Management Of Pacific Douglas-Fir Stands To Maintain Black-Tailed Deer Populations :: Environment Animals Environmental Essays

Management Of peace-loving Douglas-Fir Stands To Maintain Black-Tailed Deer PopulationsIntroductionWithin the Pacific Northwest region of the United States, intensive, even-aged silviculture has simplified the structure and species composition of natural forest stands. Within the range of the coastal Pacific Douglas-fir (Pseudotsuga menziesii), old-growth forests presently speak only 13 percentage of the region 60 percent of these remnants number in patches less than 40 hectargons in size. In this region, total let down nation consisting of old-growth forest before extensive logging has been estimated at 60-90 percent (Williams and Marcot 1991). As a result of intense clearcutting practices, early successional stages have frame predominant and later stages have declined. Shifts in age classes of forests have been accompany by changes in composition and abundance of fauna. Declines in population numbers, changes in conception dates, and an increase to 27 percent annual mortal ity (vs 5% in higher elevation old-growth stands) are a cause for implementing tolerate silvicultural practices in Douglas-fir stands managed for both timber production and a stable black-tailed cervid (Odocoileus hemionus columbianus) population (McNay and Voller 1995, Brown 1992). This business relationship will attempt to describe a fairly new and promising silvicultural method that can potentially be able to satisfy both of these criteria. Coastal Douglas-Fir CharacteristicsThe habitat type that this report is concerned with is the Tsuga heterophylla partition which contains a large geographical area west of the crest of the Cascade Mountains. Much of the central portion of this zone is occupied by subclimax forests reign by coastal Douglas-fir (Williamson 1983, Scott 1980). The rest is dominated by western hemlock (Tsuga heterophylla). The original old-growth forest, whose origin was primarily periodic, ruinous fire, frequently had understory components of western hemlock and western redcedar (Thuja plicata). On very xerophytic soils, Douglas-fir may be the major species of the climax stand. Douglas-fir is a species of medium tolerance, retentive life, large size, and rapid juvenile height growth. It does not sprout, but after(prenominal) 25 years of age bears good seed crops every 5 to 7 years. The seed disseminates well to about six tree lengths and up to one-half mile. Unmanaged stands vary between 81 and 190 cubic feet mean-annual ontogenesis at age sixty. Scott (1980) suggests that average yields of about 300 cubic feet per acre are possible in managed stands. For maximum yield, Douglas-fir is commonly grown on rotations of 40 to 60 years, depending on the site and the landowners objectives.