Spruce Beetles Attack Slowly Growing Spruce
Twenty-five variable sample plots in Sept. 1982 and a further 17 plots in April 1983 were examined in mature stands of Picea glauca on the Kenai Peninsula, infected with Dendroctonus rufipennis since 1977-78. Recent radial growth of unattacked trees was greater than that of trees killed or unsuccessfully attacked by beetles. Radial growth of trees killed in 1982 or before 1982 did not differ, but radial growth of spruce unsuccessfully attacked in 1982 was significantly greater than that in spruce killed before 1982. Larger av. diam. and faster radial growth occurred in less dense stands. It is suggested that stand resistance to D. rufipennis could be increased by thinning to reduce tree competition and increase the vigor of residuals.
Hard, J. (1985). Spruce beetles attack slowly growing spruce. Forest Science, 31(4): 839-850.