Study On Soil Carbon Stock And Its Spatial Distribution, Influence Factors In The Forest Of China

Soil carbon cycle and carbon sequestration research is one of the spots in the current terrestrial ecosystem carbon and global researches . The soil organic carbon reserves is the main sources and sinks of global greenhouse gas . As the basement of human existence and development, soil is vulnerable to human activities . The rapid reponse of atmospheric environment and terrestrial acosystems may be caused by the minor change of the soil carbon . The research on land soil carbon stored status and the carbon cycle process control and feedback mechanisms , is the basement of forecast atmospheric CO₂ levels and global climate change , is the basis for the use of land resources and the mitigation of greenhouse . Forest soil play an important role in the global carbon cycle . The investigation to the forest soil carbon reserves conducive to evaluat accurately the status of the forest soil carbon storage in the global carbon cycle , also conducive to the calculation of the global atmospheric carbon balance .Current researches on forest ecosystem soil carbon storage are reviewed in this paper . The forest soil carbon reserves of China has been estimated by the use of soil sampling data in exiting literature , field data , 1:400 000 types of soil map and The distribution of natural forests and plantations of China . The vertical and space distribution of soil carbon density were analysised with the temperature , rainfall , elevation, vegetation and soil nutrient and texture .In this paper, the main results are brought forth as follows :(1) . The vertical distribution of froest soil organic carbon in China . Base on the soil profiles database of forest in China , the vertical distribution of soil organic carbon was studied . The main organic carbon stored in the 0～20 cm soil , with the increasing depth , organic carbon reserves decreased , more obviously in 0～40 cm . The differences were showed in different categories comparison .(2) . The characters of forest soil carbon pool in China . With soil profiles database of forest in China , 1:400 000 types of soil map , the forest district map and the map of forest area of China , the total area of natural forests and plantations in China is 169.0163×l0⁶hm² . The total carbon storage is 208.45×10⁸t, the average bulk density is 12.33 Kg/m² , China's forest (natural forests and plantations) area of China's land area (not calculated in Taiwan and the South China Sea islands) 19.26 % , its organic carbon reserves of the nation's mainland land soil organic carbon reserves of 22.56% .(3) . The distributing patterns of forest soil carbon pool in China . Temperature differences caused by latitudes change and rainfall differences caused by longitude have great impact to the forest soil organic carbon density in China . The region which the higher forest soil organic density distributed were (E80°～98°,N27°～36°)and (E120°～133°,N39°～50°) . Respectively from the two region to east or south , there's a significantly decreasing trend in forest soil organic carbon density .(4) . Major factors affecting forest soil carbon storage in China . Study on the correlation between foreset SOC and temperature , precipitation and soil characters was carried out in this paper . Soil carbon density increased with the precipitation , elevation and total nitrogen , but decreased with temperature , there's a certain negative correlation between the PH and soil organic carbon content , but not obvious ; forest soil organic carbon content decreased with the density increasing .