武夷山小流域生态系统服务(簇)权衡/协同及对地形起伏度的响应

地形起伏度(RDLS)通过影响生态系统的格局、过程和功能而作用于生态系统服务，揭示二者间的作用关系对提升生态系统服务认知具有重要意义。综合运用地形起伏度模型、InVEST模型、K-mean聚类分析、生态系统服务变化指数(ESCI)及权衡协同度指数(ESTD)等方法，探究2009—2016年武夷山国家公园武夷山九曲溪流域主要生态系统服务、生态系统服务簇及其权衡/协同关系对地形起伏度的响应规律。结果表明：(1)2009—2016年生物多样性维持、固碳、水源涵养和水质净化服务及其增益面积均随着RDLS等级的升高而增加。(2)生态脆弱型服务簇聚集在RDLS较低地方，生态调节型服务簇则聚集在RDLS较高区域，而生态保育型服务簇无明显分布规律。2009—2016年，RDLS较低和较高区域分别有19%、18%的生态保育型服务簇转变为生态脆弱型服务簇和生态调节型服务簇。(3)生态系统服务权衡/协同关系对RDLS的响应模式有两种模式，即以二级或四级RDLS为峰值的倒U型曲线(固碳与生物多样性维持的权衡关系，固碳与水源涵养的协同关系)和以二级、四级RDLS为拐点的N型曲线(水质净化与固碳、水源涵养的协同关...

Trade-offs and synergies among ecosystem service Bundles in response to relief degree of land surface in a small watershed of Mount Wuyi

The Relief Degree of Land Surface (RDLS) represents the undulation of a region''s terrain and is determined by the elevation change relative to the flat land. RDLS is a macroscopic indicator of topographic features that are closely linked to local climate, vegetation, biodiversity, land use/cover, and human activities. These factors significantly influence ecosystem patterns, processes, and functions, which are fundamental to the provision of ecosystem services. Therefore, revealing RDLS''s effects has great implications for improving ecosystem services. Previous studies have examined the distribution pattern, value, and temporal and spatial evolution of ecosystem services based on regional topographic gradients. However, the response process of ecosystem services and their trade-off/synergistic relationship with RDLS in the watershed remains unclear. To address this gap, we conducted a study focused on the Jiuquxi watershed, which is the core watershed in Wuyishan National Park. And we explored the response of key ecosystem services, ecosystem service bundles and their trade-off/synergistic relationships to the RDLS in Jiuquxi watershed from 2009 to 2016, using relief degree of land surface model, InVEST model, K-mean clustering analysis, ecological services change index (ESCI), and ecosystem services trade-off degree (ESTD). The results showed that (1) the ecosystem services including biodiversity, carbon sequestration, water yield and water purification increased with the increase of RDLS during 2009-2016, as did their gain area. (2) In the Jiuquxi watershed, ecosystem services can be categorized into three types of bundles:eco-fragile bundles, where all four services are low; eco-regulating bundles, where all four services are high with carbon sequestration being dominant; and eco-conservation bundles, where all four services are high with biodiversity being dominant. The eco-fragile bundles clustered in the regions with low RDLS value and eco-regulating bundles in the area with high RDLS value. While the eco-conservation bundles had no typically spatial pattern for ESCI. From 2009 to 2016, 19% of the areas in eco-conservation bundles in low RDLS region were transformed into eco-fragile bundles and eco-conservation bundles, and 18% in high RDLS region. (3) The pattern of ecosystem service trade-offs/synergies in response to RDLS was identified:an inverted U-shape curve with secondary or quaternary RDLS at its peak (e.g., the trade-off between carbon sequestration and biodiversity, and the synergistic between carbon sequestration and water yield) and the N-type curve with secondary and quaternary RDLS as the inflection point (e.g., synergistic between water purification, carbon sequestration and water yield, and the trade-off between water purification and biodiversity).