Features of the bog formation process in the Northern Trans-Urals

The work examines the stages of development of swamps in the Northern Trans-Urals in the Holocene based on paleoecological methods of studying peat deposits and radiocarbon dating. The conducted research made it possible to reconstruct in detail the history of the development of swampvegetation in the Northern Trans-Urals, to identify catastrophic events that led to the change of plant communities in the marshes and to link them with time. Three bog massifs were selected as objects of study: Troitsky, Bolshoy Sosnovy and the Khorpiya peat outcrop in the Lozva River valley. It is shown that the processes of swamping in the Northern Trans-Urals began at different times. Peat accumulation began in the Troitsky peat bog about 8.0 thousand years ago, in Bolshoy Sosnovyy – about 5.7 thousand years ago, in the floodplain of the Lozva River (Khorpiya section) – about 5.4 thousand years ago. The main routes of swamping can be considered to be dryland swamping of forests in low-lying areas of the relief and swamping of postglacial lakes. When lakes (Bolshoye Sosnovoe and Troitskoye) become swamped, peat formation begins with a transitional stage, with the overgrowing of shallow waters with cotton grass and sphagnum mosses. When a spruce forest becomes swampy under conditions of stagnant waterlogging (Khorpiya peat bog), peat formation begins with the accumulation of wood peat. The stages of development of the vegetation cover of swamps are determined by climate change. During periods of cold weather and freezing of peatlands, woody plants disappear, and instead, oligotrophic sphagnum mosses begin to expand.