WANG Shijie1,2, LIU Zaihua1,2, NI Jian1,2, YAN Junhua3, LIU Xiuming1,2
(1. State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China;
2. Puding Karst Ecosystem Observation and Research Station, Chinese Academy of Sciences, Puding 562100,China;
3. South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China)
Abstract: The carbon cycle and its processes in the karst area of South China, distinct from other terrestrial ecosystems, are basically clear and show distinctive regional characteristics. The coupling of tectonic background of rain and hot seasons and geomorphic rejuvenation to the solubility of carbonate rocks leads to a large number of carbon sequestration from carbonate rocks re-entering the ecosystem carbon cycle. The dynamic variation of CO2 in the underground space with a binary three - dimensional structure can be regarded as secondary carbon pool, which affects the carbon cycle of the ecosystem. Terrestrial and aquatic plants have the power to use HCO3- carbon source for new ways of photosynthesis. It was found that the coupling effect of carbonate fast weathering and bio-carbon pump on aquatic plants, and the carbon sequestration effect of karst was confirmed. However, there are obvious shortcomings in the carbon cycle study in karst areas of South China. The estimation of carbon sequestration under karst function is challenged by many factors, such as climate change, positive and negative mechanisms of land use change, and exogenous acid. It has also great uncertainties. There are complex multi-interface processes in vegetation, soil, rock, subsurface carbon pool, atmosphere and precipitation. The mechanism of carbon flux and migration is still unclear. Future research should pay more attention to new research methods and technologies aiming at the unique features of karst morphology, the concept of karst critical zone, the long-term observational network, and integration and innovation of karst simulations.
Keywords: Carbon cycle; Karst Region of South China; Carbon sink effect under karstification
EARTH AND ENVIRONMENT Vol.45, No.1, Tot No.315, 2017, Page 2-9
