Douglas-fir levels of growing stock study (LOGS) data from the Pacific Northwest

A regional cooperative study, known as the Douglas-fir levels of growing stock study (LOGS), began in 1961 in Oregon, Washington, and British Columbia with a total of nine study areas. The program objective was to determine the relationships between volume growth, basal area growth, and diameter growth, to growing stock levels for a standard set of eight thinning regimes in Douglas-fir stands 20-40 feet tall and continued through 60 feet of height growth. This data publication contains the 1961-2006 data for the three study areas maintained by the USDA Forest Service, Pacific Northwest Research Station: Iron Creek, Rocky Brook, and Stampede Creek. Tree measurement data from all planned measurements are included plus some additional measurements beyond the planned measurement schedule. Data include, but are not limited to, tree height, diameter at breast height, height of the live crown from the ground, crown class, damage codes, and species.
The LOGS study was not a comparison of operational thinning regimes, but was designed to establish relationships between growth and growing stock. The most effective use of applying LOGS study results will probably be their use, in conjunction with other data, in construction and refinement of stand simulators or other growth relationships. The LOGS study provides a unique set of high-quality data from young stands maintained at relatively low densities; a condition which was not common when the study was established.