Synergistic ecological network approach for sustainable development of highly urbanized area in the Bay Bottom region: A study in Chengyang District, Qingdao

Rapid urbanization has put the marine environment under great threat, and cities in the Bay Bottom area are more likely to cause a large number of ecological problems in urban development and construction due to their special land-sea interaction environment. Ecological network is an effective solution to coordinate regional ecological protection and sustainable urban development. This study focused on Chengyang District, one of the highly urbanized areas at the bottom of Jiaozhou Bay in Qingdao, China, was using Morphological Spatial Pattern Analysis (MSPA) to initially identify ecological source areas and extracting important ecological source areas in conjunction with the landscape connectivity assessment, and was determining ecological resistance values based on the importance of ecosystem services, and was optimizing ecological network by the minimum cumulative resistance model (MCR) and network structure analysis. The results indicated that: (1) the habitat in Chengyang District is severely fragmented, and the ecological network structure has significant features in terms of source area, type and corridor distribution, with a low percentage of source area, identification of characteristic source types such as reservoirs, wetlands, and aquaculture ponds, while the corridors are concentrated in the area of rivers and bays, and there is fragmentation in the inland areas of the city. (2) Preliminarily, 15 ecological source sites were identified, mainly distributed in the vicinity of Jiaozhou Bay Wetland, Jihongtan Reservoir and Laoshan Mountain, among which, Jiaozhou Bay Wetland is the most important ecological source in Chengyang District. Thirty-two ecological nodes and 24 ecological corridors were constructed. (3) By increasing the inland ecological sources in Chengyang District, the optimized ecological network forms a spatial pattern of "four cores, three belts, and four districts", and proposes and formulates targeted ecological protection and management strategies to promote the sustainable development of the urban areas in the bottom of the bay. In addition, this study provides a new reference for the global ecological protection of cities in the bay area by improving the ecological network of cities in the Bay Bottom area.