岩溶土壤有机碳库分配、更新及其维持的微生物机制

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

摘要:

在水-二氧化碳-碳酸盐岩-生物的相互作用下，岩溶碳循环活跃，在全球形成8.24×108 t C/a的岩溶碳汇，约占全球遗漏汇的29.4%，其中部分岩溶碳汇以土壤有机碳的形式固存，因此碱性土壤固碳是未来碳中和的主要途径。微生物作为土壤碳循环的重要驱动者，影响着土壤有机碳主要赋存形式即植物残体碳与微生物残体碳的动态变化。本文通过综述岩溶土壤有机碳库储量、岩溶土壤有机碳库的来源与构成、影响岩溶土壤有机碳库动态的微生物因素以及岩溶土壤有机碳库更新的微生物机制，探讨了微生物对岩溶土壤植物残体碳与微生物残体碳的影响，并提出亟待解决的关键科学问题。这为深入研究岩溶区土壤有机碳库分配、更新及其维持的微生物机制，深化对岩溶土壤碳循环及其微生物机理认识，进而为应对千分之四全球土壤增碳计划提供了参考。

关键词:岩溶;土壤有机碳;微生物作用;植物与微生物残体

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.

Key words:karst;soil organic carbon;microbial effect;plant-and microbial-derived compounds