Abstracts

Diversity of the Fauna

The results of the summer and winter routing accounts which have been carried out in 1983 -88 are included in the analysis. In total are surveyed 31 habitats (from virgin fir-spruce woods up to large cities). Construction of graphs of similarity of communities and estimation of hierarchy of natural-anthropogenesis regimes determining territorial variability of the bird communities, are executed by factor analysis methods.

In the first half of summer spatial-typological structure of the bird communities is determined mainly by seven gradients: forest cover percent, built-on area, industrial landscape transformation, influence of an circumjacent landscape, water area percent, increase of water temperature, and also by general strengthening of anthropogenesis influence.

In the second half of summer prevailing trends of the bird communities as a whole are remaining the same. The differences consist in the following. The heterogeneity of the wood bird assemblages is caused in the greater degree by age of wood plantings, than by their species composition. The bird communities of nonwood habitats become more similar owing to bird postbreeding movements. In cities and villages the general influence of urbanization amplifies, but not building types, as in the first half of summer.

In the winter period wood and settlement variants step-type behaviour of differences from all others sharply amplify (accordingly, on gradients of forest cover percent and built-on area). In this season the significance of a circumjacent landscape for formation of bird communities of open habitats is maximum. In the whole circuit, still, is oriented according to increase of anthropogenesis influence.

The spatial organization of the bird's communities in first half of summer on 90 % is explained by 27 natural-anthropogenesis regimes; in second half - 31 (informativity - 89 %); in winter time - 26 (87 % of discounted variance). The comparison of spatial organization of the bird communities in the Urals southern taiga with the published data about adjoining regions has shown, that the revealed regional features are caused, mainly, by specificity of geomorphology and economic development. However, to speak about a natural originality is difficult enough, since in Middle Urals, as well as in Southern, the current spatial heterogeneity of bird communities in many respects is determined by anthropogenesis transformation of environment. Specificity of development of Middle Urals is that the anthropogenesis transformations initially have increased a typological variety of landscapes by this of a primary quite homogeneous geographical region. Accordingly, the variety of bird communities increased, and, probably, species richness grew at the first stages of development.

Note. Abstracts are published in author's edition

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