Wood density-moisture profiles in old-growth Douglas-fir and western hemlock.

Abstract

Accurate estimation of the weight of each load of logs is necessary for safe and efficient aerial logging operations. The prediction of green density (lb/ft3) as a function of height is a critical element in the accurate estimation of tree bole and log weights. Two sampling methods, disk and increment core (Bergstrom xylodensimeter), were used to measure the density-moisture complex in wood. The relationship between wood density and height was best described by either quadratic or cubic polynomial functions. Prediction functions for green and dry wood density are presented for old-growth western hemlock and Douglas-fir. Sapwood and heartwood functions were analyzed separately as were trees with and without heartrot.

Citation

Pong, W.Y.; Waddell, Dale R.; Lambert Michael B. 1986. Wood density-moisture profiles in old-growth Douglas-fir and western hemlock. Res. Pap. PNW-RP-347. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 36 p