Spruce Budworm Damage Symptoms Related to Radial Growth of Grand Fir, Douglas-Fir, and Engelmann Spruce
Abstract:External damage symptoms in Abies grandis Dougl. (Lindl.), Pseudotsuga menziesii (Mirb.) Franco and Picea engelmannii Parry subjected to defoliation by the spruce budworm are described by four damage classes based upon the amount of dead branches and twigs, and the extent of top killing seen in the crowns. Radial growth before and during a 1944-1956 infestation was determined by analysis of sample disks. Graphical, covariance, and multiple-range tests showed that damage symptoms were related to reductions in radial increment. Reduction in radial increment generally differed significantly between damage classes. Radial increment varied along the tree boles; the greatest reductions occurred at midcrown and the least near the ground. Top killing occurred often among moderately damaged trees, particularly in grand fir. The study suggests that crown vigor symptoms, can be grouped into several classes suitable for use in damage surveys.
Document Type: Journal Article
Affiliations: Research Entomologist, Pacific Southwest Forest and Range Expt. Sta., Forest Service, U.S. Dept. Agric., Berkeley, Calif., was Research Forester, Pacific Northwest Forest and Range Expt. Sta., Portland, Oreg.
Publication date: 1967-09-01
- Forest Science is a peer-reviewed journal publishing fundamental and applied research that explores all aspects of natural and social sciences as they apply to the function and management of the forested ecosystems of the world. Topics include silviculture, forest management, biometrics, economics, entomology & pathology, fire & fuels management, forest ecology, genetics & tree improvement, geospatial technologies, harvesting & utilization, landscape ecology, operations research, forest policy, physiology, recreation, social sciences, soils & hydrology, and wildlife management.
Forest Science is published bimonthly in February, April, June, August, October, and December.
2015 Impact Factor: 1.702
Ranking: 16 of 66 in forestry
Also published by SAF:
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