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The Effect of Fire Reintroduction on Endemic and Rare Plants of a Southeastern Glade Ecosystem


Address correspondence to R. S. Duncan, email


Open habitats dominated by herbaceous plants on thin, rocky soils occur within the forests of eastern North America. Although these habitats vary in origin, structure, geology, and species composition, all contribute greatly to regional biodiversity by harboring endemic and/or rare plants. Little is known about how disturbances affect plant populations in these ecosystems. Fire once was a frequent natural disturbance in the Ketona dolomite glades of Alabama, an ecosystem harboring eight endemic taxa and numerous other species of conservation concern. We designed an experiment to determine how the reintroduction of fire into the glades and surrounding longleaf pine forests affects populations of rare glade plant species. Experimental and control plots were established within the glades. Experimental plots were burned in April 2004, and all plots were surveyed during two subsequent growing seasons (2004 and 2005). Populations of three of 14 species of conservation concern declined significantly after the initial fire but recovered the next year. Among other herbaceous species, only five and two differed in population size in 2004 and 2005, respectively. In 2004, more species were more abundant in control than burned plots, but this difference was not detected in 2005. Multivariate community-level analyses of species presence–absence suggested that the effects of fire were negligible by the 2005 survey. Populations of young trees that had invaded the glades declined dramatically as a result of treatment fires. These results suggest that the reintroduction of fire will not harm glade species and may help prevent encroachment of the surrounding forest.