Assessment of the ecosystem health of the national Huihe wetland reserve
辉河湿地国家自然保护区生态系统健康评价

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.