Shortleaf pine-bluestem restoration for red-cockaded woodpeckers in the Ouachita Mountains: Implications for other taxa
The more xeric south- and west-facing slopes of the Ouachita Mountains of west-central Arkansas once supported fire-maintained shortleaf pine (Pinus echinata) forests with a well-developed herbaceous understory. Fire suppression following the original harvest of these forests resulted in forests with increasingly abundant woody vegetation in the understory, midstory, and canopy, and a very suppressed herbaceous understory. Due largely to these habitat changes, red-cockaded woodpecker (Picoides borealis) populations declined to extremely low levels by the 1990s. Ouachita National Forest managers increased the emphasis on prescribed burning and thinning in the late 1970s and initiated landscape-level restoration of shortleaf pine-bluestem (Schizachyrium spp. and Andropogon spp.) communities in 1996, in part to support recovery of the endangered red-cockaded woodpecker. Restoration involves thinning the pine and hardwood overstory, mechanical removal of midstory pines and hardwoods, and prescribed burning on approximately a 3-year return interval. This management (which will eventually encompass over 48,000 ha) has been very successful in returning large areas to a condition similar to historical photographs of original shortleaf pine forests. Restoration results in a more open, pine-dominated overstory and an increase in herbaceous vegetation compared to untreated control areas. The abundance of nectar resources was significantly higher in treated areas compared to controls, peaking in the first growing season following burning and declining thereafter. Overall abundance and species richness of butterflies, amphibians, reptiles, mammals, and birds were generally greater in restored areas compared to controls. Many species of conservation concern, including Diana fritillary (Speyeria diana), red-cockaded woodpecker, northern bobwhite (Colinus virginianus), prairie warbler (Dendroica discolor), brown-headed nuthatch (Sitta pusilla), and Bachman's sparrow (Aimophila aestivalis), also responded positively to restoration. Of the taxonomic groups studied, few maintained higher abundances in the control areas. Overall, regional abundance and natural patterns of diversity of the examined taxa will be enhanced with rrjswration of shortleaf pine-bluestem communities on appropriate sites in the Ouachita Mountains.