退耕还林(草)工程对渭河流域生态系统服务的影响

退耕还林(草)工程作为中国启动的重要生态补偿项目,对维护国家生态安全起着关键作用,系统剖析退耕还林(草)工程对生态系统服务的影响,有助于为健全生态补偿制度提供借鉴。本研究以渭河流域为例,基于土地利用数据、气象数据等资料,在分析退耕还林(草)工程实施以来渭河流域土地利用和生态系统服务时空变化的基础上,运用Invest模型、地理加权回归等方法,探究退耕还林(草)工程对渭河流域水源涵养、土壤保持、碳储量、生境质量等生态系统服务变化的影响。结果表明: 退耕还林(草)工程实施以来,渭河流域林草覆盖率呈波动上升趋势,林草面积增加2704.49 km²。2000—2018年间,渭河流域水源涵养、土壤保持、碳储量、生境质量均呈波动上升趋势,其中,水源涵养和固碳服务增幅较大,生境质量和土壤保持增幅较小。退耕还林(草)工程有效提升了渭河流域的水源涵养、土壤保持、固碳、生境质量等生态系统服务,但对不同地域单元生态系统服务影响强度不同。

Impacts of the returning farmland to forest (grassland)project on ecosystem services in the Weihe River Basin,China

As an important ecological compensation project initiated in China, the returning farmland to forest (grassland) project plays a key role in maintaining national ecological security. Systematical analysis for the impacts of the returning farmland to forest (grassland) project on ecosystem services would provide reference for consummating ecological compensation system. Taking the Weihe River Basin as an example, we analyzed the spatiotemporal changes of land use and ecosystem services since the implementation of the project based on land use data, meteorological data and other information. The InVEST model and geographically weighted regression were used to investigate the impacts of the project on the changes of ecosystem services, such as water conservation, soil conservation, carbon storage, and habitat quality. The results showed that since the implementation of the project, the coverage rate of forest and grassland had been fluctuating upwards, with an increase of 2704.49 km² of forest and grassland area. From 2000 to 2018, in the Weihe River Basin all showed a fluctuating upwards trends. Among those services, water conservation and carbon storage had large increases, while habitat quality and soil conservation had small increases. The project had effectively improved ecosystem services in the Weihe River Basin, but the impacting intensity on ecosystem services varied from one geographical unit to another.