内蒙古草原生态系统健康评价体系构建——基于植被型、植被亚型、群系三个等级

Construction of Grassland Ecosystem Health Evaluation System in Inner Mongolia: Based on the Formation, Vegetation Subtype and Vegetation Type

合理进行草地生态系统健康评估可以从宏观尺度上准确了解草地生态系统的时空配置分布,是实现草地科学管理和合理利用的基础。本研究基于内蒙古草原194个样方数据,采用CVOR综合指数方法,选定22个指标因子建立内蒙古草原生态系统健康评价指标体系,并通过熵值法确定各指标和准则层权重值,分别从植被型、植被亚型、群系三个等级对草地生态系统健康状态进行评价。结果表明:三个等级下,准则层中基况和活力两个指标权重均较大,恢复力权重普遍较低。三个等级下,基况准则层中全碳、全磷指标权重普遍较高;组织力准则层中,物种丰富度、功能丰富度、系统发育丰富度三个指标权重最重要。在植被型等级下,草地生态系统状况以警戒和不健康为主,健康所占比例极小;在植被亚型等级下,草地生态系统状况以不健康为主,只有荒漠草原出现警戒状态;在群系等级下,各草地生态系统健康状况均以健康为主。植被亚型是最适合开展草原生态系统健康评估的等级。本研究可为合理开展内蒙古草地生态系统健康评价提供科学依据,并为进一步进行草地资源合理利用提供科学指导。

Grassland ecosystem health assessment could help us understand the spatial and temporal distribution of grassland ecosystem accurately from the macro scale,which is the basis for realizing the scientific management and rational utilization of grassland.In this study,based on 194 sites of Inner Mongolia grassland,22 indicators were selected to evaluate the health condition of grassland ecosystem in Inner Mongolia by adopting the CVOR method.Meanwhile,the weight values of each indicator and criterion layer were determined by the entropy method.Grassland ecosystem health was evaluated at three levels,vegetation type level(Inner Mongolia grassland),vegetation subtype level(meadow steppe,typical steppe,desert steppe),and formation(Stipa baykal steppe,Leymus chinensis steppe,S.grandis steppe,S.kryloi steppe,L.chinensis steppe,S.breviflora steppe,S.grandis steppe).The results showed that the weights of condition and vitality in the criterion layer were prominent,while the weight of resilience was generally low.The weights of total carbon and total phosphorus were generally higher in the condition criterion layer.In the organizational criteria layer,species richness,functional richness and phylogenetic richness were the most critical indicators.For the vegetation type,the status of the grassland ecosystem was mainly alert and unhealthy,and the proportion of health was tiny.For the vegetation subtypes,grassland ecosystem condition was given priority to unhealthy,and only desert grassland appears alert condition.For the formation,the health status of each grassland ecosystem was mainly health.Therefore,vegetation subtypes were the most suitable grade for developing grassland ecosystem health.This study could provide the scientific basis for the rational evaluation of grassland ecosystem health in Inner Mongolia and provide scientific guidance for the further rational utilization of grassland resources.