Characteristics of Ulmus pumila L. coenoflora in Western Transbaikalia

The peculiarities of the Ulmus pumila L. coenoflora of the natural communities in the Western Transbaikalia are discussed in the article. This species is located at the northwestern border of the area. The systematic, ecological, biomorphological composition of the U. pumila community coenoflora is considered in comparison with the U. pumila formations from Eastern Transbaikalia and the similar in genesis formation of the Armeniaca sibirica of the Selenga middle mountains. The spectrums of the predominant families and genus in the formations shows their high similarity. Analysis of the ecological composition of U. pumila community coenoflora in Western Transbaikalia confirms its steppe character. In the geographical structure, the Southern Siberian and Eurasian elements of the flora are prevailed. The influence of the East Asian and Dauro-Manchurian centers of flora formation is considerably weakened, whereas the South Siberian center becomes decisive. The method of calculation of species activity was used, which showed the most important phytocoenotic role of Spiraea aquilegifolia and herbaceous species - edificators and diagnostic species of Central Asian and South Siberian true and meadow steppes.