石羊河流域生态系统服务时空变化及其多尺度影响因素研究

Spatial and temporal variability of ecosystem services in the Shiyang River Basinand its multi-scale influencing factors

对生态系统服务时空变化的影响因素开展多尺度定量分析,是揭示生态系统服务演化机理和推进区域可持续发展的重要突破口。既有研究侧重于从行政或流域的等级确定研究尺度大小,缺乏科学合理的尺度划分方法。论文以石羊河流域为研究区,评估了食物供给、碳固存、产水量和防风固沙4种生态系统服务的时空变化特征,并应用小波分析和参数最优地理探测器模型确定了生态系统服务时空变化影响因素研究的最佳尺度及不同尺度下的主要影响因子。结果表明:①2000—2020年石羊河流域食物供给、碳固存、产水量和防风固沙4种生态系统服务均呈上升趋势。食物供给服务增幅最大,增幅为138.3%,碳固存、产水量和防风固沙服务增幅分别为0.97%、7.6%和9.5%。②根据4种生态系统服务的小波方差主周期,2000—2020年和2010—2020年分别构建了6个、2000—2010年构建了7个影响因素研究的特征尺度。③随着尺度增大,影响因子对生态系统服务时空变化的作用程度逐渐增强,且不同尺度的主要影响因子存在明显差异。食物供给和碳固存服务在小尺度上主要受人文因子影响,大尺度上受自然因子影响;产水量服务在不同尺度上始终受自然因子影响;防风固沙服务随尺度增大人文因子影响程度显著增强。④尺度增大过程中不同交互因子q值的增加趋势不同,其中碳固存和防风固沙服务中人文因子间的交互作用显著增强。论文通过小波分析改进了传统的多尺度序列构建方法,可为优化区域生态系统结构及制定多级生态系统管理决策提供参考。

A multi-scale quantitative analysis of the factors that influence the spatial and temporal changes in ecosystem services is an important breakthrough in revealing the mechanisms of ecosystem service evolution and promoting sustainable regional development.Existing studies focus on determining the scale of research from the administrative division or watershed level,and lack scientific and sound scale division methods.Taking the Shiyang River Basin as the study area,this study evaluated the spatiotemporal variation characteristics of four ecosystem services—food supply,carbon sequestration,water production,and wind and sand control.Wavelet analysis and the optimal parameters-based geographical detector model were used to determine the optimal scale and the main influencing factors at different scales for studying the spatiotemporal changes of ecosystem services.The results show that:1)The four ecosystem services(food supply,carbon sequestration,water production,and wind and sand control)in the basin all showed an increasing trend from 2000 to 2020.Food supply services increased the most,by 138.3%,while carbon sequestration,water production,and wind and sand control services increased by 0.97%,7.6%,and 9.5%respectively.2)According to the wavelet square difference main cycle of the four ecosystem services,six characteristic scales of influencing factors were constructed from 2000 to 2020 and from 2010 to 2020,and seven from 2000 to 2010,respectively.3)With the increase of scale,the effect of the influencing factors on the temporal and spatial changes of ecosystem services gradually increased,and the main influencing factors at different scales were significantly different.Food supply and carbon sequestration services were mainly affected by human factors on a small scale and natural factors on a large scale.Water production service was always affected by natural factors at different scales.With the increase of scale,the influence of human factors on the wind and sand control service was significantly enhanced.4)The increasing trend of q-values of various interaction factors in the process of increasing scale is different and among these,the interaction between the human factors of carbon sequestration and wind and sand control services is significantly enhanced.This study addressed the inadequacies of the traditional multi-scale sequence construction method through wavelet analysis,which can provide a reference for optimizing regional ecosystem structure and making multi-level ecosystem management decisions.