[Constructing an ecological security pattern in Shenzhen, China, by matching the supply and demand of ecosystem services]

Constructing an ecological security pattern by matching the supply and demand of ecosystem services is of great significance for Shenzhen, China. To determine the strategic positioning of sustainable development pioneers and benchmarks for human well-being in a pilot demonstration area of socialism with Chinese characteristics, we selected water yield, carbon sequestration, and recreational services to identifiy the integrated supply and demand status of ecosystem services in Shenzhen using the InVEST model, ecological supply-demand ratio, cell phone signalling data analysis, and circuit theory. An ecological security pattern based on the matching of supply and demand of ecosystem services was constructed. We further examined the impacts of different delimitation boundaries on the area and number of ecological sources. The results showed that the comprehensive ecological supply-demand ratio in Shenzhen generally showed a distribution pattern of abundant in the east and scarce in the west. Among them, water yield services met the demand in terms of quantity and spatial distribution, but carbon sequestration services can not. Recreational services met the demand in terms of quantity, but their spatial distribution was extremely uneven. We identified 25 ecological sources covering a total area of 347.62 km² and 34 ecological corridors with a total length of 346.06 km. The ecological source area was large in the east and small in the west, while the length of the corridors showed the opposite distribution pattern. Different delineation boundaries had different effects on the area and number of ecological sources. Primary, secondary, and tertiary ecological source areas cover 347.62, 520.84, and 557.58 km², respectively, showing a gradual increasing trend, the numbers of ecological sources were 25, 35, and 32, showing an increasing then decreasing trend. In Shenzhen, there were important ecological patches that were not included in the ecological control line, and some patches within the ecological control line had poor ecological sustainability. Targeted protection and management policies could be formulated based on such pattern. The results could provide spatial guidance for the delimitation of ecological management and control units in Shenzhen.