Annual rings of Douglas-fir, Pseudotsuga menziesii (Mirb.) Franco, which sustained 1 year of defoliation by the western false hemlock looper, Nepytia freemanii Munroe (Lepidoptera: Geometridae), showed a period of decrease in breast height ring width starting in the year that followed the damage. The magnitude of the decrease was related to the degree of defoliation: there was no ring width decrease on trees that were 0-10% defoliated; the decrease became progressively more noticeable in trees which sustained increasingly higher defoliation; and it was maximum in trees which sustained 91-100% defoliation. This period of reduction lasted 1 to 5 years and was followed by a period of above-normal growth which was related to defoliation in a similar manner: it was absent in trees 0-10% defoliated and maximum in the 91-100% tree defoliation class. Increase in defoliation caused a significant increase in index standard deviation, autocorrelation and mean sensitivity.
| Identifer | oai:union.ndltd.org:arizona.edu/oai:arizona.openrepository.com:10150/261809 |
| Date | January 1988 |
| Creators | Alfaro, R. I., MacDonald, R. N. |
| Contributors | Forestry Canada, Pacific Forestry Centre, Victoria, British Columbia, Department of Computer Science, University of Victoria, Victoria, British Columbia |
| Publisher | Tree-Ring Society |
| Source Sets | University of Arizona |
| Language | en_US |
| Detected Language | English |
| Type | Article |
| Rights | Copyright © Tree-Ring Society. All rights reserved. |
| Relation | http://www.treeringsociety.org |
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