【摘要】 以桂林丫吉村岩溶试验场为例,研究了湿润亚热带峰丛洼地表层岩溶带生物量碳库、凋落物碳库、土壤有机碳库(SOM)及其活泼性、有机碳分解速率、土壤中CO2浓度和土壤呼吸CO2排放,表明岩溶系统中丰富的碳库提供了系统中CO2的来源,并用δ13C证实春夏岩溶活跃季节中岩溶输出C约60%来自土壤CO2.由此认为,驱动岩溶作用的CO2并非直接来自大气CO2,而是大气植物土壤水碳素转移的结果,因而揭示了土壤作为碳环境地球化学界面对于表生带岩溶作用的驱动意义.更多还原

【Abstract】 Taking Guilin Yaji Karst Experiment Site as an exemple and with the methods of field monitoring and laboratory analysis,this paper studied the distribution and transferring of carbon in the karst soil system of peak forest depression in the humid subtropical region of China.The carbon pools in biomass,litters and soil organic matter(SOM)and their mobility as expressed by oxidizability and decomposition rate of SOM,the concentration of soil CO\-2 and the emission rate of CO\-2 from soil were investigated.The mobile carbon pool in the system supplied a rich source of CO\-2,which drived the karst process.When active karst process happened in Spring and Summer,over 60% of carbon in the output water was derived from soil CO\-2,as traced by δ 13 C distribution in the system.Therefore,owing to the carbon transfer in the pathway of air plant soil water,karst process took place rather under soil rock water interface than under air rock water interface.Thus,the epigenetic karst process was driven and accelerated by soil as an interface of carbon environmental geochemistry.更多还原