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Evenness Indices Measure the Signal Strength of Biweight Site Chronologies

The signal strength of a biweight site chronology is properly viewed as an outcome of analysis rather than as a property of the forest-climate system. It can be estimated by the evenness of the empirical weights that are assigned to individual trees. The approach is demonstrated for a 45-year biweight chronology obtained from 40 jack pine (Pinus banksiana Lamb.) trees. The annual evenness of the empirical weights is calculated by indices derived from the Shannon and Simpson diversity indices, and the variances are found by the jackknife procedure. The annual estimates are then averaged to find an overall estimate of biweight signal strength for the 45-year period. These techniques are most useful for determining sample sizes for the biweight procedure, and for comparing different methods of detrending and standardizing data sets prior to applying the biweight mean-value function.

Identiferoai:union.ndltd.org:arizona.edu/oai:arizona.openrepository.com:10150/261927
Date January 1990
CreatorsRiitters, Kurt H.
ContributorsManTech Environmental Technology, Inc., Research Triangle Park, North Carolina
PublisherTree-Ring Society
Source SetsUniversity of Arizona
Languageen_US
Detected LanguageEnglish
TypeArticle
RightsCopyright © Tree-Ring Society. All rights reserved.
Relationhttp://www.treeringsociety.org

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