Bird population in birch forests of the Southern Urals affected by industrial pollution: Report 2. Relationship with habitat variables

Abstract

The changes in habitat variables are analyzed according to the data of 2009 at ten sites along the gradient of pollution by emissions from the Karabash Copper Smelter (Chelyabinsk oblast): the pollution level, basic structural characteristics of phytocenosis, and abundance of leaf-eating invertebrates and epigeic invertebrates. The height of the top canopy, stand basal area, foliage cover of all forest layers, and biomass of epigeic invertebrates decrease as pollution grows. Foliar damage in birch (the indirect index of the abundance of phyllophages) changes only insignificantly. It seems impossible to differentiate the contribution of abiotic and biotic variables to the formation of the bird population in the study region because of close correlation between them. Pollution seems to affect the bird population indirectly through the changes in habitats.