Phytocoenotic series in vegetation cover of Wrangel island 3. modeling of coenotic changes under climatic fluctuations

摘要

A conceptual model of coenotic changes in phytocoenotic series is proposed. The reason for these changes is the egression of sinusium or combination of sinusia. We can predict the main processes (irrespective of departure point in vegetation of different coenotic series) occurring in vegetation cover during climatic periods when the average rate of snow accumulation tends to increase: the expansion of territories which are occupied by willow-moss combinations of sinusia, the disintegration of stratification in principal (or relative-climax) community, the substitution of different elements in combination of sinusia, the lack of coincidence of vegetational and ecotope (landscape) boundaries, the increase of horisontal structurens at one of the hierarchic levels of vegetation cover (micro). The universal feature of vegetation cover in Wrangel island is a potential capacity of willow-moss combination of sinusia for the occupation of most habitats during the climatic period of increasing the snow accumulation.