Vertebrates perform key roles in ecosystem processes via trophic interactions with plants and insects, but the response of these interactions to environmental change is difficult to quantify in complex systems, such as tropical forests. Here, we use the functional trait structure of Amazonian forest bird assemblages to explore the impacts of land-cover change on two ecosystem processes: seed dispersal and insect predation. We show that trait structure in assemblages of frugivorous and insectivorous birds remained stable after primary forests were subjected to logging and fire events, but that further intensification of human land use substantially reduced the functional diversity and dispersion of traits, and resulted in communities that occupied a different region of trait space. These effects were only partially reversed in regenerating secondary forests. Our findings suggest that local extinctions caused by the loss and degradation of tropical forest are non-random with respect to functional traits, thus disrupting the network of trophic interactions regulating seed dispersal by forest birds and herbivory by insects, with important implications for the structure and resilience of human-modified tropical forests. Furthermore, our results illustrate how quantitative functional traits for specific guilds can provide a range of metrics for estimating the contribution of biodiversity to ecosystem processes, and the response of such processes to land-cover change.
|Journal||Proceedings of the Royal Society B: Biological Sciences|
|Publication status||Published - 14 Dec 2016|
Bibliographical noteFunding Information:
This research was supported by Instituto Nacional de Ci?ncia e Tecnologia (CNPq), Empresa Brasileira de Pesquisa Agropecuaria (Embrapa), The Nature Conservancy, as well as grants from the Darwin Initiative (17-023) and Natural Environment Research Council (NE/F01614X/1, NE/G000816/1, NE/I028068/1, NE/K016431/1).
© 2016 The Author(s) Published by the Royal Society. All rights reserved.
Copyright 2017 Elsevier B.V., All rights reserved.
- Biotic interactions
- Ecosystem processes
- Land-use change
- Seed dispersal