Area Size of Flora Identification for Species Diversity Assessment

Abstract

The problem of the area of flora identification in a particular territory is one of the most difficult and little discussed. Flora as a list of species of higher vascular plants is inextricably linked with two most important parameters: the size of the territory (in sq. km) and the number of species. The number of species must be sufficient to represent the main features of the flora for the climatic zone and local characteristics. For this, it is necessary to survey areas of different nature conservation status and anthropogenic transformation. We studied ten floras of the Samara-Ulyanovsk Trans-Volga region. The species discovery curve shows that with an increase in area from 100 km2, the number of species continues to grow and the end of a significant increase corresponds to an area of 400 km2, which is optimal. This area can be considered as minimum range of species composition of flora. The species composition of vascular plants of the considered territories reflects the main characteristic features of the flora: the number of species of vascular plants (610-812 species); the leading families are Asteraceae, Poaceae, Fabaceae, Rosaceae, Brassicaceae and genera: Carex, Galium, Salix, Artemisia, Potentilla. We have come to a conclusion that on the territory of the forest-steppe zone of the Middle Volga it’s necessary to use test plots of at least 400 km2 when studying the geographical distribution of floras or carrying out their comparative analysis.