Spatial-typological heterogeneity and environmental organization of the summer population of birds in the Middle Region of Northern Eurasia

Abstract

The area under study covered the West Siberian Plain from the Urals to the Yenisei River and the same band to the southern borders of the former Soviet Union in 1991, including a part of the Altai-Sayan mountain country, Kazakhstan, Uzbekistan, Turkmenistan, and the whole of Kyrgyzstan and Tajikistan. The results of ornithogeographic surveys carried out on routes with a length of 63000 km in 3140 habitats from May 16 to July 31 in the period from 1936 to 2013 were analyzed for this territory. More than 110 specialists took part in the study. The collected data were averaged according to the contours of natural-geographical maps. The subsequent cluster analysis revealed the presence of three systems (series) of bird communities in undeveloped and developed lands, as well as in water and riparian areas. Eight types of communities were distinguished within the first system: 1—tundra type; 2—forest-tundra type; 3—forest type; 4 and 5—West Siberian meadow-steppe and semidesert-steppe types; 6 and 7—Middle Asian northern desert-steppe and southern desert types; 8—high-mountain type. The borders of their distribution do not coincide with the zonal borders. Seven and six types of communities were distinguished in the second and third systems, respectively. A part of them was divided into 29 subtypes in total. The revealed heterogeneity of bird communities is largely determined by 12 environmental factors. The greatest correlation was detected for forestation, buildup, and watering. The multiple correlation of the bird population variability with all the identified environmental factors amounted to about 54 ± 1% of variance in the similarity matrix, which approximately corresponds to the correlation coefficient of 0.74.