中文摘要：

针对野外监测面临的岩溶流域边界难以确定以及多种土地利用混杂在一起的问题,在贵州普定建设了不同土地利用条件下岩溶水-碳通量大型模拟试验场,监测研究了不同土地利用条件下的入渗系数和岩溶作用碳汇强度。结果表明,不同土地利用条件下的入渗系数和岩溶作用碳汇强度差异明显,径流强度强烈影响着岩溶作用碳汇强度,模拟裸岩地、荒地、农耕地、草地、灌木地的碳汇强度分别为14.31、12.27、11.79、9.17和12.24 t/（km2·a）。与传统认识不同的发现是,生物量最大的草地,其岩溶作用碳汇强度最小,而裸岩地的岩溶作用碳汇强度最大。这表明：在试验场尺度下,不同土地利用通过改变径流强度和土壤CO2含量这两个因素,对岩溶作用碳汇强度产生影响,且因水化学的恒定行为,径流强度决定碳汇强度,因此在考虑生态系统修复时,不仅需要考虑生物量增加带来的增汇效应,还要考虑到径流强度降低带来的减汇效应。

英文摘要：

High-precision evaluation of the difference in karst-related water-carbon flux variations caused by land use changes is important to the evaluation of water resources and carbon sink after the control of rocky desertification. Since there are difficulties in determining the karst basin boundaries and separating different land uses in a field study,the test site were built to monitor the variations in coefficient infiltration and carbon sink flux under different land uses in Puding of Guizhou. It was found that the coefficient infiltration and carbon sink flux differ dramatically under different land uses and run off dominated in the karst-related carbon sink flux. The carbon sink fluxes of the simulated bare rock land,bare land,farm land,grass land and brush land were14. 31,12. 27,11. 79,9. 17 and 12. 24 t /（ km·a）（ C） respectively. An interesting finding is that the grass land with largest biomass had the minimum karst-related carbon sink flux while the bare rock land had the maximum karst-related carbon sink flux. The results indicate that the land use influences the karst-related carbon sink flux by changing the runoff intensity and soil CO2-induced HCO3-concentration,but the former plays a leading role because of the chemostatic behavior of HCO3-. In conclusion,we note that the decrease effect on the carbon sink caused by the decrease in run off while restoring the ecosystem should be considered although the increase effect on the carbon sink caused by the increase of biomass is taken into account.