Regional Ecological Security Pattern Construction Based on Ecological Barriers: A Case Study of the Bohai Bay Terrestrial Ecosystem

The construction of ecological barriers and ecological security patterns is an important way of maintaining regional ecological security in landscape ecology. However, there is still no consensus on the concept and connotation of ecological barriers, and the zoning and adaptive management of ecological sources are rarely considered in the construction of ecological security patterns. This study uses the terrestrial ecosystem of Bohai Bay, China as a study area, and the identification and zoning of ecological sources in the ecological security pattern are achieved by combining an ecosystem service assessment with an ecological risk assessment, and on this basis, ecological barriers are identified to optimize the structure and function of ecological sources. The minimum cumulative resistance model is used to identify ecological corridors and ecological strategic nodes and to construct an ecological security pattern based on the modified ecological sources. The results demonstrate that firstly, 2873.25 km(2) was identified as the ecological source, accounting for 14.28% of the total. Secondly, there are three large ecological barrier zones and nine ecological barrier cells with a total area of 1173.06 km(2), accounting for 40.83% of the ecological sources. Thirdly, a total of 35 ecological corridors were extracted, and 32 ecological strategic nodes were marked, mainly distributed at the intersection and branches of important ecological corridors. An ecological security pattern construction system was formed with the collection of ecological source selection, ecological barrier identification, ecological resistance surface construction, and ecological corridor extraction. Fourthly, the concept and connotation of ecological barriers was analyzed, and the complementary relationship between ecological barriers and ecological security patterns in terms of structure and function is discussed. This study enriches the definition and connotation of ecological barriers, provides a new framework for identifying the ecological security patterns, and provides scientific guidance for ecological protection and management in coastal areas.