Research Topics

Indirect Effects of Environmental Impacts.  Studying indirect effects of environmental impacts, such as species extinctions and introductions, changes in productivity, and changes in disturbance regime, on complex ecosystems.





Interaction Strengths.  Identifying observational and experimental approaches that predict the strength of species interactions in natural communities.  Parameterizing dynamic models of food webs.




Transition-based Models of Multi-species Communities. Parameterizing and experimentally testing models such as extensions of the Neutral Theory of Biodiversity, Markov chain models and spatially-explicit cellular automata models.




Global Change Impacts on Ecological Networks. Documenting the dynamics of ocean pH (ocean acidification) in response to increasing atmospheric CO2 concentrations and other physical and biological drivers, and predicting its effects on webs of interacting species in coastal ecosystems.  See movie clip of this research.



Extinction Risk.  Exploring experimentally the importance of genetic and demographic factors on extinction risk in small populations.  Population viability.




River Food Web Ecology. Studying whole-ecosystem response to large-scale impacts or management programs derived by focusing on single species, particularly in streams in Costa Rica and salmon-bearing rivers of western North America.



Ecology and Evolution of Invasive Species.  Species impacts in native and introduced habitats, character displacement, and life history change following invasion by House Finches and other species.