Ecological and geographical patterns of soil distribution and soil resources of the central ecological zone of Baikal region (the Republic of Buryatia)

Based on the results of many years' research and unified methodological and classification approaches we have studied the ecological and geographical patterns of soil distribution in the Central Ecological Zone (CEZ) of Baikal region (the Republic of Buryatia) and drawn a map of soil cover. At this stage of research, we have identified 38 soil types combined in 18 soil contours, determined their territorial distribution and estimated the soil resources area. The dominant effect of vertical zoning in spatial distribution of soils is associated with the mountainous topography of the studied region. It has been established that the soils of the mountain-tundra zone occupy a significant territory of 11,120 km2, or 29.3% of the total area. They are mainly represented by raw soils - lithozems and petrozems with associated soils and taiga gley cryogenic soil with boggy gley soil and boggy lithozems. We also have found membranous “soil-like” bodies. Most of the studied area (53.8% of the total) is occupied by the soils of middle mountains, where parapodzols, burozems, sod-parapodzols, podzols, sodpodzols, raw-humus burozems etc. prevail. Dark humus, humous-dark humus, peat-cryozems, gleic peat-podburs etc. are met. A significant part of podburs in the soil cover of middle mountains is associated with the calc-alkaline Angara-Vitim batholiths preventing eluvial soil differentiation, and burozems - with the development of “warm” landscapes influenced by warming affect of the Lake Baikal waters. In low mountains podzols and gleic sod-podzols with accompanying sod-podzols and sod-podzolic-gley soils are dominant, they occupy 34 km2, or 8.9% of the total area. In intermountain basins, gray metamorphic soils, sod-podburs and sod-gray soils prevail, as well as humus psammozems, they occupy 594 km2 in total. Podzols and podburs with a slightly differentiated profile associated with the high prevalence of calc-alkaline dominate under the automorphic conditions in the northern and northeastern parts of the studied area. Sod-podzolic soils are common both for the plain and foothill zone of the Lake Baikal eastern coast. Dark humus and gray humus soils, which occupy a small part of the Central Ecological Zone (CEZ) are confined to the outcrops of marbles and their derivatives. Various complexes of alluvial soils are developed in the floodplain-delta landscapes and at river mouths, and peat eutrophic soils, peat-gley soils, etc. - on wetlands and bogs. Gleic dark humus and peat eutrophic soils are mainly developed on lakesides. In general, the share of bog and alluvial soils account for 2,405 km2 (6.3% of the CEZ total area). Saline soils occupy small places: they are found only near mineral springs.