Growth of White fir after Douglas-fir tussock moth outbreaks: long-term records in the Sierra Nevada.

Abstract

Radial growth of white fir trees, Abies concolor (Gord. and Glend.) Lindl. ex Hildebr., defoliated almost 30 years ago by Douglas-fir tussock moth, Orgyia pseudotsugata (McDunnough), in the central Sierra Nevada was compared with 22 years of growth prior to the outbreak. There was little difference in growth between the two periods indicating that enhanced growth of defoliated trees after the out-break did not occur as reported for two other California outbreaks. Increment cores also revealed for the first time an even older outbreak, which occurred on the same site in 1906-8.

Citation

Wickman, Boyd E. 1986. Growth of White fir after Douglas-fir tussock moth outbreaks: long-term records in the Sierra Nevada. Res. Note. PNW-RN-440. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 8 p