Experimental Studies, Modeling, and Mapping of Natural Functions of the Steppe Landscapes Near Lake Baikal

Abstract

The results of complex landscape studies of the extra-zonal steppes of the Priolkhonsky plateau (Irkutsk Region, Russia) are presented. In the past century, this territory exposed to significant agricultural transformations, and in addition since the second half of the 20th century, recreational activities began to actively develop in the coastal zone. A review of the experimental methods used in the work to assess the geosystem functions: phytomass accumulating and erosion regulation is given. Based on the geosystem approach, results of experimental observations are extrapolated to other parts of the landscape, and maps of productivity and susceptibility to water erosion were made. Based on the results of experimental and mathematical modeling, environmental factors affecting the functioning of geosystems in the context of modern economic use of steppe landscapes are identified. Low values of herbaceous phytomass stocks (from 0.3 t/ha to 3.2 t/ha) were found out. The relative rating of different types of locations by the transferred silt (vary from 54 to 245 g/m3) was made based on experimental studies of wind erosion. The results of multiple regression showed that the main landscape factors that positively affect wind erosion are: the quantitative ratio of the fractions of the mechanical composition of the upper horizon of the soil (the positive relationship with silt and dust is most often) and the steepness of the slope; and the negative relationship is most pronounced with rockiness of soil and projective cover of herbaceous vegetation. Under arid conditions, which influenced the formation of dry depressions and the concentration of loess and sandy sediments in them, the development of denudation processes is primarily due to natural factors and increases by anthropogenic impact.