Woody plant succession is a particular conservation management concern in Carolina bays because many rare plant species are most abundant, or limited to, herbaceous communities with little or no tree cover. In a Carolina bay in Maryland, effects of woody plant succession on plant species abundance and community characteristics were studied during 1987-99. The dominant species, Rhexia virginica L., decreased in cover by 89% in the depression-meadow community and by 81% in the contiguous expanding zone of seedlings of persimmon (Diospyros virginiana L.), red maple (Acer rubrum L.), and sweet gum (Liquidambar styraciflua L.). Woody plant expansion was probably related to a 1986-88 drought. Since R. virginica declined significantly in unshaded and partially shaded zones, irradiance level apparently does not solely explain its decrease in abundance; field observations warrant testing for allelochemic substances passively leached from tree species. Fimbristylis autumnalis (L.) Roemer & Schultes increased in both depression-meadow and woody seedling zones by a factor of 24 and 25, respectively, and it became a co-dominant by 1992. Manual removal of successional woody species and prescribed burning during episodic droughts may be critical to the restoration and maintenance of species richness in the depression-meadow community.