Ecological stability across scales

Abstract

One of the greatest challenges facing ecologists is how to detect and predict species and community responses to disturbance against a background of concurrent and potentially interacting environmental, biotic and anthropogenic pressures. A continually growing human population and increased urbanization of wild habitats creates a shift in population dynamics with intensified disturbances. In order to understand how communities at different scales of organization will respond to these changes in their environment it is vital that we understand the components that contribute to their structure and stability. I use a combination of manipulative experiments in the field, outdoor mesocosms and laboratory microcosms to examine the structure and stability of communities of differing trophic complexity and intraspecific variability undergoing disturbance. My results highlight the role of both environmental and biotic context as key, but underestimated, factors in moderating the stability of biological communities. Moreover, they show that intraspecific genetic variability and microevolution can be as important as strong trophic interactions in determining community dynamics. These findings have important implications for our ability to assess and predict ecosystem dynamics in the presence of anthropogenic and environmental stressors.