Assessment of environment-regulating functions of geosystems at the local level

Abstract

Within the framework of landscape planning methodology, for the first time, an assessment of the environment-regulating functions of the geosystems of the river basin Bol. Mamai (south-eastern coast of lake
Baikal, Khamar-Daban range, Buryatia) was carried out. A landscape-typological map at the level of facies
groups on a scale of 1: 50,000 was the basis for the study. Data on organic carbon storage in tree phytomass and upper humus horizons of soils at a depth of 0-5 cm were used as quantitative indicators of the climate-regulating function of geosystems. To assess the runoff-forming and erosion-regulating functions, data on tree
phytomass and flow accumulation indicators, and the LS factor calculated from the DEM were used. The functions were assessed for each type of geosystem using methods of GIS-analysis and landscape-interpretive mapping. A matrix of the importance of geosystems for providing environment-regulating functions has been compiled. As a result, it was revealed that the mountain dark coniferous taiga (30.6%) and subalpinotype mountain-meadow geosystems (26.2%) have greatest distribution in the drainage basin of Bol. Mamai river. Valley geosystems occupy about 12%. The greatest contribution to environmental regulation is made by indigenous dark coniferous (fir, spruce-fir and fir-cedar) forests, which are widespread both in the mountainous part of the basin and in the foothills, but in the latter their share has been significantly reduced due to anthropogenic activities. The developed criteria for assessing the environment-regulating functions of geosystems can be applied to other territories.