Variation In Phenology And Monoterpene Patterns Of Defoliated And Nondefoliated Douglas Fir Pseudotsuga Menziesii Var Glauca

Author : Rose-Marie Muzika
Publisher : Forgotten Books
ISBN 13 : 9780428978389
Total Pages : 22 pages
Book Rating : 4.9/5 (783 download)

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Download or read book Variation in Phenology and Monoterpene Patterns of Defoliated and Nondefoliated Douglas-Fir (Pseudotsuga Menziesii Var. Glauca) (Classic Reprint) written by Rose-Marie Muzika and published by Forgotten Books. This book was released on 2018-01-13 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt: Excerpt from Variation in Phenology and Monoterpene Patterns of Defoliated and Nondefoliated Douglas-Fir (Pseudotsuga Menziesii Var. Glauca) Although resistance traits are controlled genetically, their phenotypic expression can be modified substantially by environmental factors (hanover 1975, Mattson and Haack Although environmentally induced phenotypic variation would be minimal for individuals of the same species occupying a relatively comparable microsite, they exhibit differential levels of defoliation (mcdonald 1979, 1981; Perry and Pitman 1983) Because foliage quality, particularly secondary chemicals, seem to play a significant role in plant-host susceptibility and resistance, the hereditability of chemicals such as mono terpenes (squillace 1976) may be beneficial for tree breeding. An important question is whether observed differences in defoliation by Douglas-fir provide a potential manage ment opportunity, that is, whether they would be useful in tree improvement. One of our objectives was to determine if differences in the monoterpene composition of new foli age contribute to differences observed between severely and slightly defoliated Douglas-fir trees. We tested this by examining pairs consisting of each type of tree in an area that is currently undergoing a severe budworm outbreak. A second objective was to determine differences in foliage phenology between trees resistant and those susceptible to budworm to assess if this attribute makes some trees resistant to spruce budworm. The study area was about 8 kilometers east of Cove, Oregon, in the wallowa-whitman National Forest at 1640 meters elevation. Ten pairs of Douglas-fir trees were selected in a mixed-conifer stand experiencing heavy defoliation by C. Occidental/s. Estimates of insect densities for 6 years before the study indicated outbreak populations of 91 to 417 instar lv larvae per square meter of branch area.' We chose pairs of trees that had simi lar diameters and microsites and showed large differences in levels of C. Occidentalis defoliation (table Each tree was within 3 meters of its counterpart. Slopes at the site ranged from 15 to 40 percent and were the same for each tree pair. One tree of each pair exhibited minimal previous-year defoliation, and the other tree exhibited medium to heavy defoliation. The extent of defoliation from previous years was estimated visually. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.