Portland State University. Department of Biology
Date of Award
Master of Science (M.S.) in Biology
1 online resource (34 leaves, mounted ill. 28 cm.)
Salmonberry, Douglas fir
One serious problem faced by the forest industry in the Pacific Northwest is poor regeneration of commercial trees on land which is harvested and subsequently dominated by brush species. In Coastal Oregon, salmonberry is one of these brush species. Detailed investigations of field sites indicate that light intensity in the brush stands was low but sufficient for germination and early growth of Douglas-fir seedlings and soil moisture percentages and nutrient levels were high enough to support early Douglas-fir growth. Laboratory tests demonstrated the presence of leachable phytotoxins in the leaves of salmonberry. The hypothesis resulting from this study is that salmonberry releases a phytotoxin that in synergism with environmental stresses (i.e., light), suppresses germination and growth of Douglas-fir seedlings in the field.
Still, Kenneth Ray, "Mutual exclusion between Salmonberry and Douglas-fir in the Coast Range of Oregon" (1972). Dissertations and Theses. Paper 963.