Sampling Low Density Populations of the Douglas-fir Tussock Moth by Frequency of Occurrence in the Lower Tree Crown PDF Download

Author: Richard R. Mason
Publisher:
ISBN:
Category : Douglas-fir tussock moth
Languages : en
Pages : 16

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Author: Richard R. Mason
Publisher:
ISBN:
Category : Douglas-fir tussock moth
Languages : en
Pages : 16

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Book Description
A sequential sampling plan is described for identifying tussock moth populations which, at a maximum expected rate of increase, could be within 1 year of outbreak status. The plan uses a new technique of sampling early larvae by the nondestructive examination of lower crown foliage. Larvae at inconspicuous low densities are classified into relatively low or high categories by their frequency of occurrence on foliage samples. The sampling plan is applied independently on individual plots to classify the density of each plot. It is an appropriate method for quickly screening suboutbreak populations in ground evaluation surveys.

Author: Richard R. Mason
Publisher: Forgotten Books
ISBN: 9780364693537
Category : Mathematics
Languages : en
Pages : 26

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Excerpt from Sampling Low Density Populations of the Douglas-Fir Tussock Moth by Frequency of Occurrence in the Lower Tree Crown The first criterion of standard ization can be satisfied by a basic relationship that exists between the mean density of larvae and the pro portion of sample units that contain one or more larvae. When larvae are abundant in an area, they will appear in a greater proportion of the samples than when they are rare. The exact form of this relationship depends on the size of the sample unit and the frequency distribution of data. The relationship can be determined by regression analysis or by fitting a theoretical mathematical distribution to field data. 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.

Author:
Publisher:
ISBN:
Category : Forests and forestry
Languages : en
Pages : 544

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Author: Robert R. Mason
Publisher:
ISBN:
Category : Douglas fir tussock moth
Languages : en
Pages : 32

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Procedures for monitoring larval populations of the Douglas-fir tussock moth and the western spruce budworm are recommended based on many years experience in sampling these species in eastern Oregon and Washington. It is shown that statistically reliable estimates of larval density can be made for a population by sampling host trees in a series of permanent plots in a geographical monitoring unit. The most practical method is to estimate simultaneously densities on a plot of both insect species by the nondestructive sampling of foliage on lower crown branches of host trees. This can be done either by counting all larvae on sample branches or by estimating the frequency of occurrence of a selected threshold number of larvae in samples. Statistics are given on the expected within- and between-plot variances and the number of sample plots needed in different sized monitoring units. In large monitoring units, plot densities of tussock moth and budworm larvae usually are not normally distributed, but they can be normalized by logarithmic transformation to predict the probability of subpopulations of any given density occurring somewhere in the unit. It is urged that sampling methods be consistent and that monitoring be done annually to accumulate continuous databases that reflect the behavior of defoliator populations over a long period.

Author: Richard R. Mason
Publisher:
ISBN:
Category : Douglas fir tussock moth
Languages : en
Pages : 32

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Author:
Publisher:
ISBN:
Category : Forest insects
Languages : en
Pages : 308

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Author: Richard R. Mason
Publisher:
ISBN:
Category : Sampling (Statistics)
Languages : en
Pages : 8

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Author: Robert W. Campbell
Publisher:
ISBN:
Category : Douglas fir
Languages : en
Pages : 176

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Book Description
This annotated bibliography includes references to 338 papers. Each deals in some way with either the Douglas-fir tussock moth, Orgyia pseudotsugata (McDunnough), or a related species. Specifically, 210 publications and 82 unpublished documents make some reference, at least, to the Douglas-fir tussock moth; 55 are concerned with other species in the same genus. The subject matter in each paper has been indexed to at least one general topic (General, Taxonomy, Biology, Host Relationships, Outbreaks, Control, Related Material). Most of these general topics have been subdivided into more specific headings. For example, Host Relationships includes separate categories for white fir, grand fir, and Douglas-fir. A complete listing of the references in each general and specific category is presented in the index.

Author: Richard R. Mason
Publisher:
ISBN:
Category : Caterpillars
Languages : en
Pages : 20

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