| The international geosphere-biosphere program(IGBP),which was brewed and implement by the international federation of science(ICSU)in 1980s,was a major international scientific plan.Land Cover/Land Use(LUCC),which has great influence on the terrestrial ecosystem carbon storage and carbon cycle,has became a hot issue of global change research.The ecosystem of Mining area was different from the natural ecological system,with special structure and function of the organic integrity,in the process of frequent material recycle,energy flow,and information transmission.The production activities in the mining areas,especially the high intensity of mining,will inevitably lead to the change of land use pattern and unbalance of carbon cycle.Therefore,The study on soil organic carbon,aggregate-associated carbon and special carbon cycle research in the mining area has significant importance.Panji coal mining area in Huainan was selected as the research object.The seasonal changes of soil organic carbon,microbial biomass carbon and dissolved organic carbon were studied by outdoor sampling and laboratory experiments,and to explore the effects coversoil thickness and vegetation type on soil organic carbon,and in order to provide basic data for the study of carbon cycling in Panji mining area.The results were a follows:(1)Soil organic carbon,microbial biomass carbon,dissolved organic carbon content of ecological remediation areas was lowed than that of the surrounding natural soil.Organic carbon content of Panyi ecological remediation areas was basically higher than that of Dongchen ecological park(except for November 2015),and it was also found that the trend of soil organic carbon in the study area was consistent with the vegetation growth trend in the restoration area.(2)soil organic carbon content with different thickness of covering soil varied respectively from 5.56 to 9.31 g/kg,soil organic carbon content with the top-soil depth of 0-20 cm was 9.31 g/kg,and was respectively 23.91%?2.35%?26.31%?45.43%higher than that of 20-40 cm,40-60 cm,80-100 cm.This may be due to the influence of vegetation types on soil organic carbon in the reclamation area.(3)In ecological remediation areas,the composition proportion of the mechanical stable aggregate was distribution in shape of "W" with decreasing size fraction,the percentage of>3.2 mm size fraction accounted the largest proportion and existed significant difference from those of other size fraction(P<0.05),the composition proportion of the water stable aggregate similar to the mechanical stable aggregate.Mean weight diameter of soil water stable aggregate at ecological remediation areas were less than the control area,and was respectively 0.82 mm and 0.67 mm,and that of the top-soil depth of 60-80cm were significantly higher than that of other areas.(4)The content of organic carbon at ecological remediation areas were less than the control area,and respectively 24.97%and 35.1%,and the water stable aggregate in each size fraction also less than the control area.The content of soil organic carbon under different thickness of covering soil was a single peak distribution The content of soil organic carbon in each size fraction of 40-60 cm and 60-80 cm thickness of covering soil were higher than that of other thickness of covering soil.(5)With different thickness of covering soil,the sequence of Hu Min acid was:0-20 cm>20-40 cm>40-60 cm;The sequence of fulvic acid was:40-60 cm>20-40 cm>0-20 cm;The sequence of humic substance was:40-60 cm>20-40 cm>0-20 cm.In the formation of humus,the soil organic carbon,soil water content and total nitrogen played an important role. |
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