Impact of forest wildfires on components of mountain landscapes of the Baikal region

Abstract

Forest wildfires cover vast territories of mountainous Siberia. As a result, the appearance of the landscape changes completely, as well as the properties of its components. The paper considers the impact of wildfires on the components of the mountain-taiga geosystems of the Primorskii Range, which stretches along the western shore of Lake Baikal. This is the driest area in the Baikal region, with Goletz and mountain-taiga landscapes, coupled with steppe areas. Wildfires regularly occur during hot and dry periods in all zones of the range, especially since 2015. We made landscape descriptions of the territory of the key site and compiled a map of the landscape structure with conflagration fires overlapped with partially and, optionally, completely burnt-out areas. The vegetation cover has suffered the most, and the characteristics of the hydrological regime and the properties of soils have changed. The vegetation is at the initial stage of recovery, and only a few species can be found in the herbaceous-subshrub cover. The characteristics of the water regime, primarily the temperature on the pyrogenically disturbed catchments, undergo significant changes. The mode of mineralization of streams is unstable, and the amplitudes of water level fluctuations are higher due to the destruction of the natural underlying surface of the catchment. The chemical composition of water in streams after wildfires is generally preserved. Although, an increase in the concentration of nitrates and hydrocarbons is possibly due to fires. Pyrogenic destruction of forest ecosystems inevitably leads to the degradation of mountain soils, which are restored over many decades. After fires in soils, acidity and, consequently, the content of organic matter decreases due to their mineralization.