American Chestnut, Rhododendron, and the Future Of Appalachian Cove Forests
Abstract - By the mid 1930s, the southern Appalachians had been heavily cutover and the dominant hardwood, American chestnut (Castanea dentata), had succumbed to the chestnut blight (Cryphonectria parasitica). Forests that had been burned on a frequent basis for millennia were now protected and fire was excluded in large degree. We estimated the pre-blight importance of chestnut in cove forests and the recovery of the overstory canopy on these rich sites following the blight and logging early in the last century. The overstory has largely recovered from the blight, although chestnut is not longer a functional component of the cove forest ecosystem. Following the blight, the successional pathway on two unlogged, old-growth sites proceeded to an oak association; on two logged sites, succession proceeded to mesophytic forests. A gradual change in the understory has occurred in many coves that threatens their future diversity and productivity. Encroaching rhododendron (Rhododendron maximum) thickets are severely inhibiting hardwood regeneration and reducing herbaceous/shrub species richness. Neither shade-tolerant nor shade-intolerant hardwood species are becoming established in canopy-gaps where rhododendron is present in moderate to high densities. Rhododendron has become an ecologically dominant species because it thrives on disturbance and, once established, inhibits other species. New management techniques will have to be developed if diversity and productivity of cove hardwood forests are to be sustained.