Promoting ecological restoration of deeply urbanized hilly areas: A multi-scale ecological networks approach

With the deep expansion of urbanization, contradictions between human beings and the natural environment in hilly areas have shown the characteristics of multi-scale and complexity. The traditional construction of ecological network rarely focused on the relationship between ecological elements at different scales, which made it difficult to systematically solve the ecological problems. To address the gap, this paper proposed a novel framework to construct multi-scale ecological networks based on the discussion of the ecological environment problems at different space scales. Firstly, one of the most deeply urbanized hilly area in China (ChangshaZhuzhou- Xiangtan urban agglomeration, CZXUA) was chosen as the study area. By constructing the multi-scale evaluation system of ecological patches importance (EPI) after conducting the Morphological Spatial Pattern Analysis (MSPA), the identification method of ecological sources was optimized at different scales. Then, spatial principal component analysis (SPCA) was used to sort out the resistance factors at different scales, and the multiscale resistance surfaces was constructed accordingly. Furthermore, the multi-scale ecological networks from the CZXUA to the central urban area were cooperatively constructed through the Least-cost path (LCP), circuit theory, hierarchical transmission and scale nesting. Finally, based on characteristics of the ecological networks at different scales, the study constructed the overall ecological security pattern in urban agglomeration, the ecological space development framework in metropolitan area and the green open space system in central urban area, which was well applied to the territorial space planning at different spacial scales. The results made up for the deficiency of single-scale ecological network in neglecting the important details of local areas, and provided a feasible ecological restoration plan for the decision makers and practitioners. This study can contribute to crossscale ecosystem restoration and biodiversity conservation in hills.