Abstract: Optimizing the spatial patterns of urban expansion and ecological space is an urgent need in toplevel design of land development. As a method for reconciling conflict between ecosystem conservation and urban exploitation, ecological security pattern (ESP) construction is important to improving the efficiency of land consolidation in ecological shelter zone, which is characterized by ecosystem diversity and ecosystem services. Chengde in Hebei Province is an ecological barrier area in the north of Beijing and Tianjin. According to the results of ecosystem services evaluation, we identified the most important zones of forest, shrubland, and grassland, and designated the ecological sources in combination with existing protection areas in Chengde. ESP was constructed based on minimal cumulative resistance (MCR) model. The area of identified ecological sources was 13200 km², accounting for 34.22% of total area. The ecological corridors were 2160 km, including cluster corridors and landscape corridors, which were distributed in pattern of one horizontal direction (Wuling Mountain-Dushan Mountain) and three vertical directions (Liaohe headwaters-Maojing Dam, Baicao Depression-Yudao Pass, Baicao Depression-Luanhe headwaters). The corridors effectively linked up the ecological sources. In total, 22 ecological nodes were identified, which could be classified into two types as core nodes and stepping stone nodes. The areas of high and low-level ecosecurity buffer zones were 12550 and 11352 km². Compared with the status and planning of land-use, most natural vegetation was effectively conserved, and the ESP was generally consistent with the pattern of Chengde’s environment protection and urban development strategies. The results indicated that the improved method reduced the uncertainty of ESP resulted from heterogeneous vegetation distribution and difference in net primary productivity among different vegetation types, and had well applicability in ecological shelter zone. Our results provide scientific guidance and technical support for territorial development and environment protection in ecological shelter zone.

Key words: ecological security pattern, ecological shelter zone, minimal cumulative resistance.