This study determined if sheep grazing could control competing vegetation in Douglas-fir (Pseudotsuga menziesii) plantations in Pacific Northwest coniferous forests. Two years of sheep grazing reduced growth of understory brush and forbs compared to non-grazed areas. In general, utilization of brush by sheep was moderate to heavy, except in the spring of 1982, when brush was lightly utilized. Sheep grazing effectively reduced both total understory plant growth and brush net current year's growth on all plantations. Grazing increased the diameter of Douglas-fir trees at the end of the grazing season in both years. Trees in grazed plantations had greater heights and diameters three growing seasons after grazing was applied, suggesting that grazing can have long-term effects on tree growth. Based on these results, the authors concluded that sheep grazing may be effectively used as a silvicultural tool in brush control in coastal Douglas-fir forests.
Citations and enhanced abstracts for journals articles and documents focused on rangeland ecology and management. RSIS is a collaboration between Montana State University, University of Idaho, and University of Wyoming.