My research focuses on plant community ecology and such related fields as plant geography, conservation biology, bioinformatics and plant population ecology. One commonality among members of our group is a very strong interest in field ecology and botany. The types of research interests represented among my research students cover a broad range of areas. To illustrate, I briefly summarize below a number of our current projects. I intend these to be viewed as examples; I am rather open-minded about what a student working with me might undertake for his or her graduate research. For a more comprehensive list of past and present student research projects, consult the UNC Plant Ecology Lab homepage. [Click for a current list of funded research projects.]

1. Secondary succession and forest dynamics on the Carolina Piedmont -- In this study we are trying to explain successional changes in community and ecosystem attributes as resulting from the population dynamics of the dominant tree species. For part of this project we use permanent study plots, many of which have been repeatedly sampled since the early 1930s. One part we are just completing is a study of tree seedling demography where we ask which seedlings ultimately enter the canopy and when those successful individuals become established. The large archive of long-term demographic data developed as part of this project provides numerous research opportunities. Hurricane Fran, which passed through here in 1996, caused significant tree mortality in our permanent plots and we are currently examining the impact of this unexpected event. For more detail, you may read key portions of our Proposal to the National Science Foundation for the grant that currently supports this work.

2. EcoInformatics: databases for vegetation plots and organism names -- I am currently directing a project centered at the National Center for Ecological Analysis and Synthesis in Santa Barbara with the objective of developing a database system for the US National Vegetation Classification. Components include a national vegetation plots database to serve as the data on which the national classification will be based, a taxonomic database that contains both species concepts and names so as to resolve ambiguities implicit in contemporary plant nomenclature, and a vegetation classification database module. I anticipate that VegBank and its massive quantities of co-occurrence data and linked environmental data will open up vast new possibilities for the grown of community ecology. For more detail, you may read key portions of our Proposal to the National Science Foundation for the grant that currently supports this work, or consult our project website at www.vegbank.org. The component of this project related to semantic mediation of names attached to organisms and communities is further supported as part of a large, multi-institutional NSF-ITR grant [see Summary or Proposal, or the SEEK project website]. A parallel activity has been to establish an EcoInformatics Working Group within the International Association for Vegetation Science with an initial goal of establishing international standards for exchange of plot data..

3. The dynamics of flood plain vegetation of coastal plain rivers -– In collaboration with Phil Townsend (Univ. MD CES) and several other colleagues, I am examining the long-term consequences of post-colonial sediment deposition, subsequent sediment movement, up-stream impoundments and water flow regulation on the composition and long-term dynamics of Southeastern floodplain forests. The Roanoke River of northeastern NC is of special interest and the primary focus of our work because of the large area of natural vegetation and the recent acquisition of much of the land by conservation interests. Geomorphologists have documented the general impacts of human activities on floodplain geomorphology, but rarely has such information been integrated by ecologists into landscape-scale analyses of the dynamics of floodplain ecosystems. The occurrence and significance to riparian ecology of widespread changes in sedimentation and erosion are largely unreported. We hypothesize that alteration of geomorphology greatly impacts the terrestrial ecology of riparian systems, and consequently that geomorphologic modification driven by changes in sediment deposition and transport patterns should be incorporated into studies of riparian systems. In this research, we plan to develop a general model of the implications of altered sedimentation patterns for floodplain ecosystems. For more detail, you may read key portions of our Proposal to the National Science Foundation for the grant that currently supports this work.

4. Vegetation of the Carolinas -– In collaboration with colleagues at several neighboring institutions, I am attempting to document the natural vegetation of the Carolinas and understand how that vegetation pattern maps onto landscape and how it has been influenced by underlying environmental factors and historical events. Conservation planning, land management, and documentation of ecological research all require a detailed understanding of the distribution of vegetation across the landscape. Toward this end we created The Carolina Vegetation Survey (CVS), a collaborative research program with the general goal of characterizing the vegetation of North Carolina and adjacent states. Participants represent academic, agency, NGO, and private groups and interests. Since 1988 the Carolina Vegetation Survey has organized annual vegetation sampling events as part of an on-going collaboration with the North Carolina Natural Heritage Program, The Nature Conservancy and the U.S. Forest Service aimed at description and classification of the natural vegetation of the state. For more details, consult the Carolina Vegetation Survey Website.

5. Fire-dependent vegetation of the Southeastern coastal plain -- Fire-dependent pineland vegetation once dominated the uplands of the Southeastern Coastal Plain from southern Virginia south to the tip of Florida and west to eastern Texas. Despite a relatively simple physiognomy, this ecosystem type is one of the most diverse and endemic-rich in the United States. The natural communities that occupied this landscape, as well as many of the plants and animals that inhabited them, are now rapidly disappearing. In this work we are first documenting the composition of the original, now almost vanished fire-dependent longleaf pine vegetation of the Southeastern coastal plain and how it varies with site conditions. In the second part, we are using gradient models to predict the original vegetation from site conditions. In short, we are attempting to construct a template for restoration efforts. One goal is a synthetic volume that summarizes our knowledge of this ecosystem. For more detail, you may read key portions of our Proposal to the Florida Nongame Wildlife Program for the grant that currently supports this work.

6. Mechanisms of co-existence in species-rich grasslands -– In a collaboration with colleagues in Uppsala (Sweden) and Utrecht (The Netherlands), I have undertaken an experimental study in which we attempt to test the relative importance of proposed mechanisms for the maintenance of plant diversity in species-rich grasslands (i.e., those with 40 species of vascular plants per square meter, among the most diverse communities in the world at this scale of observation). To assure the generality of our results, the experiments are replicated in species-rich grasslands in coastal plain savannas in North Carolina and Mississippi, chalk grasslands in Holland, and alvar vegetation in Sweden.