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Full-Text Articles in Physical Sciences and Mathematics
Applying Height Growth And Site Index Curves For Inland Douglas-Fir, United States Department Of Agriculture, Forest Service
Applying Height Growth And Site Index Curves For Inland Douglas-Fir, United States Department Of Agriculture, Forest Service
Forestry
Methods for estimating both site index and dominant height growth for inland Douglas-fir in the Northern Rocky Mountains are presented and discussed. The methods should be applicable over a wide range of stand conditions because no restrictions were placed on species composition, stand density, spacing, or age structure in the original stem analysis sample. Increased accuracy can be obtained if habitat type is considered, because the shape of the site index curves varied with respect to three major habitat series groupings. Results are summarized in the form of equations, tables, and graphs. Precision curves are used to illustrate the relationship …
Release Of A Thinned Budworm-Infested Douglas-Fir/Ponderosa Pine Stand, United States Department Of Agriculture, Forest Service
Release Of A Thinned Budworm-Infested Douglas-Fir/Ponderosa Pine Stand, United States Department Of Agriculture, Forest Service
Forestry
Current and past defoliation by western spruce budworm (Choristoneura occidentalis Freeman) in an 80-year-old predominantly Douglas-fir (Pseudotsuga menziesii var. glauca [Beissn.] Franco) stand thinned to 14 by 14 feet was significantly lower than in a nearby untreated stand of similar age, species, and site conditions. Analysis of periodic radial growth ratios indicated that prior to thinning, Douglas-fir had been heavily defoliated by budworm and growth was seriously depressed. Following thinning, the host leave trees developed dense crowns and 10-year radial growth increased an average of 57 percent: meanwhile, radial growth of nonhost ponderosa pine (Pinus ponderosa Dougl.) increased 38 percent. …