黄土高原土壤保持服务供需平衡及其驱动因素

土壤保持服务是黄土高原重要的生态系统调节服务,明确土壤保持服务供需空间格局及驱动因素,对于实现黄土高原生态系统管理和资源有效配置具有重要意义。采用修正通用土壤流失方程(RUSLE)量化了2000—2018年黄土高原土壤保持服务供给量和需求量,并分析其时空演变及供需匹配特征,基于地理加权回归(GWR)模型探究不同因子对土壤保持供需平衡影响的空间异质性。结果表明：(1)2000—2018年,黄土高原土壤保持服务供给量、需求量以及供需比均呈现波动增加的趋势,增幅分别为57.13%、11.9%、150%。供给量和需求量均呈现“东南高、西北低”的空间分布格局,供需比高值位于黄土高原东北部和西南部,低值位于西北部。(2)黄土高原土壤保持服务供需以低低型空间匹配为主,主要分布在黄土高原的西北部和东南部地区。(3)黄土高原土壤保持供需主要受到坡度、NDVI、降水、DEM以及人口密度的影响。其中,坡度、NDVI、降水和DEM表现出明显的正向促进作用;人口密度既有正向促进作用又有负面抑制作用,但促进作用强于抑制作用。该研究对优化调控黄土高原生态建设以及促进区域可持续发展具有一定的借鉴意义。

Analysis on supply and demand balance of soil conservation service and its driving factors on the Loess Plateau

Soil conservation service is an important ecosystem regulation service on the Loess Plateau. It is of great significance to clarify the spatial pattern and driving factors of soil conservation service supply and demand for the realization of ecosystem management and the effective allocation of resources on the Loess Plateau. This paper quantified the supply and demand of soil conservation service on the Loess Plateau from 2000 to 2018 using the revised universal soil loss equation (RUSLE), and analyzed their spatial and temporal evolution and supply-demand matching characteristics, and then explored the spatial heterogeneity of the impacts of different factors on the supply-demand balance of soil conservation service based on the geographically weighted regression (GWR) model. The results showed that (1) from 2000 to 2018, the supply, demand and the supply-demand ratio of soil conservation service on the Loess Plateau showed a fluctuating trend of increase with the growth rate of 57.13%, 11.9% and 150%, respectively. The supply and demand of soil conservation service both showed a distribution pattern of "high in the southeast and low in the northwest". The high values of supply-demand ratio were located in the northwest and southeast of the Loess Plateau, while the low values were located in the northwest. (2) The supply and demand of soil conservation service was mainly low-low spatial matching and was distributed in the northwestern and southeastern areas of the Loess Plateau. (3) The balance of soil conservation service supply and demand was mainly affected by slope, Normalized Difference Vegetation Index (NDVI), precipitation, Digital Elevation Model (DEM) and population density. Among them, slope, NDVI, precipitation and DEM showed obviously positive promotion effects. Population density had both positive and negative effects, but the positive effects were stronger than the negative effects. This study has implications for optimizing the regulation of ecological construction on the Loess Plateau and promoting regional sustainable development.