Formation of phytocoenotypes in soils of different degree of erosion

The paper focuses on issues related to problems of eroded soils and subsequent processes of development of serial communities aimed at formation of a stable climax phytocoenosis. A series is considered as a set of species that briefly inhabit a given territory replacing each other. Soil erosion development is caused by anthropogenic and natural factors; hence, this process is of a mixed natural-anthropogenic type. Soil erosion on slopes with elemental landscapes of any exposure affects the environmental conditions for the formation of phytocoenotypes and species composition of plant communities due to secondary successions and variation in dominants and subdominants. In this case, plant communities of herbaceous phytocoenoses of eroded soils exhibit both sequential and rapid changes in species composition with the appearance of species adapted to decreased soil fertility. The orientation, rate and number of successional changes depend on the intensity of erosion development. Severely eroded soils significantly increase the heterogeneity of the soil environment, creating optimal conditions for introduction of species that are often nontypical of the considered phytocoenoses; the number of assectators therefore increases in soils of this type. In case weakly eroded soils are used as the control, the number of assectators in severely eroded soils increases two to three fold, with possible fluctuation changes aimed at reducing assectators due to ecotopic and phytocoenobiotic selections.