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A comparison of some classification methods used to determine benthic macro‐invertebrate species associations in river survey work based on data obtained from the River Ely, South Wales
Author(s) -
LEARNER M. A.,
DENSEM J. W.,
ILES T. C.
Publication year - 1983
Publication title -
freshwater biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.297
H-Index - 156
eISSN - 1365-2427
pISSN - 0046-5070
DOI - 10.1111/j.1365-2427.1983.tb00654.x
Subject(s) - invertebrate , linkage (software) , relative species abundance , ecology , abundance (ecology) , macro , multidimensional scaling , statistics , benthic zone , correlation coefficient , mathematics , environmental science , biology , computer science , biochemistry , gene , programming language
SUMMARY. The results of a survey of the macro‐invertebrates of the polluted River Ely, South Wales, are used as a basis for comparing several classification methods which have been used previously in river survey work to determine species groupings. The methods compared are product‐moment correlation (clustered by the nearest neighbour technique), Kendall's tau coefficient (clustered by the nearest neighbour and average linkage techniques), and Squared Euclidean‐Distance coefficient (clustered by nearest neighbour and Ward's techniques). The species groupings determined by these methods were influenced both by the association coefficient and the technique used to cluster it. Some species were grouped together by all or most of the methods. The ecological validity of these robust groups is examined. A clear recommendation regarding the most appropriate method is frustrated by incomplete knowledge of the ecological requirements of most of the aquatic macro‐invertebrates used in the data‐set. However, Kendall's tau coefficient clustered by the average linkage technique appeared to produce ecologically meaningful species groups. Product‐moment correlation was also reasonably successful and since it is based on absolute abundance data whereas Kendall's tau coefficient is based on relative abundance data, the use of the two together is recommended for determining robust groups.