Douglas-fir seedlings were planted in 1963 near Burnt Woods, Oregon, on land covered with grass, salal, or bracken to test the effects of terracing on regeneration. After 9 years, survival was best (about 95 percent) among seedlings machine-planted along the centers of the terraces and was better on south than...
A 20-year-old Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco] stand in the Oregon Coast Range was thinned from about 1,700 to about 350 trees/ac. Subsequent thinnings, under eight different regimes, occurred at ages 23, 27, 30, and 32. Average net periodic cubic-volume growth was strongly influenced by thinning regime, varying from about...
Regression models of height growth and survival were fitted to aggregate data for trees, protected and not protected from animal damage, that had been surveyed on Douglas-fir and ponderosa pine plantations in Oregon and Washington. Animal damage significantly affected both height and survival. Dynamic programming analysis-using both soil expectation (Se)...
Tables are presented that summarize 108 published articles on forest growth and yield in the Pacific Northwest. Each table describes the form of the information presented, the species to which the information is applicable, the data sources used to develop the information, the data needed to predict growth and yield,...
Comparisons were made to determine how the uncertainty of initial inventories and projected yields affect harvest schedules for Douglas-fir. Results indicate that short-run harvests are most affected by errors in initial inventory, with the effect being less than the size of the error. Long-run harvests are most affected by yield...
Equations are presented for predicting height to crown base (or bole ratio) for fourteen species of trees common to the mixed-conifer zone of southwest Oregon. Nonlinear regression was used to fit a weighted logistic function for each species. The independent variables include height, crown competition factor in larger trees, stand...