Research On The Identification Of Key Areas For Ecological Restoration Of Dexing City’s Territorial Space Based On Ecological Network

Territorial space is the material basis of ecological civilization construction.In recent years,under the strategic demands of integrating"mountains,rivers,forests,fields,lakes,grass,sand and ice",territorial space ecological protection and restoration has become an important strategic task to maintain ecological security under the concept of ecological civilization construction in the new era,and an important way to improve the modern capacity of territorial space governance.Due to the prominent ecological problems in the development of resource-based cities,there are more and more researches on the object of ecological protection and restoration focusing on resource-based cities.The use of ecological network to identify the key areas of ecological restoration in resource-based cities is the strategic requirement of current ecological protection and restoration,as well as an important step to support sustainable urban development.Therefore,in this paper,ecological security assessment was carried out from the three dimensions of landscape process integrity,ecosystem service sustainability and prevention of ecological degradation.On this basis,ecological sources were identified,and ecological corridors and nodes were extracted by methods such as minimum cumulative resistance model and circuit theory to complete the construction of ecological networks and conduct evaluation;Finally,the key areas of ecological restoration were identified through Pajek and Tyson polygon,so as to provide reference for the ecological restoration of Dexing City.The main conclusions of the study are as follows:(1)Ecological security assessment based on ecosystem pattern-ecosystem quality-ecosystem services-ecosystem stress.The overall ecological security situation in Dexing City showed a significant downward trend from 2000 to 2015,but showed a slow upward trend after 2015,indicating that the ecological security situation was gradually improving.The areas with the highest ecological security level(Level 5)are mainly distributed in Damao Mountain Scenic Area and Mount Sanqing Scenic Area,with a good ecological base.The average area in five years is 44144.98 hm~2,accounting for 21.23%of the total area of Dexing City;The areas with high ecological security level(Level 4)are mainly composed of forest land,which is distributed in almost every township.The average area of the five years is 61556.47 hm~2,accounting for 29.60%of the total area of Dexing City;The lowest ecological security level(level 1)is mainly distributed in urban centers and shows a trend of annual expansion.The average area over the five years is 14416.23841hm~2,accounting for 7%of the total area of Dexing City.It can be concluded that the ecological security situation in the research area has improved in recent years,and the overall ecological security situation is good.(2)Ecological network construction based on the paradigm of"identification of ecological source-construction of resistance surface-extraction of ecological corridors and ecological nodes".In 2020,a total of 33 ecological source areas were extracted,covering an area of 77031.02 hm~2,accounting for 37.04%of the total area of the study area.They are mainly forest land,with significant spatial distribution unevenness.They are mainly distributed in Banda Township,Longtoushan Town,Damaoshan Town,and Raoer Town,while there is no source area distribution in Xiangtun Street and Sizhou Town;A total of 70 ecological corridors have been extracted,including 65 key corridors with a total length of 302.40 km and an average length of 4.32 km.There are 5 potential corridors with a total length of 82.91 km and an average length of 16.58 km,showing a trend of fewer corridors in the central region and more corridors in the surrounding areas.The density of corridors in the northern part of Xingangshan Town is the highest;A total of 21 ecological pinch points were identified,concentrated around the two major scenic spots.(3)Identification of key ecological restoration areas through Pajek and Tyson polygons.Using the Barrier Mapper tool to identify 107 ecological obstacle areas with a total area of 6509.58 hm~2,high obstacle areas are identified as key areas for ecological restoration;Based on complex network theory and Tyson polygon,6 ecological blind spots were identified,totaling 17346.61 hm~2.The ecological background conditions in this area are poor,mainly distributed in the central part of the study area;The cutting off of ecological corridors by large-scale roads and railways has resulted in 69 ecological fracture points,concentrated in the dense road network in the southern part of Xingangshan Town;On the basis of 33 ecological source areas,12 new source areas are added,totaling 2143.15hm~2,to serve as ecological restoration and improvement areas.Integrating ecological restoration obstacles,blind spots,breakpoints,and improvement areas to identify key ecological restoration areas in Dexing City and propose corresponding ecological restoration strategies will effectively enhance the balance and integrity of the ecological network.