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Comparison of species ordinations resulting from alternative indices of interspecific association and different numbers of included species

Journal Article:

Abstract

Several measures of interspecific association are compared. Dispersion and covariance are limited in value because they respond to the commonness of the species compared. Correlation is not so limited but it responds to discrepancies in commonness among the species. The practical result of these relationships between commonness and association is that only the most common species can occupy peripheral positions in a species ordination. Rare species are relegated to positions near the center not on the basis of their phytosociological pattern but simply because of their rarity. Both Cole's index of association and the tetrachoric correlation overcome the problem imposed by the relationship between ordination position and species commonness and they both produce very similar results. The effect of differing numbers of species on the ordination configuration is examined using both Pearson's correlation and Cole's index. The basic pattern of the ordination is set with the first few species when Cole's index is used, however, since rare species are given more weight in the analysis with this index, the addition of several very rare species can change the configuration of the ordination. (auth)
Authors:
Publication Date:
Dec 19, 1975
Product Type:
Journal Article
Reference Number:
ERA-01-024545; EDB-76-067237
Resource Relation:
Journal Name: Vegetatio; (Netherlands); Journal Volume: 31:1
Subject:
54 ENVIRONMENTAL SCIENCES; FORESTS; BIOLOGICAL MODELS; CORRELATIONS; DIAGRAMS; INDEXES; MATRICES; SAMPLING; TREES; VECTORS; BIOMASS; DOCUMENT TYPES; ENERGY SOURCES; PLANTS; RENEWABLE ENERGY SOURCES; TENSORS; 510302* - Environment, Terrestrial- Radioactive Materials Monitoring & Transport- Terrestrial Ecosystems & Food Chains- (-1987)
OSTI ID:
7347615
Research Organizations:
Oak Ridge National Lab., TN
Country of Origin:
Netherlands
Language:
English
Other Identifying Numbers:
Journal ID: CODEN: VGTOA
Submitting Site:
ORNL
Size:
Pages: 1-14
Announcement Date:
Sep 01, 1976

Journal Article:

Citation Formats

Goff, F G. Comparison of species ordinations resulting from alternative indices of interspecific association and different numbers of included species. Netherlands: N. p., 1975. Web.
Goff, F G. Comparison of species ordinations resulting from alternative indices of interspecific association and different numbers of included species. Netherlands.
Goff, F G. 1975. "Comparison of species ordinations resulting from alternative indices of interspecific association and different numbers of included species." Netherlands.
@misc{etde_7347615,
title = {Comparison of species ordinations resulting from alternative indices of interspecific association and different numbers of included species}
author = {Goff, F G}
abstractNote = {Several measures of interspecific association are compared. Dispersion and covariance are limited in value because they respond to the commonness of the species compared. Correlation is not so limited but it responds to discrepancies in commonness among the species. The practical result of these relationships between commonness and association is that only the most common species can occupy peripheral positions in a species ordination. Rare species are relegated to positions near the center not on the basis of their phytosociological pattern but simply because of their rarity. Both Cole's index of association and the tetrachoric correlation overcome the problem imposed by the relationship between ordination position and species commonness and they both produce very similar results. The effect of differing numbers of species on the ordination configuration is examined using both Pearson's correlation and Cole's index. The basic pattern of the ordination is set with the first few species when Cole's index is used, however, since rare species are given more weight in the analysis with this index, the addition of several very rare species can change the configuration of the ordination. (auth)}
journal = {Vegetatio; (Netherlands)}
volume = {31:1}
journal type = {AC}
place = {Netherlands}
year = {1975}
month = {Dec}
}