Reduction in growth of pole-sized ponderosa pine related to a pandora moth outbreak in Central Oregon.

Abstract

Defoliation by pandora moth in a ponderosa pine spacing study in 1992 and 1994 generally increased as spacings increased from 2 to 5.7 meters and then decreased as spacings increased to 8 meters. Defoliation did not increase mortality during the 1990-94 period, but volume growth was reduced. Basal area increments of sample trees were reduced 25 percent the first growing season after defoliation (1992), 30 percent the second year after defoliation (1993), and 63 percent after the second defoliation (1994

Citation

Cochran, P.H. 1998. Reduction in growth of pole-sized ponderosa pine related to a pandora moth outbreak in Central Oregon. Res. Note PNW-RN-526. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 14 p