Effects of alternative silviculture on stump sprouting in the southern Appalachians

Abstract

Stump sprouts are an important form of regeneration for a number of species in the southern Appalachians, especially the oaks ( Quercus spp.). Alternative regeneration systems to clearcutting such as shelterwood and leave-tree systems are being implemented in many hardwood stands in the Appalachians. However, the effects of these alternative silvicultural systems on stump sprouts are not known. Therefore, we evaluated the impact of three silvicultural systems: a clearcut, leave-tree, and shelterwood on stump sprouting. These treatments were implemented in seven stands in Virginia and West Virginia in the Appalachian Plateau (AP) and Ridge and Valley (RV) physiographic provinces. The stands were even-aged oak dominated Appalachian hardwood stands with ages ranging from 62 to 100 years. Species were placed into six groups: (1) red oak ( Quercus spp.), (2) chestnut oak ( Q. prinus L.), (3) white oak ( Q. alba L.) and hickory ( Carya spp.), (4) red maple ( Acer rubrum L.), (5) mixed mesic, and (6) midstory groups. Partial harvesting also reduced the number of sprouts per stump for the red oak group and red maple. Sprouting probabilities were generally less in the Appalachian Plateau than the Ridge and Valley, particularly for the oaks ( Quercus spp.). Partial harvesting systems decreased sprouting in both physiographic provinces. However, the sprouting in specific species groups varied between the two physiographic provinces. In the Ridge and Valley, the highest sprouting rates were in the clearcut for the red oak (60%), chestnut oak (77%), white oak–hickory (26%), and midstory (33%) species groups. Red maple sprouting was highest in the leave-tree (67%) in the Ridge and Valley. The mixed mesic and midstory groups were only reduced in the Ridge and Valley. Sprouting was negatively correlated with residual basal area for the red oak group, chestnut oak, and red maple. For the all oak species except white oak, sprouting was reduced by about 2% for every 1m 2/ha increase in residual basal area.