BROWSE AND HERBAGE YIELD FOLLOWING CLEARING IN THE ALBERTA MONTANE ASPEN ECOREGION

Abstract

Small openings were cleared by bulldozing in montane aspen Populus tremuloides forest in southwestern Alberta in 1976. Production of browse, forbs and grasses was measured at the end of the growing season 2 and 7 years later. In the 2nd year production of woody twigs was significantly higher than on uncut controls (87.0  kg/ha compared to 56.0 kg/ha). In the 7th year twig production on cut blocks still exceeded that on the control blocks (53.9 kg/ha compared to 35.5 g/ha). Leaf production was also significantly higher on the treated blocks during both years. Forb production and species composition was not significantly affected by cutting. Production of grasses increased significantly on the treated blocks in 1978 but was similar to production on the control blocks in 1983. Forage production and percentage increases following treatment were low compared to those reported from studies in aspen forests in the western United States and much lower than values reported following treatment in the boreal mixedwood forests. Decisions to use patch clearcutting to increase ungulate forage in montane aspen stands should be based on site characteristics.