| With the rapid development of society and economy,the increasing influence of human activities has led to a series of over-exploitation of territorial space resources,resulting in the intensification of conflicts between natural ecology and social ecology,the degradation of vegetation,the destruction of wetlands,water shortage and a series of other ecological degradation problems are increasingly prominent,regional ecosystem services are reduced,and the ecological security of territorial space is facing great challenges.In order to solve the increasingly serious ecological problems,enhance ecosystem services and ensure ecological security of the territorial space,ecological restoration as a positive human response to ecological degradation problems,is imperative.Scientific and reasonable ecological restoration zoning is a necessary prerequisite for ecological restoration,providing guidance and necessary protection for the implementation of ecological restoration projects and the overall enhancement of benefits,and has attracted the attention of academics and government departments.However,The study of ecological restoration zoning is still in its beginning stage and there are many shortcomings that need to be improved,for example,the guiding role of ecological restoration zoning on ecological restoration activities at all levels is not specified,the combination of quantitative and qualitative indicators is lacking,changes in ecosystem services are ignored,and the potential and direction of ecological restoration cannot be reflected,etc.Therefore,this paper proposes a three-level zoning framework that points to "ecological restoration background-ecological restoration potential-ecological restoration direction",and applies it to the Hexi region of Gansu Province.Firstly,the elevation,slope,topographic relief and land use pattern are selected as the level-1 zoning indicators,and the level-1 zoning is carried out with reference to the zoning standards of Gansu Province’s geomorphological units.Secondly,using the equivalent factor method to evaluate ecosystem services in two phases(2005 and 2020),the change value of ecosystem services from 2005 to 2020 is used as the level-2 zoning indicators,and the level-2 zoning is obtained through hotspot analysis.Thirdly,qualitative analysis was conducted on the types and intensity of soil erosion,the degree of human interference,and the average ecological investment in the Hexi region,and level-3 zoning attempt was made.Finally,the ecological restoration strategy of Hexi region was discussed according to the level-1,level-2 and level-3of ecological restoration zoning.The results of the study show that:(1)The level-1 zoning can be divided into the Mazong Mountains,the Heli-Longshou Mountains,the Corridor Plain,the Corridor Desert and the Qilian Mountains.The Mazong Mountains and the Heli-Longshou Mountains are located in the northern part of the Hexi region and both consist of a series of intermittent low mountain systems.The Mazong Mountains are part of the eastern extension of the Tianshan Mountains and run east to west,with a topography that is high in the middle and low in the north,south-west and north-east.The Corridor Plain and the Corridor Desert are located in the central part of the Hexi region.The Corridor Plain is located in the lowland part between the Qilian Mountains and the Mazong Mountains,and the Corridor Desert is mainly located south of the Alashan Plain,adjacent to the Badanglilin Desert and the Tengri Desert.The Qilian Mountains are located in the southern part of the Hexi region,with a high topography in the west and a low topography in the east,and a complex mountain system,which can usually be divided into three sections:east,middle and west,and are the main source of the three major inland rivers in the Hexi region.(2)The value of ecosystem services in the western part of the river is high in the south and low in the north,high in the east and low in the west,and ecosystem services are mainly provided by supporting and regulating services.From 2005 to 2020,the value of ecosystem services in Hexi region is increasing steadily,with the largest proportion of unchanged areas and a concentration of increasing and decreasing areas,the increasing areas being mainly in the glacial areas in the western part of the Qilian Mountains and the forested grasslands in the upper reaches of the Shiyang River basin.The increase was mainly in the glaciated areas in the western part of the Qilian Mountains and the forested grasslands in the upper part of the Shiyang River basin,while the decrease was mainly in the grasslands in the middle part of the Mahaishan and Qilian Mountains and the oasis cities in the Corridor Plain.There are 11level-2 zoning: the Mazong Mountains can be divided into the Mazong Mountains Potential Restoration Area and the Mazong Mountains Important Restoration Area,the Heli-Longshou Mountains can be divided into the Heli-Longshou Mountains Potential Restoration Area and the Heli-Longshou Mountains Important Restoration Area,the Corridor Plain can be divided into the Corridor Plain Potential Restoration Area and the Corridor Plain Important Restoration Area,the Corridor Desert can be divided into the Corridor Desert Potential Restoration Area and the Corridor Desert Important Restoration Area,and the Qilian Mountains can be divided into the Qilian Mountains Potential Restoration Area,Qilian Mountains Important Restoration Area and Qilian Mountains Important Conservation Area.Among them,the restoration potential of the Mazong Mountains Important Restoration,the Heli-Longshou Mountains Important Restoration Area,the Corridor Plain Important Restoration Area,the Corridor Desert Important Restoration Area and the Qilian Mountains Important Restoration Area is greater,the Qilian Mountains Important Protection Area tends to be ecologically protected,and the rest of the areas all have less ecological restoration potential.The distribution of important restoration areas in the Hexi region is more complex than that of protected areas,so the direction of ecological restoration will be more diverse than that of conservation,but ecological conservation is more urgent in the Hexi region than restoration,as evidenced by the fact that the area of important protected areas is larger than that of important restoration areas.(3)Soil erosion in the western part of the river is mainly hydraulic,wind and freeze-thaw erosion,hydraulic erosion is mainly distributed in the southern Qilian Mountains,less in the Heli-Longshou Mountains,freeze-thaw erosion is mainly concentrated in the glacier area of the Qilian Mountains,wind erosion is mainly distributed in the northern Mazong Mountains,Heli-Longshou Mountains and the central corridor plain and corridor desert,a small amount is distributed in the western and central Qilian Mountains,the degree of anthropogenic disturbance is high in the north and low in the south The average ecological investment in the area is roughly characterised by a low north-south and high middle.This results in 15 level-3zoning,namely the Mazong Ecological Precautionary Zone,the Mazong Ecological Construction Zone,the Longshou Ecological Precautionary Zone,the Hailishan Ecological Precautionary Zone,the Longshou Ecological Construction Zone,the Plain Ecological Precautionary Zone,the Plain Urban Ecological Construction Zone 1,the Plain Urban Ecological Construction Zone 2,the Desert Ecological Precautionary Zone,the Desert Urban Ecological Construction Zone,the Qilian Mountains Ecological Precautionary Zone 1,the Qilian Mountains Ecological Precautionary Zone 2,the Qilian Mountain Ecological Construction Zone,Qilian Mountain Eastern Reserve and Qilian Mountain Western Reserve.(4)The Mazong Mountains should focus on wind and sand control,preventing the lowering of ecosystem services caused by the increased sanding of large areas of land,relying on natural forces to restore vegetation,supplemented by artificial management and cultivation measures to gradually increase vegetation cover,strict water resource management systems,and water ecological restoration.The Heli-Longshou Mountains should strengthen the construction and protection of grasslands,carry out afforestation and grass planting on unused land,build a northern sand control belt to prevent the invasion of the desert in the north,protect the grasslands in front of the mountains,strengthen the management around grassland patches and improve the vegetation cover.The Corridor Plain should promote the planting of desert vegetation,improve the ability to prevent wind and fix sand,work towards extending the edge of the oasis,increase capital investment,protect arable land and grassland,focus on controlling human development and construction activities,promote urban greening and parkland,and push forward the project of returning grazing to grass and grassland ecological restoration and treatment.The Corridor Desert should manage the sanding of the land,gradually pushing forward from oasis edge management to deep desert management,increasing financial investment in managing the Gobi desert area,promoting comprehensive agricultural land management,controlling the process of urban expansion,carrying out artificial afforestation and grass planting,and can appropriately develop fruit and forest agriculture,and protecting the water resources of the oasis is also the key to oasis prevention and control of desertification.The Qilian Mountains should implement restoration and protection restoration measures,appropriately increase financial investment,strengthen the protection of natural forests,implement management and protection of the glaciers and rivers in the Qilian Mountains,promote the pilot work of the Qilian Mountains National Park,close the glacier area,implement ecological migration relocation for residents in protected areas,implement seasonal rotation of grazing in mountainous grasslands,combine the characteristics of high mountain areas,implement the return of cultivated land to forest and grass on high slopes,carry out artificial afforestation and The park has also taken measures to strengthen the construction of protective forests for soil and water conservation on slopes,and to transform low and middle-yielding fields and improve the quality of arable land. |
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