| With the acceleration of the social development process,the disorderly spread of urban land and the irrational use of land are increasing,which results in the tremendous changes of the regional hydrological climate,biodiversity,and ecological cycle,triggering a series of ecological and environmental problems such as climate anomalies,soil erosion and soil pollution,and drastic reduction of the number of animals and plant,and destroying the functions and structures of natural ecosystem services.The continuous deterioration of the ecological environment has brought about more and more negative effects on the social and economic development,and has caused a negative impact on the healthy and stable development of regional socio-economic.Therefore,it is of great significance for regional economic development to optimize the spatial pattern of landscape ecological security and strengthen the protection of ecological environment.At the same time,the research on the spatial pattern of ecological security can not only provide reference for the protection of ecological environment,but also have reference significance for the protection of biodiversity and the stabilization of ecosystem structure in regional landscape ecological security.This paper chooses the Wanzhou District,a typical ecologically fragile city in the Three Gorges reservoir area,as the study object and then discusses Spatial and temporal changes of ecosystem services in Wanzhou District.Based on this,it considers source identification and landscape ecological resistance factors comprehensively,and using MCR model to construct landscape ecological security pattern,and then put forward corresponding protection strategies.The results are of great significance for maintainingthe long-term stability of regional ecosystem and its service functions,enriching the technical methods of landscape ecological security pattern planning in special geographical environment,and promoting the coordinated development of social and economic development and ecological environment protection in the reservoir area.The main results of the study are as follows:(1)Based Based on the study of land use change pattern in Wanzhou District,the results show that the land use change in Wanzhou District is more significant.Forest land and cultivated land,as the main dominant land use types in Wanzhou District,account for a larger proportion of its area.From 2009 to 2016,the urban villages,industrial and mining land and transportation land in Wanzhou District showed a gradual increase trend,forming a spatial expansion pattern that spreads from the central urban area to the surrounding towns.Besides,Land use types,such as garden land,forest land,grassland,water area and other land use,have changed in varying degrees.From the dynamic change,the land use types in Wanzhou District changed significantly during the study period.The dynamic change of urban villages,industrial and mining land,other land and transportation land is the most obvious,which also shows that the study area has accelerated the development and utilization of land and made some land use types change.From the landscape pattern analysis,the overall landscape is fragmented while landscape patch types tend to be regularized.Besides,the dominance of landscape patch types gradually decreases while the heterogeneity of landscape is enhanced,and the landscape types are becoming diversified and homogenized.(2)Based on the improved Equivalent Scale of Ecosystem Service Value and the actual situation of Wanzhou District,this paper revises the existing coefficient of ecosystem service value per unit area,and finally forms the value of ecosystem service function per unit area in Wanzhou District.On this basis,the value of ecosystem service function in Wanzhou District is calculated and analyzed,and the revised single is verified by using the ecological sensitivity index.The results show that: from 2009 to2016,the value of ecosystem service function in Wanzhou area shows a downward trend,the changes in the value of ecosystem services is significant;from the ecosystem types,the value of forest ecosystem service function is the highest,while the value of water area decreases the most,and the value change rate and coefficient of variation of other land and traffic land are the largest;from the ecosystem service function,the value of the hydrology of regulating service function is the most,and the value of waterresources supply function is the least.The spatial and temporal changes of ecosystem service function value in Wanzhou District indicate that there are differences and imbalances in the value of ecosystem service function in the villages and towns of Wanzhou District during the study period,mainly reflected in the great changes in the value of ecosystem service function in the central urban area and the surrounding town boundaries,and the small changes in other villages and towns.In terms of spatial distribution,the value of ecosystem services in Wanzhou District is generally high in the central and southern regions,and low in the western and northeastern regions.The number of towns with low value of ecosystem services decreases gradually,and the value of ecosystem services in Wanzhou District tends to develop benignly.(3)The origin of landscape ecological security pattern was established from three aspects: landscape patch,landscape external response factors and landscape connectivity.The resistance surface was constructed by selecting resistance surface indexes from landscape itself and external factors.The minimum cumulative resistance surface was established by using MCR model,and the landscape ecological security spatial zoning was carried out according to the minimum cumulative resistance surface.According to the results of landscape ecological zoning,the area of ecological protection area is 79231.39 hectares,accounting for 22.92% of the total area.As the core area of landscape ecological security pattern,ecological protection area mainly plays the role of ecosystem services.Forest land and water area are the main landscape types of ecological protection area,mainly concentrated in the northwest,southeast and central part of the region;the area of ecological buffer area is 53037.48 hectares,accounting for 15.35% of the total area of the region.Eco-buffer zone is mainly to assist the ecological protection zone to play its maximum ecosystem service function.As an important type of ecological buffer zone,woodland and arable land mainly distribute in the periphery of the ecological protection zone.The area of eco-sensitive zone is84980.23 hectares,accounting for 24.58% of the total area of the region,and the eco-sensitive zone as an important transitional zone between eco-buffer zone and eco-plastic zone,is mainly to maintain the balance of landscape ecology in ecological protection,agricultural production and urban construction activities.Forest land,arable land and grassland constitute the main landscape types,which mainly distribute in the northwest,central and eastern parts of the region.The area of eco-plastic areas is128388.5hectares,accounting for 37.15% of the total area of the region,and theeco-plastic areas,as the outer layer of the sensitive area,is the main area of human activities.The cultivated land,town,village and industrial and mining land are the main types of land.(4)The overall framework of landscape ecological security pattern in Wanzhou District is as follows: taking high value area of ecosystem service function,important habitats,large-scale ecological land and ecological patches with good landscape connectivity as important landscape ecological sources.Combining rivers,roads and forest corridors,the landscape ecological corridors of "five horizontal and three vertical" are designed.Ecological corridors and ecological nodes eventually constitute the landscape ecological network space of Wanzhou District.The overall structure of landscape ecological security can be summarized as "five horizontal,three vertical,multi-point and four districts".On the basis of landscape ecological zoning and ecological security pattern in Wanzhou District,this paper puts forward corresponding protection strategies from the aspects of strengthening the protection of ecological sources,implementing and perfecting the strategy of landscape ecological security zoning,and attaching importance to the construction of ecological corridor and ecological network of strategic points. |
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