岩溶生物地球化学研究的进展与问题

在CO_2-水-碳酸盐岩活跃的代谢体系中,由于参与岩溶作用过程的二氧化碳来源复杂,因而研究碳酸盐岩环境中二氧化碳在生物介导下所耦联的物质循环过程及其与全球变化的关系成为岩溶生物地球化学学科的主要内容,并使其成为现代岩溶学的重要分支。在分析国内外岩溶学、地球化学、生物学等交叉学科研究成果的基础上,本文简要评述了基于岩溶生物地球化学特性的水土流失与石漠化过程,碳酸盐岩矿物在生物作用下的化学风化、元素释放规律以及控制元素循环的界面过程,碳酸盐岩区土壤-大气界面下的气体循环及其控制因素和过程,碳酸盐岩区有机污染物在环境中的来源、分布规律与降解,微型生物在岩溶水体碳循环过程中的作用等主题的主要研究进展和存在的科学问题。因此,需要以CO_2为核心把岩溶环境中不同尺度上生物有机体参与的地球化学过程联系起来,但人们对生物有机体是如何通过协同作用而改变岩溶环境的,还了解得很少。如果能查明碳酸盐岩一土壤一水一生物相互作用产生的功能,岩溶生物地球化学将进一步拓展CO_2-水-碳酸盐岩相耦合的岩溶作用过程,并在岩溶资源领域和全球变化领域有广阔的应用前景。因此,岩溶生物地球化学需要多学科的协同研究,特别是加强生物过程与岩溶过程的耦合研究,方能解决岩溶领域存在的生态环境问题。

Perspectives on karst biogeochemistry

In the karst process, the dissolution of the carbonate minerals, such as CaCO3 and CaMg(CO3)2, is essential in the presence of water and under a normal atmospheric temperature/pressure environment, involving the consumption of atmospheric CO2 into Ca2+/Mg2+ and the anion bicarbonate. Usually, the hydration of CO2 to HCO3- is relatively slow, especially in the forward direction, of which the CO2 are originated from different sources resulting from a complex interaction between geology, climate and hydrology, and also biological components. In this paper, previous researches in the fields of karst, geochemistry and biology were overviewed. The main points of this paper are to address the issues on karst biogeochemistry process, the biological action involving chemical weathering of carbonate rocks and element cycle, the gas circulation in the interface between soil and atmosphere, organic pollutants in the karst environment, as well as the function of microorganism relating to karst carbon cycle, with a major focus on water-soil erosion and rocky desertification. To understand the above problems, the function of earth creatures in the karst environment must be valued.