Abstract: Against the backdrop of increasing demands for multiple ecosystem services and intensifying spatial conflicts, constructing an ecological security pattern that ensures both synergy and sustainability has become a central issue in ecological conservation and territorial spatial governance. Available methods for source area identification are mostly based on simple equal-weight overlay or entropy-weighted overlay approaches. Although being practical to some extent, these methods are limited in enhancing the efficiency of multi-service synergies and mitigating trade-offs. To address such limitations, we introduced a scenario-regulated ordered weighted averaging (OWA) model and proposed an optimization approach for ecological security pattern construction oriented toward improving service synergy efficiency. With Yan'an City, a typical ecologically fragile area in Northwest China, as a case study, we tassessed six types of ecosystem services (habitat quality, water yield, soil conservation, carbon storage, cultural aesthetics, and windbreak-sand fixation) under seven risk-preference scenarios to identify optimal synergistic sources. We used Conefor and Linkage Mapper models to construct ecological security pattern under different scenarios, and evaluated their performance in terms of source protection efficiency and corridor network topology by comparing the OWA synergy-based method with the simple overlay and entropy-weighted overlay approaches. Results showed that the OWA synergy-based method consistently demonstrated lower levels of trade-offs among ecosystem services, higher average protection efficiency, and a more favorable network connectivity structure in both 2000 and 2020, outperforming the traditional source overlay methods. The OWA synergy-based approach maintained the highest average protection efficiency in both 2000 and 2020, and performed particularly well in estimating critical ecosystem services of the Loess Plateau, such as windbreak-sand fixation and carbon storage. In terms of network topology, the OWA synergy-based pattern exhibited higher closure and node connection efficiency, indicating stronger stability and fault tolerance. These findings would provide new insights into source identification and spatial optimization under the context of ecosystem service trade-offs, and offer theoretical guidance and practical references for the delineation of ecological restoration priority areas and the planning of territorial ecological restoration.

Key words: ecological security pattern, ordered weighted averaging, source identification, ecological performance, trade-off of ecosystem service, ecologically fragile area, Yan'an City