[Supply-demand bundles and ecological function management of urban ecosystem services: Taking central urban area of Qiqihar as an example].

The comprehensive management of multiple ecosystem services is the focus of current research in the field of ecosystem service. The ecological space in the central urban area is scarce, but ecological needs are diverse. How to scientifically use urban land while considering various ecological functions has gradually become an academic hotspot. Taking the central urban area of Qiqihar as an example, we applied the ecosystem service bundle theory to analyze the supply and demand relationship of five ecosystem services in the study area, including flood regulation, air purification, carbon storage and sequestration, biodiversity conservation, and cultural recreation. Based on the supply-demand ratio, we identified the supply-demand bundles of ecosystem services in the study area, completed the division of ecological functional areas, and proposed corresponding spatial control strategies. The results showed that the supply of those five services presented a spatial pattern of low in the city center and south side, while high in the northwest and southeast side, and that the demand for those five services presented a spatial pattern of high in the city center and low around the city. Air purification, biodiversity conservation, and cultural recreation ser-vices were in short supply, with a supply-demand ratio of -0.160, -0.071, and -0.008, respectively. The supply to demand ratios of flood regulation and carbon storage and sequestration services were in excess, with a supply to demand ratio of 0.089 and 0.008, respectively. The spatial imbalance between supply and demand of various services was significant. The research area could be divided into six types of ecosystem service bundles. After comprehensive analysis, the research area would be further divided into four types of zones: urban ecological restoration zone, urban ecological strengthening zone, urban development transition zone, and urban ecological conservation zone. We proposed targeted functional optimization strategies based on the spatial relationship, ecological background characteristics, and supply and demand ratios of various services within the zone.