辉河湿地国家自然保护区生态系统健康评价

在RS和GIS技术的支持下,以1975和2006年两期遥感影像为信息源,从生态系统空间范围和服务功能价值变化的角度对呼伦贝尔辉河草原湿地国家级自然保护区的生态系统健康状况进行了分析.结果表明,1975～2006年间辉河湿地自然保护区的草原和湖泊面积分别减少了7346和2731hm2,湿地和干涸湖面积分别增加了6877和2953 hm2.从自然保护区的核心——湿地生态系统的斑块格局变化来看,1975～2006年间斑块密度增加了74.48个.hm-2,斑块连通度在100～300m的阈限值范围内呈减少的趋势,平均减少0.069±0.038.基于生态系统服务价值的评价结果表明,1975～2006年间辉河湿地国家自然保护区生态系统达到健康水平以上的区域面积为323215 hm2,占保护区面积的93.31%,生态系统较差和恶劣区的面积为23177 hm2,占总面积的6.69%.研究区的总生态价值盈余为8.8×107元,其盈余主要来源于草原向湿地的转化、水体向湿地的转化及干涸湖向草原的转化.

Assessment of the ecosystem health of the national Huihe wetland reserve

In terms of spatial features and service values, and based on MSS images in 1975 and 2006, we examined ecosystem health status of the Huihe National Wetland Reserve in Hulunbeier grassland by means of RS and GIS techniques. Results shows that there was a significant change in the areas of grassland, lake, wetland, and dried-up lake during 1975 to 2006 period, with an area changed by -7346 hm2, -2731 hm2, 6877 hm2 and 2953 hm2, respectively. Wetland, as an important component of the Reserve, varied most obviously in terms of patch scale during this period. Patch density increased by 74.48•km-2 and patch connectivity index decreased by a mean value of 0.069 (±0.038) in the threshold range of 100 to 300 m. From the view point of ecosystem health assessment, over 93.3% of the total area (323215 hm2) is health, and remaining 6.7% of the total area (23177 hm2) has become not health or worse since 1975 in terms of health status. Ecosystem service value of the Reserve has increased by 8.8×107 RMB during this period, mainly due to the conversion of grassland and lake to wetland, and dried-up lake to grassland.