CHARACTERISTICS OF FLORA IN SAMARA ZAVOLZHIE NEPOTISTIC SPECTRUM

It is known that the flora reacts on changing of composition climatic factors. Changing the composition of the head of the nepotistic spectrum, which is determined by the type of flora (first triada). Samara Region is located in Fab-zone, which in the territory of the Volga basin covers Saratov, Samara, Ulyanovsk region and the Republic of Tatarstan. In the north-western part of the Volga basin it gradually becomes Ros-zone. Changes in the composition of flora has discrete-continuous in nature. Flora in different parts of Fab-zone has its own characteristics, which is reflected in the taxonomic parameters. Most of the Samara Region is located in Zavolzhie, which forms the border of natural zones: forest-steppe and steppe. The natural conditions of these territories have their differences, and, therefore, differ in the parameters flora. The article reveals differences in the taxonomic structure of the flora of the steppe and forest-steppe part of the Samara region. These differences manifest themselves in different share of participation Fabaceae and Rosaceae. In the steppes of Samara Zavolzhja weakened the role of the family Rosaceae and enhanced Chenopodiaceae. Taxonomic analysis shows that the composition of the leading families first triad of the spectrum depends on the number of species in the description. The more species, the greater the likelihood that established triad leading families, corresponding to the zone. If the number of species in the description 500, then the leading triads stabilized.