Species Composition, Species Diversity, and Ecosystem Processes: Understanding the Impacts of Global Change

Abstract

Invasions by exotic species, climate change, increased atmospheric CO2, deposition of N, habitat destruction and fragmentation, predator decimation, and many other anthropogenic perturbations to ecosystems can have both direct impacts on ecosystem processes and indirect effects mediated through changes in ecosystem composition and diversity. The work reviewed in this chapter suggests that the long-term effects of global change will depend on the changes in ecosystem composition and diversity that occur in response to global change. If this is so, the discipline of ecology faces its greatest challenge to date: to discover how to predict the effects of global change on ecosystem composition and diversity and how to predict the joint impacts of all these changes on a variety of ecosystem processes.