Research Interests

For about a decade, I conducted experimental and natural gradient field research on how climate change and microclimate impact and interact with vegetation dynamics and biogeochemistry in chaparral and subalpine meadow ecosystems. Over the last few years, I have shifted into theoretical and computational ecology to elucidate and explain general patterns of ecosystem structure and function, focusing on networks of predator-prey interactions expressed as complex food webs.  I am using this framework to explore how trophic structure and dynamics interact to promote ecosystem robustness to perturbations such as biodiversity loss and invasions, with broader implications for stability of other types of biotic and abiotic networks. In addition to working with contemporary food webs, I am coordinating an interdisciplinary effort between ecologists and paleobiologists to construct and analyze detailed "paleofoodwebs." We are using these food webs, which extend back more than 500 million years before present, to look at the evolution of ecosystem structure through deep time. We hope to encourage the development of rigorous, quantitative paleoecological community studies by other researchers.  I am also collaborating with archaeologists to look at how Aleuts interacted with the complex, interconnected marine, intertidal, terrestrial, and freshwater ecosystems of the Sanak Island Archipelago (Aluetian Islands, Alaska) over the last 6,000 years.  My interest in facilitating widespread scientific communication and data sharing also motivated my involvement in two interdisciplinary National Science Foundation funded projects, "Webs on the Web: Internet Database, Analysis and Visualization of Ecological Networks" (WoW), and "Semantic Prototypes in Research Ecoinformatics" (SPiRE).  My colleagues and I are developing a WWW knowledge base with integrated ecoinformatics and semantic web tools for biocomplexity research and education relating to the structure and dynamics of empirical and model food webs and other ecological networks.