From Fig. 6, we can see that the extremely important ecological
land is mountains and mainly located in the north and east of study
area. These areas mainly consist of the core areas of river systems,
wetlands, nature reserves and forest land, and the protection zones
of soil erosion, which are the ecological barrier for maintaining
homeland security. There are high vegetation cover, rich biodiversity, and weak resistance to natural disasters in the areas of extremely important ecological land, where man-made disturbances can not afford. The area of the extremely important ecological land is 96,025.68 hm2
, accounting for 30% of the total
area, which are the ecological“red line”for the maintenance of
regional eco-security and should be strictly protected and included
in prohibited exploitation zone, and prohibited any exploitation
and construction activities. The concept of the ecological“red line”
is established to provide more space provided for nature to restore
itself. Ecological “red line” requires all regions to optimize,
prioritize, restrict, or prohibit their industrial development
Fig. 5.Results of evaluation of ecological importance for single security in Xingguo county.
10 H. Xie et al. / Ecological Indicators 51 (2015) 3–12
according to their defined nature