The effects of competing herbaceous vegetation on the growth of ponderosa pine seedlings with and without the herbicide Pronone were characterized in this 1987-1990 study. Study areas were established in 36 plantations across western Montana on Champion International Corporation's timberland (currently owned by Plum Creek Timber Company). The study sites were divided into three precipitation classes: low, medium, and high. Mean percent stem volume growth was calculated for 3 yr by precipitation class. Split-plot analyses of variance for precipitation class, treatment, and interaction were conducted across sites between treated and untreated seedlings to test for significant (a = 0.05) differences in growth. A two-dimensional plot of precipitation class by treated versus untreated trees was constructed to show growth rate trends. After 3 growing seasons, the treated seedlings showed significantly higher stem volume growth than their untreated counterparts regardless of precipitation class. The difference between treated and untreated seedlings was statistically significant. West. J. Appl. For. 14(1):48-52.
Document Type: Journal Article
Pacific Southwest Research Station, USDA Forest Service, Redding, CA 96001, (530) 242-2462;, Fax: (530) 242-2460
Publication date: January 1, 1999
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Each regional journal of applied forestry focuses on research, practice, and techniques targeted to foresters and allied professionals in specific regions of the United States and Canada. The Western Journal of Applied Forestry covers the western United States, including Alaska, and western Canada; WJAF will also consider manuscripts reporting research in northern Mexico that has potential application in the southwestern United States.