Environmental analysis of Upper Alpine rock-and-talus flora of central and eastern parts of the Russia’s Caucasus Region

The paper presents the results of a detailed environmental analysis of the Upper Alpine rock-and-talus flora of the central and eastern parts of the Russia’s Caucasus Region. The classification of petrophytes (obligate, facultative and contingent) with respect to the acidity of the substrate (oxylophiles, xylo-calciphiles, calciphiles) and with regard to the substrate type (rupestrophytes, lapidophytes, schistophytes, lapishistophytes, morenophytes, glareophytes) is given. The species, quantity and percentage of each environmental group are indicated. The dominance in the studied flora with respect to acidity of the substrate of oxylophytes is noted, along with the physical state – lapishistophytes. In terms of the physical properties of the substrate, the flora species represent quite complex aggregate formed by stenotopic and environmentally plastic species settling on two to three, less often on four types of the substrate.