Biodiversity is being lost at an unprecedented rate. This makes it imperative to understand the mechanisms maintaining population persistence and species coexistence. I investigate coexistence mechanisms in both antagonistic (e.g. predator- prey, host-parasitoid) and mutualistic (e.g. plant-pollinator/seed disperser) communities. I study a host-multiparasitoid community in the coastal sage scrub in Santa Barbara Co., California, and develop a theoretical framework for investigating the assembly and persistence of mutualistic communities. I also work on a waterbird conservation project in Kenya.

Host-Parasitoid Interactions in Santa Barbara Co., CA

I investigate coexistence mechanisms in a natural host- parasitoid insect community. I first use a model parametrized with data from laboratory experiments to predict the host species’ population dynamics in a constant environment. I then quantify the temperature responses of life history traits and use an automated video system to investigate the host-parasitoid interactions. This research has implications for the conservation of biodiversity and biological control of agricultural and invasive pest species.

Click here for more information or visit Plant Bug Central

Assembly and Persistence of Mutualistic Communities

Mutualistic communities are predicted to be extinction-prone, but data show long-term persistence. The challenge for theory is to identify the mechanisms maintaining persistence. I develop a theoretical framework which predicts that competition for the benefits provided by mutualistic partners can promote persistence. I then investigate whether competition for benefits can promote the assembly of the more complex mutualistic communities observed in nature.                         Photo by Roy Johnson

Click here for more information