锡林河流域天然草地生态系统服务价值评价

Evaluation of grassland ecosystem services in Xilin River basin

锡林河流域天然草地是我国北方重要的生态保护屏障,其关键的地理位置和独特的生境条件使其具有十分重要的生态意义和经济价值。本研究根据草地的产草量和退化程度将锡林河流域天然草地划分成5个等级,利用Costanza的生态系统服务功能评价的基本思路和方法,对锡林河流域天然草地生态系统服务价值进行了评估:首先分别计算每一等级草地单位面积的各项生态系统服务功能的服务价值,然后求和得到该流域草地的总服务价值。结果表明,锡林河流域草地生态系统每年的服务价值为76.154×108元。受各级草场的生产量和放牧强度的综合影响,健康程度不同的各等级天然草地的单位面积生态系统服务功能的价值存在着很大差异,从第1级草地到第5级草地,单位面积服务价值比重从38.1%下降到4.8%。参考国际、国内和锡林浩特当地3种不同的生态系统服务单价,通过计算得出这3种不同空间尺度下锡林河流域天然草场生态系统服务价值分别为:88.199×108,76.154×108和14.236×108元/年,并且各项服务功能在总价值中所占的比例也随空间尺度的不同而不同。以气体调节为例,服务价值的比重分别占3.7%,11.0%和7.9%,这说明生态系统服务功能的价值与空间尺度有关。

Ecosystem service is one of the hotspots of ecology, natural resources science and economics. Grassland ecosystems are the second largest vegetation stratum, smaller only than the forest ecosystem. In China, the grassland ecosystem is the biggest terrestrial ecosystem,and the usable area of grassland resources reaches over 3.9×10^8 hm^2. Therefore, it plays a crucial role in maintaining structures,functions and ecological processes of natural ecosystems. As one ecological protective barrier in North China, the Xilin River basin grassland has a pivotal location and unique habitat condition. Therefore, it is very important to evaluate its ecosystem services. This paper appraises the value of grassland ecosystem services in the Xilin River basin, using the methodology of Constanza. We divided the Xilin River basin natural grassland into 5 grades on the basis of bio- mass and the hierarchical standard of degraded grassland, and then calculated the total economic evaluation of grassland ecosystem services in the Xilin River basin through summing the service value in unit area of grassland of each ecosystem type. Results showed that the total value of the annual grassland ecosystem services was about 76. 154 ×10^8 yuan. For the integrated effects of productivity and grazing density, the contribution ratio of ecosystem services per hectare of different grassland at 5 health levels differed greatly. From the 1st grade to the 5th grade, the contribution ratio was reduced. it reduced to 4.8% for the 5th grade of grassland. in the XiLin River basin were different at three The contribution ratio of the 1st grade reached 38. 1%, but Furthermore, the values of the grassland ecosystem services spatial scales, international, domestic and Xilinhaote local scale. At these three spatial scales, the total values were 88. 199 ×10^8 ,76. 154×10^8 and 14. 236 ×10^8 yuan/a, respectively. For example, for gas regulation, at these three spatial scales, the contribution ratio was 3.7%, 11.0 % and 7.9 % respectively. This finding indicated that the value of ecosystem services was closely related to spatial scale.