| For a long time,due to urban sprawl and unreasonable land development and utilization,a large amount of natural space has been occupied,and construction land has occupied the ecological space in the city to varying degrees.However,the expansion of construction land is too fast and neglects the quality of urbanization development,resulting in the increasing fragmentation of regional ecological patches,the destruction of urban ecosystem structure and function to a certain extent,and the contradiction between development and protection is becoming more and more obvious.The continuous promotion of the construction of ecological civilization has put forward higher requirements for ecological protection.Green development is imperative.Ecological security pattern can protect the ecological environment and promote green development.Meanwhile,the conflict between reformation and protection should be effectively balanced in space,and effectively avoid the blind protection and inefficient protection of ecological protection.Building a perfect urban ecological security pattern can increase the connectivity of urban ecological space,improve the stability of the ecosystem,promote the ecological efficiency of the green space system,and guide the rational development of urban space.The research area of this article is Yuanzhou District,Jiangxi Province.Yuanzhou District,located in the west of Jiangxi Province,is the central urban area of Yichun City,with superior natural environment,forest coverage of more than 60%,and good ecological background,which is conducive to agricultural and forestry production.In recent years,due to the rapid development of land prodoction and real estate in Yuanzhou District,the excessive expansion of construction land has taken up a large amount of cultivated land and woodland.However,in order to maintain the red line of cultivated land,the local government has transformed forest land into cultivated land,and the area of forest land has decreased significantly,resulting in serious ecological and environmental problems.Based on this background,different dimensions of landscape index were selected to analyze the landscape pattern and its changing process,then construct a model to evaluate ecological security;The morphological spatial pattern analysis method(MSPA)is used to identify the core area and determine the alternative ecological source areas.The minimum cumulative resistance model(MCR)is used to obtain the minimum path to obtain potential corridors.The landscape ecological security pattern in the study area is constructed,and relevant indicators are used to comprehensively evaluate the ecological security pattern.In the end,countermeasures for optimizing the ecological security pattern are proposed,the main research results are as follows:(1)In the process of determining the optimal analysis granularity of the landscape pattern index,the granularity effect of the landscape pattern index is obvious.Eighteen indexes were picked for analysis from two aspects of plate type level and landscape level.It was found that the landscape pattern index changed most sharply within the range of10-50 m,and 30 m was the best granularity for the analysis of landscape pattern in Yuanzhou District.Among the landscape areas in Yuanzhou District,the forest area is the largest and the water area is the smallest.The construction land and water area are relatively concentrated,while the unutilized land is relatively widely distributed.The forest land and cultivated land landscape are characterized by overall dispersion and local concentration.The overall dominance of the landscape in Yuanzhou District is not obvious,and the fragmentation is high.The spatial differentiation of the landscape pattern indexes is obvious,and the landscape connectivity is reduced.(2)In the assessment of landscape ecological security,the overall landscape ecological security of Yuanzhou District increased year by year from 2000 to 2020.The expansion of construction land in the first stage is relatively blind and wanton,and develop a great quantity forest land and cultivated land to build cities,improved the level of landscape ecological risk,made the lower ecological security area from 192.68km2 increase to 295.12km2.High ecological safety zone from 626.44km2 reduced to 584.39 km2.In the second stage,due to the strict implementation of relevant protection policies,the expansion of construction land began to become stable and orderly,the city began to focus on compact development,and the connectivity and regularity of construction land patches improved,which promoted the impact of the expansion of construction land in the second stage study area on the landscape ecology to be improved,and the area with higher ecological security increased from 802.58km2 in 2010 increase to 909.39km2,the area of low safety area also ranged from 241.98km2 reduce to 216.17km2.The proportion of high and high landscape ecological security zones in the total area increased from 58.14% in2000 to 59.43% in 2020.From the perspective of space distribution,the landscape ecological security index of Yuanzhou District is higher in the southern and northern regions,and the low ecological safe area is mainly concentrated in the central urban area,namely the urban area and Xiapu Street.(3)In the construction of ecological security pattern,on account of the MSPA method and the landscape connectivity evaluation results,the ecological source areas were initially determined within the forest land in the high and high ecological security areas in 2020,and a total of 14 ecological source areas were determined considering the natural reserves with good service functions and variety of organisms in Yuanzhou District.The total area accounts for 28.65% of the land area of Yuanzhou District.The resistance surface is segmented into five grades by the natural breakpoint method,30 potential corridors in the study area were identified by the minimum cumulative resistance model and the Linkage Mapper tool,and 18 important corridors and 12 general corridors were classified by the gravity model,with a total area of 1995.12 hm2,it accounts for 0.78% of the total area of the study area.Based on the hydrological analysis,18 nodes were identified,which together constitute the ecological security pattern in Yuanzhou District.On this basis,countermeasures are put forward from the aspects of ecological source protection,ecological corridor optimization,and ecological node strengthening. |
PDF Full Text Request