Partialling out the Spatial Component of Ecological Variation

TLDR

The authors propose a method to partition species abundance variation into pure spatial, pure environmental, spatial component of environmental influence, and undetermined components. Using canonical ordination techniques and existing computer programs, the method partials out the intrinsic spatial component from species–environment relationships and is illustrated with oribatid mites, forest vegetation, and aquatic heterotrophic bacteria. In the aquatic heterotrophic bacteria case, the method proved complementary to partial Mantel tests.

Abstract

A method is proposed to partition the variation of species abundance data into independent components: pure spatial, pure environmental, spatial component of environmental influence, and undetermined. The new method uses pre—existing techniques and computer programs of canonical ordination. The intrinsic spatial component of community structure is partialled out of the species—environment relationship in order to see if the environmental control model still holds. The method is illustrated using oribatid mites in a peat blanket, forest vegetation data, and aquatic heterotrophic bacteria. In this latter example, the new method is shown to be complementary to another approach based on partial Mantel tests.