Home – Home – Jornals – Geography and Natural Resources 2022 number 3

This paper presents the results of a large-scale soil-geobotanical profiling of phytocoenoses at the contact of different environments in the Baikal region. We obtained evidence which is responsible for the spatial stratigraphy and trends in the formation of vegetation at the regional level of its organization. We identified the pattern of alternation of forest and steppe cenoses in conditions of extrazonality of steppes in the central part of the western shores of Lake Baikal (Priolkhonie) and in the middle part of the bottom of Barguzin depression. It was established that there are no clear floristic and cenotic links of vegetation with edaphic conditions where both steppe and forest communities occur on the same soils. Forestation of territories occupied by steppe cenoses is observed everywhere. Vegetation forming at the contact of forest-steppe and zonal steppe (Selenga river basin) is characterized by an alternation of forest and steppe cenoses according to topographic features with a clearly pronounced link with the types of soils characteristic for the zones at the contact between forest-steppe and zonal steppe. Forestation of steppe territories occurs within a zonal forest-steppe, and tree species encroach on the zonal steppe with the spatial expansion of the interzonal ecotone. In conditions of altitudinal zonality (surroundings of Davan Pass, Baikal Ridge), there occurs a gradual transition from one altitudinal zone to another - forest to subgoletz, and subgoletz to mountain tundra - due to invasion of tree species into the cenoses at the contact of the zones (interaltitudinal-zonal ecotones). Cenoses form on the same soil. Such investigation can serve as the methodological basis for indication of vegetation development in the Baikal region as a whole.