Author: M. J. WaterhousePublisher: British Columbia Forest Science Program
ISBN:
Category : Nature
Languages : en
Pages : 56
Book Description
"In the central interior of British Columbia (Southern Interior Forest Region), Douglas-fir (Pseudotsuga menziesii) tends to occur in even-aged stands in the Interior Cedar-Hemlock Moist, Cool, Horsefly biogeoclimatic variant (ICHmk3). Douglas-fir stands are important from both forest industry and wildlife habitat management perspectives. Mule deer require mature and older Douglas-fir stands as winter range. In these ecosystems, Douglas-fir stands are typically clearcut, thereby seriously compromising habitat value as winter range. This is a pilot study to examine the response of vegetation (percent cover) and Douglas-fir regeneration (density and growth) to a range of opening sizes, opening orientation (along and across contours), and site preparation treatment (yes or no), 5 years post-harvest. The openings (15 165 m [0.25 ha], 30 165 m [0.5 ha], 60 165 m [1.0 ha], 60 330 m and 140 140 m [2.0 ha]) are options for group selection, patch cut, or clearcut silvicultural systems. Although most of the 19 tree, shrub, and grass species that mule deer could eat did not change in percent cover from pre-harvest to 5 years postharvest, the species that did change were most strongly affected by harvesting, not opening size. A major diet component, western redcedar (Thuja plicata), was reduced from 9.6 to 1.4% in the site-prepared openings, and from 9.4 to 3.9% in the openings not site-prepared, when comparing the pre-harvest to the 5th-year post-harvest assessment. However, in the 5 years since harvesting, this species has increased from 533 stems per ha to 783 stems per ha (47%) and should increase steadily in cover over time. Of note was a big increase in red raspberry (Rubus idaeus) (from 0.1% up to 14%) and a moderate increase in birch-leaved spirea (Spirea betufolia) (from 1% up to 6%); however, they generally occur in small amounts (
