Carbon Cycle Characteristics in Karst Cave System of Xueyu Cave from 2012 to 2013
Ren Kun
Shen Licheng
Yuan Daoxian
Wang Xiaoxiao
Xu Shangquan
Abstract：The high CO2 concentration in Xueyue cave,Chongqing,is rare at home and abroad.However,the circulation char-acteristics of carbon and its controlling factors in this cave system remain unknown.P CO2-soil ,P CO2-cave ,P CO2-eq ,SIc,andδ13 CDIC of subterranean stream were analyzed to investigate the laws of CO2 concentration variations in Xueyu cave and its contolling factors,as well as the impact on carbon cycle in this cave by subterranean stream.It is found that soil P CO2 mainly controlled by precipitation in subtropical areas was higher in rainy season than that of dry season.Cave air P CO2 exhibited seasonal variations, high cave air P CO2 typically occurred during warm periods,and low cave air P CO2 were typical of cold periods.It was ventilation driven by the temperature difference between cave and outside air that resulted in a sharp transition of cave air P CO2 .Mean-while,cave air P CO 2 could rise to high level in a short period of time because of CO2 degassing from subterranean stream.Due to soil CO2 effect,groundwater became more mineralized water with low SIc and high water P CO2-eq ,and dissolution in some months in rainy season.With the reduction of soil CO2 and precipitation,groundwater had low degree of mineralization with high SIc and low water P CO2-eq in dry season.
Keywords：karst cave systemcarbon cycleCO2 partial pressurecalcite saturation indexXueyu caveclimate change
Publication Date：2016-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：11( 1424-1434 )