生态建设背景下三江源自然保护区生态系统服务价值变化

摘要

青海三江源是我国淡水资源的重要补给地,也是全国生态保护和建设工程的重点实施区域,对其开展生态恢复过程的生态系统服务价值变化研究,有利于揭示生态保护和建设工程的实施效果.在构建三江源生态系统服务价值评估指标体系的基础上,选择生态工程前后两个时间段(2000年和2008年),采用物质量和价值量相结合的方法对三江源自然保护区生态系统服务价值进行了评估和对比分析,结果表明:2000-2008年保护区生态系统服务总价值呈现明显的增长趋势,8 a间一共增加1.68×1010元.保护区草地生态系统的整体质量状况大幅度提升,生态系统服务价值增加48.69％,是由生态建设和气候因子变化共同作用的结果；森林生态系统服务价值增加12.71％,主要跟森林区域水热条件的改善有关；水体与湿地生态系统服务价值在8 a间减少56.08％,关键是由区域气温升高和降水量减少所致,而非人为因素的影响；2000-2008年间,保护区人口数量增加了26.08％,较高的人口增长压力促使大量的草地被开垦为农田,导致农田面积增加392.52％,从而引起农田生态系统服务价值大幅波动.%Climate change and irrational human activities could lead to the occurrence of ecological degradation,which consequently cause declination of ecosystem services ;however,restoration actions could be generally effective in increasing the provision of ecosystem services.In the context of this study,we attempted to perform an analysis of the changes in ecosystem service values in response to ecological construction in the Three-River Headwaters Nature Reserve (TRHNR) of China.We used remote sensing and geographic information system (GIS) technology,as well as ecological economics methods,to evaluate the ecosystem services contributed by the TRHNR in the year 2000 and 2008.The results showed that the ecosystem service value (ESV) in the TRHNR increased 16.80 billion yuan(RMB) during the study period.Among the six ecosystem categories,the overall quality of grassland had improved significantly with the double effect of ecological construction and climate variation,and the ESV of grassland had increased 48.69％.There was a slight increase of 12.71％ in ESV of forest which was mainly related to the improvement of hydrothermal conditions in the forest area.The ESV generated by wetland decreased 56.08％ due to the regional temperature rise and precipitation reduction.From 2000 to 2008,the population of the study area increased 26.08％,which induced anintense transformation between farmland and grassland,further caused a high growth rate in ESV of farmland.The results indicated the impacts of different drivers on the ESV of each ecosystem,and revealed that the Project of Ecological Protection and Construction in the study area played a crucial role in ecosystem service production.