My research focuses on three areas:

The Origin of Species Revisited: Speciation Due to Ecological Factors
One area of my research focuses on the general question of how new species originate.
Many organisms are ecological specialists, utilizing specific foods, habitats, etc. Under certain circumstances, this specialization might lead to the origin of new species. The organism that my colleagues and I have examined to address this question is the goldenrod ball gallmaker (Eurosta solidaginis). This insect forms galls on goldenrod (Solidago altissima). These galls serve as housing and provide food to the insect. Population densities of the gallmaker can become quite high. This can lead to competition for shelter and food, which in turn could lead to adaptation to a new host plant. Natural enemies such as parasitoids and downy woodpeckers can also exert selection pressure to move to a new host. Once a part of a population moves to a new host, this new population may serve as the origin of a new species. It appears that Eurosta is undergoing ecological speciation: Populations have become established on another goldenrod species, Solidago gigantea. The populations on the two hosts, although morphologically indistinguishable, are genetically differentiated from one another.

Turning the (Dining) Tables: Carnivorous Plants
Usually, plants are the bottom of the food web and are eaten by insects and other animals. Some plants turn the tables and prey on animals. I’m also interested in the ecology of carnivorous plants. The pitcher plant (Sarracenia alata) occupies nutrient-poor bogs of Texas, Louisiana, and Mississippi. It captures insects in its trumpet-shaped leaves and digests them for the nutrients they contain. Characteristics such as size, nectar production, and the presence of nectar guides are related to prey attraction and capture. Ecological conditions such as shade and fire can affect these characteristics, which in turn affect insect capture. This, in turn, affects plant nutrition. But, as is often the case in nature, turnabout is fair play, and the carnivore becomes food. There are specialist insects that can circumvent the trapping mechanisms and use pitcher plants for food themselves.

The Endless Cycle of Nature: Nutrient Cycling in Ecosystems
In nature, elements are cycled through the various organisms that comprise the ecosystem. Both abiotic and biotic factors affect the rates at which elements cycle in an ecosystem. The interactions of plants and herbivores can lead to changes in the composition of plant tissues that in turn affects the rates at which these materials are recycled.