中国西南岩溶关键带结构与物质循环特征

岩溶关键带调查研究的目标是揭示岩溶生态系统的动态平衡和演化机制,旨在为经济社会提供资源环境服务的可持续管理对策,指出在合理的人为活动下增强岩溶关键带韧性的办法及修复受损部位的有效途径。碳酸盐岩作为可溶岩,赋予了岩溶关键带在结构上及物质循环过程中的岩石圈-生物圈相互作用等方面的若干特殊性。该文以中国西南岩溶区为例,总结了诸多学者的研究成果,揭示了从桂林岩溶区到重庆武隆岩溶区,岩溶关键带发育厚度由几米逐渐增厚至1 000 m的区域差异; 岩溶关键带的垂向物质循环过程以土壤-表层岩溶带为中心环节,而在横向上则呈现“岛屿状”镶嵌分布特征,地表生态具脆弱性; 岩溶关键带碳循环过程包括岩溶碳循环和生态碳循环两部分,碳汇则由植物碳汇、土壤碳汇和岩溶碳汇组成,初步估算其碳汇通量为64.36 t/(km²·a)。

Characteristics of structure and material cycling of the karst critical zone in Southwest China

The goal of the karst critical zone research is to reveal the dynamic balance and evolution mechanism of the karst ecosystem, which can provide the sustainable management strategies of resources environment service for economic society. The research can indicate how to strengthen the flexibility of the karst critical zone under the reasonable Human activities, and provide the effective means to repair the damaged parts. Carbonate, as the soluble rock, gives the karst critical zone some particularities in structure and lithosphere-biosphere interaction of material cycling processes. Taking the karst area of Southwest China as an example, through summarizing the research results of many scholars, the authors revealed the regional difference of the karst critical zone development thickness, that explains why the thickness is several meters in Guilin karst area and one thousand meters in Wulong karst area of Chongqing. The vertical material cycling processes of the karst critical zone regard soil-surface karst zone as the central link, but it horizontally shows the island-like embedded distribution. The surface ecology is fragile. The carbon cycling processes of the karst critical zone include karst carbon cycling and ecology carbon cycling. The carbon sinks are composed of plant carbon sinks, soil carbon sinks and karst carbon sinks, and the total flux of these carbon sinks is 64.36 t/(km²·a) by the preliminary estimation.