Natural and anthropogenic transformation of geosystems of Tunkinsky national park: identification and mapping

The paper focuses on the specifics of landscape medium scale mapping employing traditional methods. We selected a key site in Tunkinsky National Park (Republic of Buryatia) and the Tunkinskaya depression located within it and its mountain framing (south of Eastern Siberia) to display the modern structural and dynamic features of the geosystem functioning. The map compiled at a scale of 1 : 100 000 illustrates the differentiation into categories of landscape structures by types of altitudinal-belt conditions of the natural environment, differing in morphological and phytocenotic properties, as well as the nature of natural-anthropogenic transformation. The main factors of landscape discreteness are morphological features of the surface structure of the intermontane territories; the complexes with natural vegetation and their derivative biocenoses, formed as a result of agricultural and pyrogenic transformation, reflected the dynamic nature of the geosystem functioning. The complexes have been formed in river valleys due to debris flows and are assigned to variable states.

Pyrogenic Transformation of Geosystems of the Western Cibaikalia: Factors, Conditions, Current State

The factors of pyrogenic impact on the taiga geosystems of the Western Baikal region against the background of the modern transformation of the global atmospheric circula-tion are studied in the paper. The results of world scientific research on modeling climate change and related adverse weather phenomena (prolonged droughts, thunderstorm activity, etc.) are presented. The natural factors contributing to the increase in the pyrogenic transformation of geosystems are described. The study of the spatio-temporal distribution of fires is carried out on the basis of data from remote sensing of the Earth. Information about unfavorable weather conditions and dangerous hydrometeorological phenomena, data on atmospheric phenomena (thunderstorm activity), daily values of air temperature and soil temperature under natural cover at different depths are analyzed in order to factorial analysis of forest fire sources in the study area. The characteristic of the current stage of geosystems is given based on field research conducted in June 2020. It was revealed that catastrophic fires registered in the study area in 1997 and 2015 occurred against the background of minimal thunderstorm activity. At the same time, in the central part of the Western Baikal region thunderstorms were the leading factor in the 2015 fires. Five years after the fire, the restoration of mountain taiga light coniferous forests is characterized by the predominance of the community of Chamaenerion angustifolium (L.) Scop. The successional dynamics of the geosystems of mountain taiga dark coniferous forests is going through the Betula rotundifolia Spach. with Ledum palustre L. and cereal-forb ground cover. Undergrowth of tree species (mainly pine) is rare and uneven about 800–1200 specimens per hectare.

Post-pyrogenic dynamics of the vegetation cover of the Barskoe raised bog (Vologda Region, Russia)

The study deals with the issues of restoration of peat bogs exposed to the pyrogenic factor. The work was carried out in the Barskoe raised bog, at sites unaffected and directly affected by the ground fire of 2002. A decade later, these sites differed in species composition, phytocoenosis structure, and biomass accumulation rates. Post-pyrogenic changes in the vegetation cover of the raised bog were associated with a slight decrease in species richness, loss of moisture-demanding bog species and an increase of mesophyte’s and xerophyte’s roles, simplification of the mire sites structure towards the loss of complexity, reduction of phytocoenotic diversity, as well as an increase in the dry biomass stocks with a 1.3–1.4-fold decrease in the photosynthetic phytomass and a 6.4–6.7-fold increase in the mortmass. The restoration rate of the mire exposed to pyrogenic transformation can be accelerated by increasing its water table and the prevention of new fires.

Decode space images to monitoring of geosystem pyrogenic transformation

The paper describes the methodology for processing remote sensing data to indicate pyrogenic effects on natural geosystems. Autumn season space images (from the end of the firedangerous period to the beginning of the formation of the snow cover – the end of September to the beginning of October) with a less than 20 % cloud level were preferred. The area affected by fires within Priolhonye in the period since 2013 to 2015 years are analyzed. According to the obtained data it has made more than 200 km2. Pyrogene impact on Priolkhonye geosystems considerably amplifies amidst transforming environmental factors (climate warming, decrease in water level of the Lake Baikal and all that) and anthropogenic impacts, that is lead to change in the structure and rate of physiographic processes. In the conditions of the changing environment of geodynamic active area this impact on Priolhonye geosystems can be disastrous and lead to their irreversible transformation. In particular, disturbed geosystems of cedar forests by fire will could change to pine-larch forests through the birch series. In particular, the destructive effect of the pyrogenic factor on steep slopes with pine-larch rarefied groups of facies leads to the destruction of its invariant structure and replacement by steppe small-graingrassy lithophilic ones.