基于服务流的长三角生态系统服务供需时空格局演变OACHSSCD

An in-depth analysis of the spatio-temporal patterns of ecosystem service supply,demand,and their relationships,coupled with a systematic exploration of how ecosystem service flows influence these supply-demand patterns,is crucial for achieving effective ecosystem management and formulating scientifically sound ecological conservation plans.Current research predominantly focuses on static assessments of the quantities of supply-demand and the spatial relationships of ecosystem services,while often neglecting their spatial mobility.This leads to an overemphasis on local supply-demand balances and a failure to account for cross-regional ecological linkages.Taking the Yangtze River Delta region as the research object,this study integrated multi-source remote sensing data and statistical materials,and employed the InVEST model to conduct a scientific assessment of two key ecosystem services:food provision and water yield.It systematically analyzed the spatio-temporal evolution patterns of supply and demand across six characteristic years from 2000 to 2022.Based on the quantitative assessment results,the study further explored the evolution of supply-demand balance and matching prior to ecosystem services flows.By introducing a spatial analysis framework for ecosystem service flows,it tracked the spatial flow trajectories of food production and water yield services,and dynamically simulated the evolution of supply-demand balance patterns following cross-regional transmission.The research results showed that:(1)From 2000 to 2022,significant spatio-temporal differentiation occurred in the supply-demand patterns of ecosystem services in the Yangtze River Delta region.The food service showed a trend characterized by"increase in the north and decrease in the south"and"surplus in the north and deficit in the south",with deficit areas expanding alongside urbanization.Influenced by climate and urbanization,the water yield service demonstrated a trend characterized by a first rise followed by a decline in supply and a fluctuating upward trend in demand.A clear north-south differentiation was observed:river basins in the south maintained a continuous surplus,while the Huaihe River basin in the north experienced fluctuating deficits.(2)The"north-to-south grain transportation"pattern in food service flows was continuously reinforced,with the circulation scale showing phased leaps.The north-south net output increased year by year,and cross-regional service flows effectively alleviated local shortages.(3)The spatial pattern of water yield service flows was rigidly constrained by natural geographical conditions,forming"high-value corridors"along the main streams of the Yangtze River,Qiantang River,and Huaihe River.The cumulative volume of flowing water generally increased from 2000 to 2020 but dropped sharply in 2022 due to a dry year,highlighting the sensitivity of water resource supply to climate fluctuations.Moreover,it failed to effectively alleviate local shortages at the county scale.