused on how changes to the landscape have affected bird abundance, distribution, and social organization. Over the next five years, US and Brazilian researchers will examine whether or not forest birds can survive and reproduce as well in fragments and abandoned deforested areas as they do in undisturbed forest. Using passive capture, mark, and release of birds, the investigators will quantify survival, breeding activity, transience, and age-specific abundance. These data will permit the most detailed assessment to date of the value of secondary growth and fragments to a large number of understory birds. Whole-community techniques will also be used to assess species richness, biomass, and social interactions across plots.
Tropical rainforests support a disproportionately high number of species. Increasing human populations and agricultural expansion in the tropics fuel deforestation, although many deforested areas are subsequently abandoned. Because of this cycle of cutting and abandonment, the long-term persistence of many tropical species will depend on their capacity to use forest fragments and regrowth forest. Results from this study will help to determine the ability of fragments and secondary growth to maintain biodiversity. The project will continue to build capacity of both Brazilian and US students through their direct involvement in the research and through the development of new field and educational materials.
