Preliminary study of the ordination and classification of macroinvertebrate communities from running waters in Victoria, Australia

Abstract

Data on undisturbed lotic macroinvertebrate communities were assembled from a number of studies carried out in Victoria over the past 15 years; species-level information for 40 sites on nine rivers was available. Ordination (DECORANA and semi-strong hybrid multidimensional scaling) and classification (flexible UPGMA and TWINSPAN) techniques were used to assess the similarity of community composition among the sites. Correlation of environmental variables with both ordinations indicated that factors related to altitude and substratum were the most obvious gradients; a conductivity gradient was also present. The classification analyses identified four groups of sites that matched the altitudinal trends evident in the ordinations; but these techniques did not emphasize the substratum gradient. TWINSPAN also identified six groups of taxa that were characteristic of particular altitudes or regions or were widespread across all sites. The distinctiveness of the patterns from this preliminary study indicates that it would be worthwhile extending these analyses to much larger data sets from Victorian rivers.