Researchers from the Institute of Physicochemical and Biological Problems of Soil Science of the Russian Academy of Sciences have for the first time assessed the relationship between climate change, vegetation and the chemical composition of steppe soils. The results of the work were published in the journal Plant and Soil.

It is known that the ratio of chemical elements in the soil profile can be used to predict what the climate was like in previous eras. It is classically believed that the chemical composition of soils is inherited from the parent rock and in the process of soil formation, the main migration of elements occurs in the wetted zone, and in the deep layers the chemical composition remains stable. But when reconstructing the climate of the past, the question arises: how could such a chemical composition of soils have formed?

Steppe soils are characterized by very low migration activity of elements due to lack of moisture and, often, it is the above-ground vegetation that is the driving force of migration flows in the soil.
Scientists from Pushchino have studied the problem of the consequences of the change in types of terrestrial vegetation as a result of climate drying and their impact on the chemical composition of the upper soil layers of the steppe region (southern Russia).

The study showed that the drier it is (less precipitation), the more prevalent wormwood and goosefoot are in the ground cover, which actively accumulate potassium, calcium, phosphorus and sulfur in the soil. And with increased moisture, cereals grow, which increase the accumulation of all micro- and macroelements in the soil. This must be taken into account when assessing the environmental effects of further global warming, understanding that drying will lead to an increase in the content of Ca, K, P, S, Cl in plants and soil and, accordingly, to the activation of salinization.

The data obtained will contribute to a better understanding of the geochemical function of plants in modern steppes, which is necessary for predicting the response of landscapes to future climate change.

The present study covered a 1500 km climatic transect, which includes 5 zonal types of steppes and 2 types of soils. The uniqueness of the work is that the contribution of plants to the chemical composition of the upper horizons of steppe soils (20 cm, root zone), formed over about seven thousand years, was assessed. The work was supported by a grant from the Russian Foundation for Basic Research (No. 19-29-05178).

Source: Kudrevatykh, I.Y., Kalinin, P.I., Mitenko, G.V., Alekseev A.O. The role of plant in the formation of the topsoil chemical composition in different climatic conditions of steppe landscape. Plant Soil. 465. P. 453-472. (2021). https://doi.org/10.1007/s11104-021-05019-3