Overview of 30Â years of research on solubility trapping in Chinese karst

Studies conducted over several decades have shown that solubility trapping in karst areas is an important component of the “missing carbon” in the global carbon cycle. Chinese researchers have taken advantage of their natural geography that includes numerous karst areas, representing approximately 1/7 of the global karst area, to conduct studies of solubility trapping. This paper reviews over 30 years of research progress on solubility trapping by China's researchers and summarizes the following five findings: (a) water plays an important role in the karst solubility trapping, regardless of its role as reactant or carrier; (b) the CO2 concentration gradient in the soil environment, which contains biological activity, organic matter content, pH, and temperature, affects the karst solubility trapping; (c) transfer rules for CO2 in the karst system are influenced by different land cover/land use; (d) relationships between biological metabolism and karst solubility trappings are analyzed; and (e) multiple models have been established to estimate the regional and global karst solubility trapping. This review concludes with proposals for future solubility trapping research.