Micro-scale restoration: A 25-year history of a southern Illinois barrens

We studied vegetation change of a remnant barrens in southern Illinois over twenty-five years. The study area was periodically burned between 1969 and 1993, but fire was excluded for a 16-year period (1974-1989). During the s tudy, the barrens supported a mixture of species whose preferred habitats r anged from prairie and open woodlands to closed forest communities. The her baceous vegetation may be on a trajectory characterized by increasing domin ance of woodland species and declining prairie species. Fire management tem porarily reversed this trend, but it continued once::fire was excluded. Rei ntroduction of prescribed burning in 1990-1993 altered the vegetation traje ctory but not back toward a species composition comparable to that present on the site before cessation of fire management after 1973. Following inter ruption of prescribed burning, tree basal area more than doubled, and densi ty showed a 67% increase between premanagement conditions in 1968 and 1988. Salix humilis (prairie willow) density had significant negative correlatio ns with tree density and basal area. However, there was no consistency in r esponse of shrub species on the site to the varied site conditions over tim e. Fire management on the site may not recover the historic barrens that oc curred on the site. Nevertheless, consistent fire management will drive veg etation changes toward increasing abundance of prairie and open woodland sp ecies that would otherwise be lost without burning.