Microbial mechanism on distribution, renewal, and maintenance of soil organic carbon pool in karst area

Abstract:

Attributing to the water-carbon dioxide-carbonatite-organism interaction, carbon cycle in karst area is active and 8.24×108 t C/a of karst carbon sink has been formed all over the world, which accounts for 29.4% of the global missing sink. Some karst carbon sinks are stored in the form of soil organic carbon. Therefore, alkaline soil carbon sequestration is expected to be the main way of carbon neutralization. Microorganisms, the important drivers of soil carbon cycle, play an important role in mediating the balance of plant compounds and microbial necromass in soil. This paper reviewed the reserves, composition, and sources of karst soil organic carbon pool, microbial factors affecting the dynamics of karst soil organic carbon pool, and the microbial mechanism on renewal of karst soil organic carbon pool. Moreover, the effects of microorganisms on plant compounds and microbial necromass in karst soil were discussed and the key problems were put forward. This review is expected to help understand the microbial mechanism on the distribution, renewal and maintenance of karst soil organic carbon pool and deepen the understanding of karst soil carbon cycle and its microbial mechanism. In addition, it provides strategies for China to cope with the challenges on Four Per Mille Initiative: Soils for Food Security and Climate.