Epicormic branching of California black oak: effect of stand and tree characteristics

Abstract

Young California black oak (Quercus kelloggii Newb.) stands usually require thinning to increase production of acorns and wood products, but epicormic branches, which yield no acorns and constitute a serious lumber degrade. often result. A crown thinning in 60-year-old hardwood stands on a south exposure at the Challenge Experimental Forest in thenorthern Sierra Nevada of California created basal areas that ranged from 20 to 35 m2 per ha. Trees in a control and bordering small openings expanded the basal area range. In 1976 or 6 to 9 years after thinning, 2069 living and dead epicormic branches on 189 California black oak trees were observed. Statistically significant (alpha = 0.05) predictors of epicormic branching were position in stand, cardinal directionof bole face, and bole segment-variables that generally affected epicormic branching on eastern species of deciduous oaks. Number of epicormic branches increased with decreasing stand density, proximity to openings, on south and east bole faces. and with increasing distance above the stump. These findings, together with silvicultural recommendations for enhancing crown development and lessening epicormic branching of California black oak, are discussed.

Citation

McDonald, P.M.; Ritchie, M.W. 1994. Epicormic branching of California black oak: effect of stand and tree characteristics. Northwest Science Journal. 68(1): 6-10.