Variety of forms of phytoliths of Kulunda soils and their phytocenotic affiliation

Abstract

Phytoliths are an important component of soil and vegetation cover. Thanks to phytolith analysis, it is possible to identify vegetation cover after a long time. There is practically no information about the transition of amorphous silica in the form of phytoliths from plant mass to soil. This very important stage in the formation of the soil phytolith spectrum was considered in the works of N. K. Kiseleva. When studying the phytolith spectra of dominant grasses and sedges, she calculated the coefficient of their participation for the Mongolian steppes, and further she proposed the concept of “phytolith spectrum" In this work, we made an attempt to assess the correlation of the set of phytolith forms and their ratio in the upper soil layer with the modern composition of vegetation. For this purpose, the phytolith spectra of soils and vegetation of three ecosystems were analyzed, and the phytolith spectra of modern soils were compared. We also applied the approach of Nina Kiseleva and the results we obtained of taxonomic diagnosis of plant species based on the forms of their phytoliths. The research was carried out on the territory of the North Kulunda lacustrine-alluvial plain. The phytolith complex of the surface layer of soils of the forb-fescue with wormwood steppe is characterized by the predominance of two groups of phytoliths: truncated cone-shaped (RONDEL) phytoliths and trapezoidal wavy plates (CRENATE). In the soils of the bushy feather-grass-forb steppe and solonetzic steppe with a cereal-licorice community, trapezoidal polylobed plates (CRENATE) and bilobed particles (BILOBATE) are added to them. Other indicator forms are presented in small quantities. Calculation of the soil phytolith complex allows one to diagnose the coenotic composition of cereals of the phytolith spectrum.