Isotope variations of 13C / 12C carbon in halophite ecosystems of Barguzin basin

In the article we have studied the isotopic composition of 513С carbon in soils and vegetation of saline ecosystems of Barguzin Basin. The isotopic composition of soil organic carbon (513Corg) is within -19.02 ... -20.29 %o, and composition of vegetation is within -28.31 % ... -28.84 %o. The data obtained indicate the difference in the isotopic composition of vegetation and soil organic matter of surface soil horizons by 8-9 %. The heaving of carbon isotopic composition down the soil profile is associated with the fractionation of carbon isotopes during the respiration of biota, which decomposes soil organic compounds. We also also noticed a high number of various physiological groups of microorganisms - destructors of organic matter throughout the soil profile. A higher content of the studied groups of microorganisms (up to 108 cells / g) was noted in the upper layers of the soil, this was conditioned by the high content of Corg in them (5.62-6.73%). The number of bacteria down the soil profile decreased by 1-3 orders of magnitude.