岩溶生态系统脆弱性研究

生态系统的脆弱性评价对于生态系统管理具有重要作用。在分析岩溶生态系统脆弱性特 征和影响因素的基础上，构建了针对岩溶自然系统的脆弱性评价指标体系， 涵盖了岩溶生态系统 的结构脆弱性、生态过程脆弱性、生态功能脆弱性和人为胁迫脆弱性4 个方面，评价指标分别是 结构稳定性、多样性生境、能量利用和积累、直接使用价值、石漠化程度和速率等。以不同类型的 原生岩溶生态系统的生态基准值作为比较基础， 评价系统将现有的退化岩溶生态系统的脆弱性 划分为轻微脆弱、中度脆弱、重度脆弱以及系统崩溃4 级。

A Conceptual Analysis of Kar st Ecosystem Fr agility

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.