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Diameter prediction models based on the Weibull distribution function and stand-table projection models based on changes in relative diameter were developed for 2- to 10-year-old Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) plantations. Both modeling approaches incorporated the effects of site preparation, animal protection, and competing vegetation. The diameter distribution approach is appropriate when information on initial diameters is not available. The stand-table projection approach may be applied when tree diameters in a plantation are measured two or more growing seasons after planting. At young ages, the stand-table approach provided more accurate representation of observed diameter distributions than the diameter distribution approach. At age 10 the two methods provided comparable diameter distributions. The equations derived for predicting survival, height growth of dominant trees, height–diameter relationships, and the development of woody vegetation over time will facilitate the study and comparison of stand structure and dynamics after various site-preparation and animal-protection treatments.

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This publication reports research involving pesticides. It does not contain recommendations for specific uses, nor does it imply that the uses reported on currently are registered. All uses of pesticides must be registered by appropriate State and Federal agencies before they can be recommended. CAUTION: Pesticides can be injurious to humans, domestic animals, desirable plants, and fish or other wildlife-if they are not handled or applied properly. Use all pesticides selectively and carefully. Follow recommended practices for the disposal of surplus pesticides and pesticide containers. Pesticide Statement WILLIAM I. STEIN is a principal plant ecologist (emeritus), Forestry Sciences Laboratory, 3200 SW Jefferson Way, Corvallis, OR 97331. Author Stein, William I. 1999. Six-year growth of Douglas-fir saplings after manual or herbicide release from coastal shrub competition. Res. Pap. PNW-RP-500. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 55 p.Survival and growth of planted Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) saplings and associated shrubs were observed after seven release treatments had been installed side by side in a large-scale experiment replicated on four areas in the Coast Ranges of Oregon. After 6 years, total height, stem diameter, and crown radius of Douglas-fir were greater in treated areas than in untreated areas. Four times as much Douglas-fir volume as in the control was produced by one manual cutting of competing brush, which also represented the best economic return. Trees subjected to a second and third manual treatment did not grow as much as those with one manual treatment nor did those released with glyphosate or fosamine herbicide or a combination manual plus fosamine treatment. Survival averaged 95.9 percent during the 6-year period.Six years after treatment, shrub cover was significantly greater around trees in untreated than in treated areas but did not differ significantly in average height. Dominant competitors in untreated areas averaged nearly two-thirds of tree height, those in treated areas only one-third. Effects of herbicide treatment were most visible on red alder (Alnus rubra Bong.), salmonberry (Rubus spectabilis Pursh), and red elder (Sambucus callicarpa Greene). Diversity of competing species temporarily increased after release treatments.In the highly productive forests of the Pacific Coast Ranges, competition from fastgrowing shrubs can reduce the survival and slow the growth of planted Douglas-fir (Pseudotsuga menziesii (Mirb) Franco). 1 Overtopping by competitors and concurrent setbacks from animal damage can be major impediments to development of fastgrowing, well-stocked stands. Though release effects of some herbicides were well known when the study was started, results achievable with newer selective herbicides and by manual methods were fragmentary, and these release methods had not been compared directly. This cooperative endeavor, initiated in 1980-81 between the Siuslaw National Forest and the Pacifi...

In principle, the oil milling process is straightforward. The wide variety of equipment in use reflects, however, a multiparametric process. The main limiting parameters are kind of seed, oil content, particle strength, particle structure, temperature, moisture, particle size, residence time, mechanical forces, etc. Additionally, the seed specific parameters vary not only between kinds of seed but also for the same seed, due to different conditions in climate, soil, and harvesting. Therefore, equipment design must be widely based on statistical averages of the limiting parameters. In other words, exact precalculation of the single technological steps is impossible. As a consequence, for more than 5,000 years, the oil milling process has been in the stage of being optimized. The acutal technical standard is very satisfying, but there is still a strong need for further research and development. Currently, as in the past, the oil milling process seems to be not so much a science as an art.