Levels-of-growing-stock cooperative study in Douglas-fir: report no. 08—The LOGS Study, 20-year results.

Abstract

This progress report reviews the history and status of the cooperative levels-of-growing-stock study in coast Douglas-fir, begun in 1961, in Oregon, Washington, and British Columbia. It presents new analyses, including comparisons among some installations. Data now available are primarily from the site II installations, which are approaching completion of the study. Growth is strongly related to growing stock. Thinning treatments have produced marked differences in volume distribution by tree sizes. During the fourth treatment period, current annual increment was still about double the mean annual increment, and differences in volumes and size distributions among treatments have been increasing rapidly. There are considerable differences in productivity among installations, beyond those accounted for by site index differences. The LOGS study design is evaluated.

Citation

Curtis, Robert O.; Marshall, David D. 1986. Levels-of-growing-stock cooperative study in Douglas-fir: report no. 08—The LOGS Study, 20-year results. Res. Pap. PNW-RP-356. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Forest and Range Experiment Station. 124 p