Community disassembly rules and the erosion of ecosystem functions in fragmented landscapes

My proposed research is designed to assess the causes and consequences of species responses to deforestation. To address this goal, I will analyse an extensive existing dataset containing information on more than 10,000 individuals of bird and small mammal species captured with a standardised protocol in 65 forest patches of different sizes and connectivity located in six landscapes of the imperilled Atlantic Forest of São Paulo, Brazil (three continuous landscapes with over 90% forest cover and three fragmented landscapes with 10, 30 and 50% forest cover respectively). To understand the causes of species responses, I will analyse this dataset to determine: (i) which mechanisms underlie community changes and what drives community dynamics in fragmented landscapes. To address this question, I will use a novel theoretical framework in which the biological bases responsible for structuring communities are tested against neutral models; these results will allow me to assess the extent to which communities deviate from neutrality and to identify which traits are the best predictors of species extinction. Hypotheses about community disassembly are virtually untested in fragmented landscapes, let alone the poorly studied Atlantic Forest, but have important implications for conservation biology. If species responses to deforestation are mainly due to stochastic processes, then any effort to predict the structure of future communities, and possibly prevent species extinction to deforestation, would be highly ineffective. Sequential species extinction following deforestation causes changes in the structure and composition of communities. Moreover, species differ in the ways by which they process resources, in their effects on the environment, and in how they interact with other species. Consequently, reductions to the number of species can decrease the number of ecosystem functions being performed (functional diversity).Thus, to understand the consequences of species responses to deforestation, I will assess (ii) how species extinction affects the number of ecosystem functions performed (functional diversity) and (iii) how the response traits that render species susceptible to deforestation might be correlated with the effect traits that determine their function in the ecosystem. The results from these analyses will allow me to identify (iv) which species are more important for keeping ecosystems functioning and should thus be the target of conservation strategies. I also aim to study (v) the interaction between species extinction thresholds and the decline of functional diversity in fragmented landscapes. Finally, by combining all this information it will be possible to estimate (vi) the minimum area requirements necessary to sustain a functional ecosystem. These questions will be tested with the use of analytical frameworks developed in several areas within biology, drawing together advances in phylogenetics, population biology, community ecology, landscape ecology, and multivariate statistics. Therefore, with this project I aim to advance the scientific understanding of the processes that govern community dynamics in fragmented landscapes and the consequences of landscape alteration for maintaining a functional ecosystem, and will generate solid predictions that can be used for building objective and accurate conservation strategies.