Carbon Fluxes and Sinks:the Consumption of Atmospheric and Soil CO_2 by Carbonate Rock Dissolution  

作　　者：CAO Jianhua YUAN Daoxian Chris GROVES HUANG Fen YANG Hui LU Qian 

机构地区：[1]Institute of Karst Geology,CAGS,Karst Dynamics Laboratory,MLR and Guangxi,Guilin 541004,China [2]International Research Center on Karst,UNESCO [3]International Research Center on Karst,UNESCO,Guilin 541004,China [4]Western Kentucky University,Bowling Green KY 42101,USA

出　　处：《Acta Geologica Sinica(English Edition)》2012年第4期963-972,共10页地质学报（英文版）

基　　金：supported by the National Natural Scientific Foundation of China(Grant No.40872213);the projects from the China Geological Survey(Grant Nos. 1212010911062 and S-2010-KP03-07-02);from the Ministry of Land and Resources(Grant No.201211086-05);IGCP 598:Environmental Change and Sustainability Karst Systems

摘　　要：Carbonate rock outcrops cover 9%-16% of the continental area and are the principal source of the dissolved inorganic carbon （DIC） transferred by rivers to the oceans, a consequence their dissolution. Current estimations suggest that the flux falls between 0.1-0.6 PgC/a. Taking the intermediate value （0.3 PgC/a）, it is equal to 18% of current estimates of the terrestrial vegetation net carbon sink and 38% of the soil carbon sink. In China, the carbon flux from carbonate rock dissolution is estimated to be 0.016 PgC/a, which accounts for 21%, 87.5%-150% and 2.3 times of the forest, shrub and grassland net carbon sinks respectively, as well as 23%-40% of the soil carbon sink flux. Carbonate dissolution is sensitive to environmental and climatic changes, the rate being closely correlated with precipitation, temperature, also with soil and vegetation cover. HCO3 in the water is affected by hydrophyte photosynthesis, resulting in part of the HCO~ being converted into DOC and POC, which may enhance the potential of carbon sequestration by carbonate rock dissolution. The possible turnover time of this carbon is roughly equal to that of the sea water cycle （2000a）. The uptake of atmospheric/soil CO2 by carbonate rock dissolution thus plays an important role in the global carbon cycle, being one of the most important sinks. A major research need is to better evaluate the net effect of this sink in comparison to an oceanic source from carbonate mineral precipitation.Carbonate rock outcrops cover 9%-16% of the continental area and are the principal source of the dissolved inorganic carbon （DIC） transferred by rivers to the oceans, a consequence their dissolution. Current estimations suggest that the flux falls between 0.1-0.6 PgC/a. Taking the intermediate value （0.3 PgC/a）, it is equal to 18% of current estimates of the terrestrial vegetation net carbon sink and 38% of the soil carbon sink. In China, the carbon flux from carbonate rock dissolution is estimated to be 0.016 PgC/a, which accounts for 21%, 87.5%-150% and 2.3 times of the forest, shrub and grassland net carbon sinks respectively, as well as 23%-40% of the soil carbon sink flux. Carbonate dissolution is sensitive to environmental and climatic changes, the rate being closely correlated with precipitation, temperature, also with soil and vegetation cover. HCO3 in the water is affected by hydrophyte photosynthesis, resulting in part of the HCO~ being converted into DOC and POC, which may enhance the potential of carbon sequestration by carbonate rock dissolution. The possible turnover time of this carbon is roughly equal to that of the sea water cycle （2000a）. The uptake of atmospheric/soil CO2 by carbonate rock dissolution thus plays an important role in the global carbon cycle, being one of the most important sinks. A major research need is to better evaluate the net effect of this sink in comparison to an oceanic source from carbonate mineral precipitation.

关 键 词：carbonate rock carbon transfer carbon flux and sink exchange between inorganic carbon and organic carbon 

分 类 号：S181[农业科学—农业基础科学]