Silvicultural knowledge and practice have been evolving in the Pacific Northwest for nearly a century. Most research and management activities to date have focused on two major topics: (1) methods to regenerate older, naturally established forests after fire or timber harvest; and (2) growth and management of young stands. Today forest managers can reliably regenerate the major conifer and hardwood species under most conditions by using combinations of natural and artificial regeneration. They also can control stand density and species composition and growth of individual trees, thereby influencing stand structure. Available growth models can reasonably predict the outcome of growing conifer stands under a range of densities, species composition, and management scenarios, providing tree numbers by size class as well as crown characteristics and wood yields.Most silvicultural efforts have been financed through and directed toward production of wood. Although some other values have been produced or improved in conjunction with such activities, public interest and emphasis on nontimber values have increased. It has become apparent that some values are not benefitted by silvicultural practices aimed solely at wood production. In most situations, however, desired nontimber values can be enhanced by silvicultural measures implemented for their direct benefit or by some modifications of practices applied primarily to produce wood. We discuss the historical development of silviculture in the Pacific Northwest and review the silvicultural practices currently available to forest managers. We then point out how these practices can be modified and used to maintain and produce wildlife habitat, diverse stand structures (including those usually associated with old forests) and pleasing scenery, while also producing wood products. Most of the silvicultural knowledge needed to design and implement regimes for integrated production of these multiple values already exists.Keywords: Ecosystem management, multiple use, silvicultural systems, wildlife habitat, thinning, landscape management, forest ecology, Douglas-fir.
Contents
Regeneration Methods
Natural RegenerationDirect Seeding and Planting
Shaping Development of Young Natural Stands and Plantations
Social Expectations and Silvicultural OpportunitiesEarly Density Control The above quotation, from the preface to the first edition of Foundations of Silviculture Upon an Ecological Basis (Tourney 1928), emphasizes the fact that silvicultural practice and the research in silviculture and the ecological relations that underpin it antedate the settlement of much of North America. The early foresters in the Pacific Northwest (and elsewhere in the United States) began with forest management concepts imported from Europe. These concepts were in part unsuited to the economic and social conditions existing in the United States at that time (ca. 1900), and to species and climatic conditions that differed somewhat from those of Europe. But this introduction of forestry concepts began a con...
The effects of herbaceous weed competition on loblolly pine (Pinus taeda L.) development during the first year of plantation growth were investigated on five sites across the South. Seedling height-growth response to weed control in relation to soil type, soil moisture, soil nutrients, and weed-infestation levels was examined. Seedling height response to weed control was significantly related to percent ground cover of weeds 7 weeks after herbicide applications and to weed biomass accumulation at the end of the growing season. Plant moisture measurements and analysis of precipitation occurrence indicated that weeds depleted the soil moisture necessary for maximum pine height development. Twelve-and four-fold increases in pine biomass due to weed control occurred on sites in Arkansas and Oklahoma, respectively. Results demonstrate the benefits of total weed control to loblolly pine seedlings during the first three years on two sites.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.