My research interest is in community ecology and in looking at the factors that determine species success and diversity. Recently, most of my work has been in two very different systems: the invertebrate communities found in the water-filled leaves of pitcher plants and the ever changing mosaic of vegetation found on St. George Island, a typical microtidal barrier island.

Metacommunities in the pitcher plant, Sarracenia purpurea

In the last 15 years, ecologists have recognized that population and community patterns are determined by both the local species interactions, as well as larger patterns of migration and extinction occuring across larger heterogeneous regions. This work was built on earlier ideas about patch dynamics and migration, and has recently led to newer theory and experiments brought together under a loose theory of "metacommunities."

We have been testing a number of recent theories about community patterns across metacommunities, as well as developing some theory of our own. This work has taken advantage of the unique natural microcosms found in the water-filled leaves of the purple pitcher plant, Sarracenia purpurea. This leaves of this carnivorous plant attract insects that drown in leaves, ultimately providing nutrients for the plant. However, these prey insects also serve as the basis for a community in the leaves. Bacteria break down the insects, while serving as a resource for protozoa, rotifers, and mites. These bacteriovores are in turn consumed by the larvae of a specialist mosquito, Wyeomyia smithii.

Our current work in this system has been in two areas, both supported through grants from the National Science Foundation. First, we are testing earlier theory we published on how the importance of migration in metacommunities depends on the heterogeneity among local communities with a large region. We have just completed a series of experiments in which we manipulated both the migration rates and the among-leaf heterogeneity; much of the spring of 2008 will be spent analyzing these data.

Second, we are very interested in the evolutionary processes that occur with this community, especially as they relate to species diversity. These communities provide a natural system in which to follow the evolution of competing species. The evolution of competitors has been of long-standing interest in ecology and evolutionary biology; this interest has again come to the forefront due to questions about evolution of niche-partitioning vs. equivalence and nuetral theory.

Long-term Vegetation Dynamics on a Local Barrier Island, St. George

Barrier island provide very harsh environments for plants, as they are highly disturbed with soils that are often saline, nutrient poor, and subject to extremes in water availability. These habitats are quite important for ecological and economic reasons. They support a number of unique plant species, while serving as breeding areas for a number of birds and marine organisms. Barrier islands also serve as important buffers that protect more inland areas from both normal wave-action and storms. Finally, they are also serve as a coastal "canary in the mine" for observing and understanding the effects of global climate change related to storms and sea-level rise.

We are involved in two projects on St. George Island, appoximately 60 miles SW of Tallahassee. First, we initiated a long-term study of the vegetation dynamics on the island in 1998. An annual census is conducted each fall, along with other studies to periodically monitor dune dynamics and characteristics. Second, we are now using this long-term database to inform dune restoration. We have identified 6 six species that appear to either withstand storms or grow back quickly after storms. With funding from the U.S. Fish and Wildlife service, we are now initiating small restoration projects on St. George to test the efficacy of these species for restoration and conservation.

If are interested in further information about either of these topics, please contact T. Miller. We are happy to speak to local groups or to work with K-12 classes on ecology concepts related to either project.