关键词: 生态系统服务流, 供应和需求, 区域生态一体化, 时空动态

Abstract:

Rapid urbanization often leads to dynamic adjustments in the supply-demand relationships of ecosystem services (ESs) due to population mobility and changes in land use. Ecosystem service flows (ESFs) provide a critical mechanism for linking ESs supply and demand, offering insights into their interactions, and enabling more accurate evaluations of their spatiotemporal dynamics. However, significant gaps remain in the existing research regarding the quantitative characterization of ES flow volumes, directions, and pathways. Current studies also lack the ability to visualize multiple ESFs in a realistic manner, which poses challenges for integrating ESFs into dynamic regional ecosystem service supply-demand (ESSD) assessments. In addition, the characteristics of ESSD mismatches vary significantly over long temporal scales, preventing the development of sustainable and differentiated management strategies tailored to regional ecological integration goals. To address these limitations, this study adopts an ecological integration framework and employs multiple methodological tools, including the ecosystem gross product (GEP), minimum cumulative resistance (MCR) model, and Gaussian distance decay function-weighted origin-destination (OD) cost path matrix. Building on the construction of a comprehensive value flow model, this study systematically analyzed the ESSD matching characteristics in the Yellow River floodplain (YRFP) over a 30-year period. This approach represents the first attempt to evaluate the dynamics of ESFs and ESSD before and after long-term flow adjustments. This study introduces a novel quantitative framework focused on the ESFs to identify long-term supply-demand conflicts, providing differentiated management strategies tailored to regions with varying levels of conflict. These findings hold significant practical value in advancing sustainable and scientifically informed ecosystem management. Key findings revealed that prior to flow adjustments, the spatial distribution of supply and demand areas in the Yellow River floodplain (YRFP) remained relatively stable, with supply areas consistently approximately twice the size of demand areas. Deficit areas were primarily located in the central districts of 13 cities marked by intensive human intervention, whereas surplus areas encircled these central demand zones. From 1990 to 2020, the intensity of supply surpluses diminished, whereas the intensity of deficits exhibited a decline followed by an increase, with 2000 emerging as the period with the optimal supply-demand balance. These findings underscore the temporal variability of ESSD dynamics and emphasize the critical importance of long-term monitoring and management. The analysis of ES value flows indicated omnidirectional movement across the YRFP, with flow routes varying annually, and service-specific transmission paths contributing to distinct flow characteristics. These comprehensive value routes displayed attributes similar to those of rivers, transportation networks, and atmospheric dynamics, thereby reflecting the diverse mechanisms underlying the ESF dynamics. From 1990 to 2020, the regions with the highest outflows included Dingyuan County (0.45 billion CNY), Huoqiu County (1.32 billion CNY in 2000), Shou County (2.96 billion CNY in 2010), and Huoqiu County again (4.22 billion CNY in 2020). Conversely, the regions with the largest inflows in 1990 and 2000 were the Qingjiangpu District, with inflows of CNY 1.2769 billion and CNY 3.2480 billion, respectively, primarily originating from Hongze County (CNY 0.2992 billion and CNY 0.6771 billion, respectively). In 2010 and 2020, the largest inflows were observed in the Yingzhou District, with values of 5.1882 billion CNY and 7.3291 billion CNY, respectively, mainly sourced from Funan County (0.9678 billion CNY and 1.2534 billion CNY). Post-flow adjustments showed positive impacts on the supply-demand matching status of demand regions, with numerous supply areas transitioning from surplus states to balanced conditions. Notable exceptions were observed in 12 counties within Zhengzhou, Kaifeng, and Yangzhou, where supply-demand ratios and intensities reversed between 1990 and 2020. These reversals underscore the necessity for long-term investigations of ESSD dynamics and development of strategies to mitigate imbalances. Spatially, the distribution of supply-demand conflicts over the 30-year study period exhibited a distinct pattern, with high conflict intensity in the “northwest and southeast” regions and lower conflict intensity in the central regions. High-conflict areas were concentrated in nine counties within Zhengzhou and Yangzhou, whereas moderately high-conflict areas were distributed across 14 counties in Xuchang, Kaifeng, Huainan, Chuzhou, Yangzhou, and Huai’an. Lower conflict areas were primarily located in three counties in Zhengzhou, whereas low-conflict regions encompassed 86 counties surrounding the urban centers. Factors such as population density, urbanization levels, and regional development pressures were identified as key drivers of heightened the ESSD conflicts. This study identified several areas for future research to enhance the precision and applicability of the ESSD assessments. First, the spatial spillover effects of ESFs should be examined thoroughly to understand their influence on regional ESSD dynamics. Second, efforts should focus on refining the resistance surface construction for various service-specific transmission paths to improve the accuracy of the ESF modeling. Third, it is crucial to quantify the contributions of individual ES types to comprehensive value assessments, enabling more nuanced evaluations of their role in regional ESSD. Addressing these research priorities will significantly improve the precision of ESF-based dynamic ESSD-matching outcomes and facilitate the development of scientifically grounded and sustainable management strategies in conflict-prone regions. This study proposes a novel approach for investigating ESSD matching characteristics by constructing an integrated value flow model. It addresses a critical research gap by incorporating the long-term dynamic features of ESSD and ESFs to identify regions with persistent supply-demand conflicts. This study suggests that alleviating long-term conflicts should focus on ES functionality combined with supply demand flow characteristics. In addition, it emphasizes the need for ecological compensation mechanisms based on ecosystem service value transfers to manage conflict-prone areas. This framework provides practical solutions and scientific guidance for ESs management in the context of rapid urbanization and dynamic regional evolution.

Key words: ecosystem service flows, supply-demand, regional ecological integration, spatio-temporal dynamics