A Conceptual Analysis of Kar st Ecosystem Fr agility
岩溶生态系统脆弱性研究

Assessing the fragility of ecosystem has an important role to sustainable ecosystem management. Karst environments, unique from other environments, is one kind of typical fragile ecosystem and key eco-region in China. Based on a critical review of current research about karst ecohydrological processes, soil fragility, vegetation characteristics, and the reciprocity of water, soil and plant in karst ecosystem, we developed an indicator system for assessing the fragility of degraded karst ecosystems, which including ecological structure fragility, ecological processes fragility, ecological function fragility and artificial menace fragility of karst ecosystem.. Therefore, the evaluation indicator should explain the change and diversity of ecological structure, ecological process and ecological function. According to this principle, some index such as structure stability, diversity of microhabitat type, energy utility and accumulation, direct use value, the degree and speed of karst rocky desertification was chosen. Furthermore, the fragility of degraded karst ecosystems was divided into four levels by this assessment system as follows: slight fragility, medium fragility, severe fragility and ecosystem collapse compared with the ecological baseline of undisturbed karst nature ecosystem.