内蒙古自治区湿地生态系统特征及驱动力分析

目的]分析维持湿地生态系统平衡的主要影响因子,对提高湿地生态环境管理具有重要意义。方法]利用内蒙古湿地资源调查数据,采用层次分析法,对内蒙古自治区内湿地环境因子进行了分级与综合评价。将所调查的影响因子划分为自然指标和社会环境指标两类,并参考国内外评价指标标准,从景观指标、生物多样性指标、环境指标、人为干扰指标和威胁指标等5个方面,构建湿地生态系统特征评价体系;筛选出天然湿地率、湿地斑块密度、湿地利用状况、人口密度、人类活动强度及农药化肥施用强度等18个指标进行标准化分级,并确定指标权重。根据各指标对湿地生态系统的影响程度,分析湿地生态系统特征的主要驱动因素。结果]对湿地生态系统特征具有显著影响的主要因素依次为:水质级别、单位面积物种多度、植被覆盖度、威胁程度、富营养化程度及威胁因子数量,且景观指标中的景观多样性、湿地斑块密度及景观均匀度对湿地生态格局影响较小。结论]内蒙古自治区内湿地生态系统受社会环境因素影响较大,应加强湿地生态保护。

THE CHARACTERISTICS OF WETLAND ECO-SYSTEM AND THE DRIVING FORCE IN INNER MONGOLIA AUTONOMOUS REGION

It is important to improve the ecological environment management of wetland which could maintain the eco system balance. Whereas the comprehensively assessment of the ecological status of the wetland was not only the basis of wetland protection and rational utilization, but also the guide for improving ecosystem management of wetlands. The methods of analytic hierarchy process (AHP) was used to assess and grade the ecological status the key wetlands in Inner Mongolia Autonomous Region (Inner Mongolia hereafter), based on the data obtained on the wetland resources survey, aiming to satisfy the comprehensive assessment of the environmental factors of the wetlands. The impact factors were divided into national indexes and social environmental indicators, including landscape metrics, biodiversity indicators, environmental indexes, man made interference indexes and threat criteria. With a reference of foreign and domestic evaluation criteria, there were 18 indicators such as natural wetland rate, patch density, wetland utilization status, population density, human activity intensity and use strength of pesticides and chemical fertilizer, which were classified into different grades according to their influences on the ecosystem health of the wetlands. AHP was used to determine the weights of the indicators. The results showed that the indicators of water grades, species abundance in the unit area, vegetation coverage, the threat level, eutrophication degree and number of threat factors, could significantly influence the characteristics of wetlands eco system, respectively. Otherwise, the indicators of landscape diversity, wetland patch density and landscape evenness index of the landscape metrics, should be less significant contribution to the wetland landscape. However, some wetlands were unsatisfactory in terms of their ecological status. It concluded that there was a significant effect of the social environments especially the human influence to the ecosystem balance of the wetland. The constructed indicator system was reasonable. Moreover, the measures of protecting the wetland ecology should be given and the wetland protection should be strengthened in Inner Mongolia.