Based On The Form Of Geochemistrycharacter Of Inorganic Carbon In Hulun Lakes

Hulun Lake is located in semi-arid temperate zone and continental climate with high latitudes, which is the largest freshwater lake in the central of arid region in Asia, it has been included in the List of emphasis of wetlands in international and accepted as World Biosphere Reserve by UNESCO. It is not only the important fishery of freshwater waters, also the largest comprehensive nature reserve mainly to protect the grassland, wetland systems and rare endangered birds in northeastern China. Hulun wetlands and Daxinganling forest build the ecological barrier of northeast even north in China together. So, it has occupies an extremely important position to examine the sources and sinks of carbon and to calculate carbon balances, which is still blank research in the area lake wetland ecosystem carbon cycle.This study was carried out on the Hulun Lake (HLH) in which eastern Inner Mongolia Plateau based on its inorganic carbon form, to study geochemical characteristics of inorganic carbon sediment in lake. The combination of investigation and laboratory experiments to simulate the patter of horizontal distribution of dissolved inorganic carbon (DIC), total inorganic carbon (TIC), dissolved organic carbon (DOC) and total organic carbon (TOC) in overlying water and the form distribution of inorganic carbon (IC) in sediment of the lakes are studied. Meanwhile, the form transformation of IC and their potential amount contribution to carbon cycling and the sequestration capacity of carbon in sediment, and the DIC fluxes across water-sediment interface in lakes are also discussed. Basic information and scientific evidence was accumulated for the carbon cycle of lakes in the high-latitude regions of our country and protection of the reasonable development and use of available for lakes in Inner Mongolia Autonomous Region.The results are described as follows:1. The form of five IC Lake sediments was NaCl form, NH3·H2O form, NaOH form, NH2OH·HCl form and HCl form. The dominant forms of IC in sediment from HLH are NH2OH·HCl form and HCl form indicating that calcite and aragonite, which are the main source of IC, are the dominant carbonate minerals in the lake sediment.2. The potential amount of IC forms contribution to carbon recycling rank as: NH2OH·HCl form>NH3·H2O form>NaOH form>NaCl form. The contributions to carbon cycling of IC forms rank as:NaOH form>NH3·H2O form>NH2OH·HCl form>NaCl form>HCl form.3. Simulation study shows that the sediment release of about 6.9×105t of DIC to overlying water of Hulun within 90 days in summer, which provide a lot of carbon for the photosynthesis of submerged plants in lake.4. The fixed amount of IC about Hulun sediments for NaCl form, NH3·H2O form, NaOH form, NH2OH·HCl form and HCl form annual were 0.14×1011,0.73×1011, 0.37×1011,2.08×1011 and 1.99×1011 g C/yr, and total IC fixed amount of 5.31×1011gC/yr.5. The ability of different forms of IC participate in the recycling carbon related to activity of the five forms and the control of the natural environment in lake water, also, the percentage content of the five forms of IC occupies total IC determine the contributions to carbon cycling of different IC forms directly.