Research

I am interested in how microbial communities influence multispecies interactions, often between plants and insects. Below are some of the directions of my current research. For specific research interests of graduate students and postdocs, see Lab Members page.

How do microbes influence host phenotype and ecological interactions?

Study system: Nectar-inhabiting microbes

Yeasts and bacteria are common inhabitants of flowers, and can attain high densities in floral nectar. I am interested how (and when) these microbes influence plants and pollinators, the mechanisms involved, and evolutionary ecology of these interactions. In the plant species Mimulus aurantiacus, we have found that bacteria and yeasts can influence pollinator visitation, via changes in nectar chemistry, including secondary metabolites in nectar.

With John Beck and Caitlin Rering at USDA-ARS Gainsville, I am examining the influence of nectar-inhabiting microorganisms on pollinator preference through their contribution to floral volatile organic compounds.

Apis mellifera foraging on experimental nectar

Apis mellifera foraging on artificial nectar

Study system: Below-aboveground interactions in agroecosystems

All plants associate with fungi and bacteria belowground, and agricultural practices influence belowground microbial communities. I am interested in how fungal and bacterial communities change in response to different management practices, and how these changes influence plant-microbe interactions, plant phenotype, and plant-insect interactions.

In tomato, we are examining the influence of agricultural management strategies on rhizosphere microbial community structure and plant defense, with Amelie Gaudin, Clare Casteel and Christian Nansen.

Community ecology of plant-associated microbial communities

What mechanisms shape the structure and function of microbial communities associated with plants? How do can we use assembly mechanisms to better understand function, including effects on insect herbivores and pollinators?

Study system: Nectar-inhabiting microbes

Our current work at Stebbins Cold Canyon Reserve and the Laidlaw Honey Bee Research Facility /Haven examines the factors that structure microbial community composition in floral nectar.

Nectar chemistry

I am interested in intra and interspecific variation in nectar chemistry, and how ecological interactions influence different components of nectar chemistry, and the effects of this variation on plant reproduction and floral visitor behavior and performance.