The Construction of an Ecological Function Network and Its Application in the Greater Bay Area, China

Ecological security patterns are important for the optimal allocation of ecological resources, and for restricting the expansion of cities. In order to implement effective protection for maintaining ecological safety in urban agglomeration, it is important to plan and support regional green space. Currently, technical difficulties in studying ecological security patterns are linked to the identification of ecological sources and the construction of spatial resistance surfaces. RS and GIS technology were used to identify ecological landscape types and landscape patterns in the urban agglomeration of the Greater Bay Area using data from 1980, 1995 and 2010. Ecological source patches were identified by evaluating ecosystem service importance. A regional ecological network was constructed using the minimum cumulative resistance model and the layout of eco-spatial structure in the region was optimized. Results show that: (1)forestland was the dominant landscape in the study area. The land-use landscape tended to be unstable, with fragmentation increasing and the index of COHESION and AI of farmland and forestland decreasing; (2)the area of ecological sources was approximately 2 638.3 km², with the ecological source areas accounting for 9% of the forestland. The key ecological corridors, distributed in a branch shape with a radial pattern, were 705 km long. Although the overall ecological environment has improved, distribution was uneven, especially for the connectivity of the ecological corridors to the east of the Pearl River area; (3)in order to enhance the integrity and penetration of the natural ecosystem, it is proposed that to construct a high quality continuous forest based on the northern mountainous ecological barrier and the southern coast forest. At the same time, it is important to coordinate the construction of a cross-regional forest barrier belt to improve connectivity of ecological sources and to enhance regional ecosystem services.