石羊河流域自然植被对生态系统服务的约束效应

石羊河流域生态环境退化,生态屏障功能减弱,提高该地区生态系统的服务功能具有重要意义。植被的生长状况是影响生态系统服务供给的重要因素,定量的探讨分析植被与生态系统服务之间的关系十分必要。以石羊河流域为研究区,采用约束线法,分析了植被对产水量、土壤保持及固碳3个生态系统服务的约束效应;同时,计算了2015年这3个生态系统服务潜力的空间分布及石羊河流域综合潜力分布格局。结果表明:(1)植被覆盖度与产水量、土壤保持之间的约束线呈开口向下抛物线型,即随着植被覆盖度的增加,约束效应逐渐减小,后逐渐增大;与固碳服务呈正凸型,即:植被覆盖度能有效的约束固碳,且成比例增加约束效应;(2)植被覆盖度对产水量、土壤保持及固碳服务的约束效应存在时空异质性;(3)石羊河流域三种服务的提升潜力均呈西南高东北低、高服务值与高潜力值并存的分布特征,其中东大河、西大河、西营河及古浪河是流域生态服务的主要供给者和服务潜力提升的主要贡献者。

Study on the constraint effect of natural vegetation on ecosystem services in the Shiyang River Basin

The ecological environment of the Shiyang River Basin is degraded, and the function of the ecological barrier is weakened. Therefore, it is of great significance to improve the ecosystem services and functions in this area. The growth of vegetation is an important factor that affects the supply of ecosystem services. It is necessary to quantitatively analyze the relationship between vegetation and ecosystem services. In this paper, the constraints of vegetation on water yield, soil conservation, and carbon sequestration in the Shiyang River Basin are analyzed by the constraint line method. At the same time, the spatial distribution of the three ecosystem service potentials in 2015 and the distribution pattern of the comprehensive potentials in the Shiyang River Basin were calculated. The results show that: (1) the constraint line between vegetation coverage and water production and soil conservation is a downward open parabola. That is, with an increase of vegetation coverage, the restraint effect gradually decreases and then gradually increases. The carbon service is positively convex. (2) Restrictive effects of vegetation coverage on water yield, soil conservation and carbon sequestration is temporally and spatially heterogeneous. (3) The characteristic of upgrading potentials of the three services is that the value of southwest is higher than of northeast with Coexistence of High Service Value and High Potential Value in the Shiyang River Basin. The Dongda, Xida, Xiying, and Gulang Rivers are the main contributors to the improvement of ecological services and service potential.