Shortleaf Pine ecosystem restoration: impacts on soils and woody debris in the Ouachita mountains of the southern United States
A number of organizations and government agencies have been involved with restoration of overstocked shortleaf pine-hardwood stands to shortleaf pine-bluestem ecosystems in the Ouachita Mountains of the southern United States. These restoration efforts entail the reduction of stand density by harvesting and midstory competition control as well as the reintroduction of repeated fires. Application of these restoration practices has been shown to successfully develop communities and habitats that were abundant at the time of European settlement of this region. Currently, the U.S. Forest Service is in the process of restoring 62,730 ha of the Ouachita National Forest to a shortleaf pine-bluestem ecosystem. Although there is considerable information concerning the effects of restoration on animal and plant communities, little is known about the impacts of restoration on soils or to what degree important habitat components such as downed wood debris (DWD) changes during restoration activities. We found that initial harvesting and competition control treatments added significant amounts and changed the species composition of DWD within areas being restored. Almost 30% of the woody debris was lost and significant amounts of nutrients were displaced from DWD during initial restoration fires. However, following approximately 20 years of restoration activities, soil nutrient availability in restored stands appears to be greater or similar to that in unrestored stands. We found no evidence indicating that shortleaf pine-bluestem ecosystem restoration reduces inherent soil or forest productivity.