My principal research interest is the description, classification, and study of environmental relationships of natural vegetation, with special emphases on conservation ecology and biodiversity. This broad interest has taken many directions, including studies of distributional consequences of plant biochemical differences, plant water relations, and plant mineral nutrition. Much of my work involves use of mathematical/statistical approaches to analysis of community data (numerical classification and gradient analysis). My dissertation research was a comparison of vegetation patterns on limestone and more acidic rocks in the mountains of southeastern Arizona, and I continue to have an interest in contrasts in vegetation found on varied substrates. A large part of my current research effort is focused on characterization of vegetation in the mountain and coastal plain regions of North Carolina. I am a co-founder and principal investigator of the Carolina Vegetation Survey, which has as its goal the thorough characterization of the natural vegetation of North and South Carolina using quantitative data on vegetation and environment from a statewide network of permanent plots.

Other research interests include population biology, competitive interactions, and molecular ecology of plants. I have worked frequently in the area of applied research and collaborate frequently with faculty in other departments at NC State University, such as Forestry and Horticulture. Through efforts of the Carolina Vegetation Survey, I have assisted state and federal agencies interested in restoration of degraded ecosystems. Other applied projects have included development of criteria for the use of vegetation in the designation of wetlands, studies of the effects of commercial logging and site preparation practices on regrowth of natural vegetation, and analysis of the impacts of pinestraw raking on natural vegetation in longleaf pine forests.