Estimation Of the raised bogs peat deposit transformation of West Siberia South-Eastern Part

The estimates ambiguity of the consequences of both mires drainage and restoration in terms of greenhouse gas emissions and the rate of modern peat accumulation, potential fire hazard, and biodiversity dynamics makes it necessary to conduct research on the current state and trends of self-recovery of biosphere functions of drained raised bogs in the southern taiga subzone of West Siberia. The goal of this work is to assess the intensity of peat accumulation and the degree of transformation of peat deposits within the drained raised bogs the South-Eastern part of West Siberia based on the analysis of the physical properties and botanical composition of peat. The objects under study are 8 key sites in drained and similar natural pine-shrub-sphagnum raised bog. The species composition is characterized by the dominance of Pinus sylvestris, Ledum palustre, Chamaedaphne calculata and sphagnum mosses. The area under study were drained in 1980 by a network of open channels for the purpose of forest melioration and peat extraction. The lack of planting and repair of the drainage network has led to the development of self-recovery processes in drained mires. Field studies of the sites included the access of peat deposit depths, selecting stratigraphic layer by type and degree of decomposition of peat by visual method; sampling peat in steps of 5 cm to a depth of 90 cm using a Russian peat corer. Laboratory analysis of peat included determination of the following characteristics: Botanical composition, degree of decomposition, ash content, water content, bulk density. We take analyzed a total of 162 peat samples. The significance of differences in the physical properties of peat in drained and natural bogs was assessed using the Mann-Whitney test (U-test). Classification of sites by criteria of physical properties of peat was performed by cluster analysis. The consequences of drainage are manifested in a change in the species composition of mosses and an increase in the proportion of wood residues in the peat deposit upper layer. On two sites, the change of balticum and magellanicum peat to fuscum peat at a depth of 25 cm was noted. The other site is characterized by the appearance of upper layer of green mosses in the peat composition with a maximum share of their presence at a depth of 15-20 cm. Two sites are characterized by the formation of wood peat in the upper layer, with almost complete absence of sphagnum moss residues here, which can be an indicator of the almost complete absence of the process of peat deposits modern accumulation. As a result of the study, it is shown that the bulk density of peat characterizes the rate of accumulation of peat and is directly related to the ash content and the degree of decomposition. The increase in density in the peat layer at depths up to 25 cm corresponds to the period of peat accumulation during the maximum effect of drainage. The change in ash content with depth and a maximum value in the layer of 15-35 cm is an indicator of the transformation of the peat layer located on the surface during the first years after drainage, and is generally consistent with the laws of bulk density changes in depth. According to the results of the study, it was found that the peat layer formed after drainage reclamation changes from 0 to 25-30 cm in different key sites. In 6 of the 8 studied sites, the process of modern peat accumulation is observed; in two sites, the rate of peat accumulation is minimal or completely absent.

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