A framework for ecological restoration baseline delineation integrating geology-landscape-ecology and carbon sinks...

Degraded ecosystems urgently require a quantifiable and implementable restoration baseline under the dual pressures of human activities and natural disasters. However, the scarcity of historical samples and pronounced spatial heterogeneity render this baseline "difficult to obtain and even harder to present." In this study, we take geographic similarity as the guiding principle and construct a multidimensional coupling framework under the "pattern-process-service-sustainability" paradigm: at the pattern level, we rapidly identify the "healthy reference unit" based on geographic similarity; at the process level, we examine cross-scale feedbacks among geology, landscape, and ecology within similar units to quantify the boundaries of pattern-driven ecological processes; at the service level, we use the high carbon-sink values of these units as adjustment criteria for the baseline; and at the sustainability level, we assess the region's long-term capacity to provide carbon sinks and ecological services by integrating the above criteria. The feasibility and validity of the framework were verified using plateau lake basin in the central Yunnan as a case study. The results show that geographic similarity accurately identifies five classes of areas sharing identical geographic-environment variables. The ecological restoration baselines of restoration areas I, III, and V are distributed in the middle part of the basin, while those of restoration area II are located in the upper-middle part of the basin, and restoration area IV is concentrated along its periphery. Although the ecological restoration baselines of all restoration areas are generally situated in the upper-middle part of the basin, their precise locations are not identical. This study bridges theoretical innovation with practical needs, proposing a baseline-delineation method for ecological restoration of significant practical value. It not only offers robust support for ecological-restoration efforts in the plateau lake basin but also provides a reference for other regions grappling with complex human-land relationships and the urgent need to set restoration targets.