黄土高原生态系统服务供需关系的时空变化

明晰生态系统服务供需匹配关系,对实现区域生态安全与社会经济可持续发展具有重要推动作用。本文以黄土高原为案例区,应用InVEST模型、ArcGIS、GeoDA等分析工具,分析黄土高原粮食供应、水源涵养、碳固存、土壤保持等服务的供需量及其匹配关系的时空变化,旨在为黄土高原国土空间格局优化提供决策依据。结果表明：1990—2018年,① 黄土高原除水源涵养服务供给量外,其他生态系统服务供需量均呈上升趋势,且各生态系统服务供给量及土壤保持服务需求量均呈“东南高、西北低”的分布特征,而粮食供应、水源涵养、碳固存服务需求量呈“四周高、中间低”的分布特征;② 各类生态系统服务供需比均呈下降趋势。空间分布上,粮食供应、碳固存服务在黄土高原四周人口密集区供不应求,而其他区域供大于求;水源涵养服务在该区西北部供不应求,但东南部供大于求;土壤保持服务供不应求区集中于鄂尔多斯高原及海北州北部;③ 各类生态系统服务供需均以低低空间匹配为主;④ 粮食供应、水源涵养、碳固存服务供需比的空间分布均以高高集聚为主,而土壤保持服务以低低集聚和高高集聚为主。除土壤保持服务供需比的空间集聚性有所增强外,其他生态系统服务均呈减弱趋势。

Spatiotemporal changes of supply and demand relationships of ecosystem services in the Loess Plateau

Clarifying the match of the supply and demand of ecosystem services is crucial for promoting regional ecological security and sustainable socio-economic development. This paper takes the Loess Plateau as an example, and applies InVEST model, ArcGIS, GeoDA to analyze the spatiotemporal changes of the supply, demand and their match, which involves crop supply, water conservation, carbon sequestration and soil conservation, aiming to provide a decision-making basis for optimizing the territorial spatial pattern in the Loess Plateau. The results show that: (1) except the supply of water conservation, the supply and demands in other fields are on the rise. The supply of ecosystem services and the demand of soil conservation present the distribution pattern of "high in the southeast, but low in the northwest", while the demands of crop supply, water conservation and carbon sequestration have the distribution pattern of "high in the surroundings, while low in the middle". (2) The supply-demand ratio of various ecosystem services shows a general downward trend. In terms of spatial distribution, the demands of crop supply and carbon sequestration outstrips the supply in densely populated areas, and the supply exceeds the demands in other areas; in the northwest of the study area, the demand of water conservation outstrips the supply, while the supply exceeds the demand in the southeast; the soil conservation service in short supply areas are mainly found in the Ordos Plateau and Haibei prefecture. (3) The supply and demands of various ecosystem services are mainly low-low spatial matching. (4) The spatial distribution of the supply-demand ratio of crop supply, water conservation and carbon sequestration is mainly high-high agglomeration, while the soil conservation is mainly low-low and high-high agglomeration. Except for the enhancement of the spatial agglomeration of the supply-demand ratio of soil conservation service, the others tend to weaken.