苔藓结皮对碳酸盐岩的风化作用研究进展

Research progress on the effect of moss crust on the weathering of carbonate rocks

岩溶地区碳酸盐岩裸露率高、土壤形成速率缓慢,是世界上石漠化最严重的地区之一。在岩溶石漠化地区,苔藓植物与裸露钙质岩石上的藻类、细菌和真菌共存,形成苔藓结皮。苔藓结皮依赖其独特的形态结构、生理生态和遗传机制在干旱贫瘠的岩石上生长,参与碳酸盐岩的风化、土壤的形成和发育,对岩溶地区退化生态系统的恢复具有不可替代的作用,被誉为“荒漠生态系统工程师”。文章尝试阐明苔藓结皮各组分(微生物、苔藓植物)参与的岩石风化成土过程以及在石漠化治理中的应用,为岩溶区石漠化治理提供理论依据。

The exposed area of carbonate rocks in the karst region of Southwest China reaches 550,000 km2,which is the largest area with the most developed karst in the world and also the most severely desertified area in the world.Therefore,the origin of soil in karst ecosystems and the process of carbonate rock weathering have always been scientific issues of great concern.Mosses coexist with algae,bacteria,and fungi on the exposed calcareous rocks,forming a moss crust.The moss crust can not only survive and reproduce on the surface and crevices of rocks under severe conditions of water shortage and nutrient deficiency,but also accelerate the weathering of carbonate rocks through organic acid secretion,CO2 release,and mechanical action.The accumulated organic matter can develop the soil parent material on the surface of carbonate rocks into shallow primitive soil,playing an irreplaceable role in the restoration of degraded ecosystems in karst regions,and is known as"the engineer of desert ecosystem".Among the components of moss crust,the volume of microorganisms is at the micrometer scale,and people's understanding of the microbial population growing with moss on rocks is mainly obtained through morphological observations.Many microorganisms are too small to be cultivated,so it is impossible to obtain information on the entire microbial population in this habitat,and thus their functional knowledge has been ignored.Therefore,in order to provide a theoretical basis and technical support for ecological management in desertification areas,this article summarizes the previous studies on moss crust in recent years in desertification areas,clarifies the rock weathering and soil formation process in which various components of moss crust(microorganisms and moss plants)participate,and their application in desertification control.