To estimate carbon sequestration potential in the karst area,soil respiration in a natural recovering karst abandoned farmland in Shawan,Puding,Guizhou,southwest China was continuously and automatically monitored for ...To estimate carbon sequestration potential in the karst area,soil respiration in a natural recovering karst abandoned farmland in Shawan,Puding,Guizhou,southwest China was continuously and automatically monitored for more than two years.The results show that the CO2flux of soil respiration(2.63±1.89 lmol m^-2s-^1)is higher in the karst area than in non-karst areas under similar conditions but that regional value(1.32 lmol m-2s-1)is lower because of larger rock fragment coverage(~50%).A the same time,the temperature sensitivity of soil respiration(Q10)in this study area is significantly higher than that of non-karst areas under similar conditions.Soil respiration has an obvious temporal variation,which is reflected in a significant exponential relationship between soil respiration and soil temperature,but the relationship between soil respiration and soil moisture is very complex.Especially soil respiration has an obvious spatial variation,which is likely affected by different diffusion or water-rock reaction processes.展开更多
The karst critical zone is an essential component of the carbon （C） pool, constituting the global C cycle. It is referred to as one of the ＂residual land sink＂ that remains largely in- determinate. Karst area （2....The karst critical zone is an essential component of the carbon （C） pool, constituting the global C cycle. It is referred to as one of the ＂residual land sink＂ that remains largely in- determinate. Karst area （2.2×10^7 km^2） comprises 15% of the world＇s land area, and karst area comprises 3.44~106 km^2 of area in China. Due to the complexity of karst structure and its considerable heterogeneity, C sequestration rate estimations contain large inaccuracies, especially in relation to the different methods used in calculations. Therefore, we reevaluated rock weathering-related C sink estimations in China （approximately 4.74 Tg C yr^-1）, which we calibrated from previous studies. Additionally, we stipulated that more comprehensive re- search on rock-soil-biology-atmosphere continuum C migration is essential to better under- stand C conversion mechanisms based on uncertainty analyses of C sink estimations. Moreover, we stressed that a collective confirmation of chemical methods and simulated models through a combined research effort could at least partially eliminate such uncertainty. Furthermore, integrated C cycling research need a long-term observation of the carbon flux of multi-interfaces. The enhanced capacity of ecosystem C and soil C pools remains an effective way of increasing C sink. Karst ecosystem health and security is crucial to human social de- velopment, accordingly, it is critical that we understand thresholds or potential C sink capacities in karst critical zones now and in the future.展开更多
基金supported jointly by the National Key Research and Development Program of China(2016YFC0502300 and 2016YFC0502102)the United Fund of the Karst Science Research Center(No.U1612441)the National Natural Science Foundation of China(41571130042,41673121,and 41571130074)。
文摘To estimate carbon sequestration potential in the karst area,soil respiration in a natural recovering karst abandoned farmland in Shawan,Puding,Guizhou,southwest China was continuously and automatically monitored for more than two years.The results show that the CO2flux of soil respiration(2.63±1.89 lmol m^-2s-^1)is higher in the karst area than in non-karst areas under similar conditions but that regional value(1.32 lmol m-2s-1)is lower because of larger rock fragment coverage(~50%).A the same time,the temperature sensitivity of soil respiration(Q10)in this study area is significantly higher than that of non-karst areas under similar conditions.Soil respiration has an obvious temporal variation,which is reflected in a significant exponential relationship between soil respiration and soil temperature,but the relationship between soil respiration and soil moisture is very complex.Especially soil respiration has an obvious spatial variation,which is likely affected by different diffusion or water-rock reaction processes.
基金National Natural Science Foundation of China, No.41571130043 Youth Innovation Promotion Association, CAS
文摘The karst critical zone is an essential component of the carbon （C） pool, constituting the global C cycle. It is referred to as one of the ＂residual land sink＂ that remains largely in- determinate. Karst area （2.2×10^7 km^2） comprises 15% of the world＇s land area, and karst area comprises 3.44~106 km^2 of area in China. Due to the complexity of karst structure and its considerable heterogeneity, C sequestration rate estimations contain large inaccuracies, especially in relation to the different methods used in calculations. Therefore, we reevaluated rock weathering-related C sink estimations in China （approximately 4.74 Tg C yr^-1）, which we calibrated from previous studies. Additionally, we stipulated that more comprehensive re- search on rock-soil-biology-atmosphere continuum C migration is essential to better under- stand C conversion mechanisms based on uncertainty analyses of C sink estimations. Moreover, we stressed that a collective confirmation of chemical methods and simulated models through a combined research effort could at least partially eliminate such uncertainty. Furthermore, integrated C cycling research need a long-term observation of the carbon flux of multi-interfaces. The enhanced capacity of ecosystem C and soil C pools remains an effective way of increasing C sink. Karst ecosystem health and security is crucial to human social de- velopment, accordingly, it is critical that we understand thresholds or potential C sink capacities in karst critical zones now and in the future.
