基于生态系统服务供需的农牧交错带流域生态修复分区—以桑干河上游为例

基于农牧交错带流域生态本底和社会经济特征开展生态修复分区研究，有助于维护农牧交错带生态安全和社会经济可持续发展。以地处农牧交错带的桑干河上游为例，选取土地利用、气象观测、统计年鉴等多源数据，基于InVEST模型和ArcGIS空间分析模块探讨2020年桑干河上游碳固持、食物供给、产水和土壤保持这4项生态系统服务供需空间分布格局，并通过象限匹配法和耦合协调度模型进行生态修复分区研究。结果表明：2020年桑干河上游4项典型生态系统服务供给的空间分布与流域地形地貌基本保持一致，形成一个环绕桑干河主干道的半闭环式的高值带，需求的高值区则与人口密集区基本吻合。桑干河上游生态系统服务供需匹配类型以高供给-高需求和高供给-低需求的匹配类型为主，供需耦合协调度平均值为0.23，处于轻度失调状态，生态系统服务供需错配现状突出。根据桑干河上游生态系统服务供需匹配和耦合协调关系及社会经济特征，将桑干河上游划分为5个生态修复区，即神头泉域生态修复区、北部古长城沿线生态屏障带、大同盆地防风固沙区、内长城沿线水源涵养和生物多样性保护区、桑干河水生态修复与生态多样性保护带，并通过搭配组合“辅助再生、自然恢复、生态重建、保护保育”等生态修复措施，提升各分区以固碳保持、耕地保护、水源涵养、水土保持为主的生态功能。

Ecological restoration zoning in farming-grazing transitional zone based on the supply and demand of the ecosystem services: a case study of the upper reaches of the Sanggan River

The research on ecological restoration zoning, based on the ecological background and socio-economic characteristics of the farming-grazing transitional zone, will contribute to its ecological security and sustainable socio-economic development. The upper reaches of the Sanggan River, located in the farming-grazing transitional zone, were selected as the research area to identify the ecosystem services, including carbon sequestration, food supply, water production and soil conservation. The multi-source data about land use, meteorological observation and statistical yearbooks, etc., were employed in InVEST model and ArcGIS spatial analysis module, to explore the spatial distribution of the supply and demand of the ecosystem services in the upper reaches of the Sanggan River in 2020. Moreover, Quadrant matching method and coupling and coordination model were adopted to conduct research of the zoning of ecological restoration. The results showed that: In 2020, the spatial distribution of the supply of the four ecosystem services in this area was almost consistent with its topography, forming a semi-closed loop of high value around the backbone artery of the Sanggan River. The high demand for ecosystem services was located where densely populated areas occurred. Matching types of the supply and demand of ecosystem services in the river basin were "high supply -high demand" and "high supply-low demand". The average value of coupling and coordination degree between the supply and demand was 0.23, which was in a state of mild imbalance and indicated a mismatch between the supply and demand of ecosystem services. Based on the matching types and coupling and coordination degree of the supply-demand of the ecosystem services as well as the socio-economic characteristics in the upper reaches of the Sanggan River, the tributary was divided into Shentou Springs ecological restoration area, the ecological barrier zone along the northern ancient Great Wall, the sand-fixation belt in Datong Basin, the water conservation and biodiversity protection area along the inner regions of the Great Wall, and the ecological restoration and biodiversity protection area of the Sanggan River. Coupled with the ecological restoration measures such as assisted regeneration, natural restoration, ecological reconstruction, and protection and conservation, the ecological functions of each zone, mainly focusing on carbon sequestration and conservation, cultivated land protection, water conservation, and water and soil conservation, would be greatly promoted.