Habitat area or habitat structure?

Posted on May 26, 2009

A basic tenet of ecological theory is that numbers of species tend to increase with the area of available habitat.  However, numbers of macroinvertebrate species and individuals living in a lake-fed river inFinlandwere unrelated to the area of the stones on which they occur.  Habitat complexity seemed to be more important than habitat area because species richness and numbers of individuals were closely correlated with the cover of bryophytes (mosses and liverworts), which provide significant opportunities for refuge and feeding.

Reference:  Heino, J. & Korsu, K.  2008.  Testing species–stone area and species–bryophyte cover relationships in riverine macroinvertebrates at small scales.  Freshwater Biology 53, 558–568.