© 1989 by Institute of Chartered Foresters
Stand Growth Efficiency in a Douglas Fir Thinning Trial
College of Forest Resources AR-10, University of Washington, Seattle, Washington 98195, USA
Stand growth efficiency, or the ratio of periodic stand volume growth to sapwood basal area, was measured in a long term Douglas fir (Pseudotsuga menzieSü (Mirb.) Franco) thinning trial in coastal Washington, USA. Sapwood basal areaas a surrogate for leaf areaand volume growth were estimated in two fifth-hectare plots from each of three thinning treatments, and from a single fifth-hectare control plot. Stand growth increased with increasing sapwood basal area. No distinct pattern of stand growth efficiency with sapwood basal area was evident. Large differences in efficiency between plots of the same treatment were found and were attributed to differences in stand structure, or the arrangement of tree sizes.