Constructing and optimizing the ecological security pattern in the Sanjiang Plain based on ecosystem services and ecosystem health

In response to accelerating ecological degradation and land-use conflicts in Northeast China, this study constructs a comprehensive Ecological Security Pattern (ESP) for the Sanjiang Plain by integrating ecosystem services (ES) and ecosystem health (EH) indicators. We quantified six critical ES—including food production, carbon storage, soil retention, water yield, water purification, and habitat quality—using remote sensing and ecological models. Simultaneously, we assessed EH through indicators of ecosystem vigor (net primary productivity), organization (landscape metrics), and resilience (land-use-based recovery coefficients), combining them into an integrated ecological security index. Ecological sources were identified using natural breaks and minimum patch size thresholds, while resistance surfaces were derived from land use, topography, NDVI, and human disturbance factors. Circuit theory was employed to model ecological corridors, current density, pinch points, and barriers, delineating zones for prioritized restoration. Results show a spatial structure dominated by north-south corridors with cross-cutting east-west linkages. High-value ecological sources are concentrated in the eastern and southern margins, while central regions face severe connectivity fragmentation due to agricultural and urban expansion. Based on spatial overlap among corridors and ecological bottlenecks, we propose a four-tier zoning framework: ecological conservation priority zones, ecological restoration priority zones, ecological security control zones, and ecological function enhancement zones. This study offers a systematic, multi-scalar paradigm for regional ecological planning and provides actionable strategies for landscape sustainability in agro-wetland mosaics.