Dissertation Research: Regulation of Species Diversity by Assembly History in Ecological Communities

University Of Tennessee Knoxville, Knoxville TN

Investigators

Abstract

Spatial scale poses a fundamental problem in understanding species diversity because mechanisms creating variation in diversity change with scale. Ecological communities are structured over time as well as patterned across space. Community assembly, how species join communities over time, not only poses another problem, but also is responsible for observed spatial patterns. It is not well known how species diversity, community assembly, and spatial scale relate. This project examines three factors that may determine the degree to which assembly contributes to diversity at different spatial scales. The number of species in the regional species pool, the amount of nutrients available to communities, and the number of disturbance types imposed on communities may all play important roles. Hypotheses addressing these factors will be developed through computer simulations and tested through laboratory experiments using bacteria, protists, and rotifers. These approaches, unlike most field studies, ensure rigorous control over invasion sequence and environmental conditions and monitor community dynamics over many generations. Overall, this project will provide an assembly- based model explaining species diversity. Adding temporal dynamics of community assembly to our perspective will enable ecologists to better understand how and when spatial scale is critical in assessing the regulation of species diversity.