Mutualists within Communities

Plants and AM fungi exist within a broad network of interactions that create ecological communities. Understanding how communities change in the presence, absence, and variation of mutualists informs us of the role of mutualists in communities. I use simple and complex plant-interaction chains to examine how the presence or absence of a species alters simple communities, and how those changes feed back to alter evolutionary trajectories of interactions.

AMF potential to alter plant-herbivore abundance over time
I created five models to describe how changes in plant quantity, quality, tolerance, and defense would lead to changes in plant and herbivore abundance over time (Bennett et al., 2006) (PDF). The assumptions of the models are supported by my empirical tests, and future research aims to further develop these theories by documenting changes in plant-herbivore interactions in the absence and presence of AMF over time in both greenhouse and field experiments.

AMF-Plant-Herbivore
Can we predict changes in a simple community by adding the outcomes of two interactions? In the case of AMF- plant-herbivore interactions, we would expect increased herbivore fitness on mycorrhizal hosts. I found that specialist herbivores experienced increased fitness on mycorrhizal hosts, but changes in plant defenses and tolerance with different fungal communities suggested that not all herbivores would benefit in the same manner (Bennett & Bever, 2007 (PDF), Bennett et al, 2009 (PDF)). Future research will test the generality of herbivore response to AMF infection, and how climate change may alter the ecology and evolution of AMF-plant-herbivore interactions.