The pollen ratio of indicator taxa in steppe and forest-steppe landscapes of Altai Krai

Abstract

The pollen ratios of key plant taxa in the spectra of palynological samples are widely used to indicate changes in vegetation, landscapes and climate. In this study, based on the analysis of pollen spectra obtained from Tauber traps and topsoil samples, the main ratios of indicator taxa (Artemisia/Chenopodiaceae (A/C) and (Artemisia + Chenopodiaceae)/Poaceae (A + C)/P) were calculated for the steppe and forest-steppe landscapes of Altai Krai. The results show that the (A+C)/P ratio calculated for pollen traps makes it potentially possible to distinguish steppe and forest-steppe landscapes. The (A+C)/P ratio has a positive correlation with the mean annual precipitation for samples collected in Tauber traps. A variety of factors significantly influence the values of the pollen ratio, including the proportion of indicator taxa in the community, their pollen productivity and volatility, as well as the structure of natural and anthropogenically transformed vegetation. In other words, the study of the zonality of the ratios of indicator taxa in pollen spectra requires a certain data set (a set of points and samples), as well as an analysis of the deviating maximum and minimum values of these ratios and the construction of a physical model of their formation taking into account all probable factors.