Impacts of edge effects, fire, and climate change on vegetation composition and functional diversity across spatial scales in the Amazon rainforest

Abstract

Habitat loss and climate changes will shape the future of Amazonian ecosystems, with significant implications for the different facets of diversity. Climate models predict that the highest changes in temperature and reduction in precipitation, as well as longer dry seasons, will take place in Southeast Amazon (SEA) region. Besides environmental changes, this is the region where the Amazon Forest is more threatened by anthropic activities, including deforestation and defaunation. Local and regional experiments in SEA have detected directional changes in forest species composition, mainly associated with edge effects and fires, with significant changes in microclimate. Despite the ecological significance of these processes for biodiversity and ecosystem functions, few studies have quantified the large-scale impacts of edge effects, fire, and climate change on vegetation distribution. In this project, we will integrate information on how microclimate changes community composition at local-scales with habitat suitability models to predict potential vegetation and animal redistribution across the Amazon biome. We will also assess how edge effects, fires, and different climate change scenarios influence community composition, trait distribution, and the resistance and resilience of Amazon forests. Our predictions are as follows: (1) edge microclimate will act as a filter, excluding species beyond their tolerance limits, allowing us to estimate edge effect distances and test which plant traits are related to those filters; (2) burned areas will exhibit greater differences in potential species composition (grasses versus trees); (3) climate change will reduce habitat suitability for forest specialists while favoring generalist species with broader niches, with declining in the functional diversity; and (4) changes in vegetation will also alter environmental suitability for different animal groups (birds and mammals) reducing the available habitat for forest specialists and impacting the faunal composition and ecological functions across the region.