Wetlands of International Importance "Lakes Tobol-Ishim forest steppe" was organized in 1996 on the area of 1217 thousands hectares. They are one of the key ecosystem types that perform a number of important ecological, economic, and resource functions for the conservation of biological diversity in the south of Western Siberia.
Landscapes represent a complex of sites of small-leaved aspen-birch forests with agricultural lands on the spot steppe meadows and meadow steppes. A characteristic feature is the presence of a many of lakes that differ in size, shape, origin and degree of mineralization of water. Eutrophic swamps with inclusion raised bogs, alkaline meadows, saline are also common. According to the research high bogs began to form in Subboreal-Subatlantic periods of the Holocene. Beginning of formation water meadow dates from the early to mid subboreal period. Low-power peat deposits were formed at the beginning of Subatlantic period of the Holocene. Upland peat bogs have similar stratigraphy. Lake sediments often are placed at the basis, then a layer of lowland peat goes, which is replaced by high peat, sharply or gradually, through a horizon transitional peat. Capacity of the individual horizons may differ due to local factors that determine the rate of peat accumulation.
The average rate of vertical growth of peat in Subboreal-Subatlantic of Holocene period, calculated from the radiocarbon dates obtained from peat bogs and water meadow of Tobol-Ishim forest-steppe, is 0.8 mm / year. The rate of growth of peat is not constant and can change considerably in the separate time intervals. The linear equation dependence vertical growth of peat, built according to more than 80 radiocarbon dates from peat bogs has the form y = 9,6657x + 276,51 (R2 = 0,81). Maps of average and maximum power of marshes of different types are constructed according to available data.
Geochemical characteristics some of peat bogs were investigated to assess the biogeochemical conditions in the different periods of the Holocene, to identify local, regional and global signal of anthropogenic environmental impact. They reflect the different temporal features organo-accumulation of soil formation, biogeochemical migration of the elements, climate change and vegetation during the Holocene, as well as the specifics of the modern stage of formation of peat.
The database of swamps from 1980 to 2009 is created for an assessment of the current trends of areal variability for the territory of a subtaiga and forest-steppe zone of the South of the Tyumen region. Cartographical sources occurring at different times, data of remote sensing, satellite images from the LANDSAT 5 TM satellite were processed and analyzed in the program MapInfo 10 complex. Maps of trends water logging were compiled on the basis of research. The positive dynamics of the formation of swamps is observed in all studied territory. On average 3.1 km2 of water logging of area accounts for each key sector. An average annual growth makes 0.63% of the area of wetland.
*The study was supported by a project of the Tyumen State University aimed at executing Resolution 220 of the Government of the Russian Federation, and the Russian Foundation for Basic Research (project no. 14-05-00956-a)