Research On Ecosystem Service Function And Network Optimization Of Nanping City Based On Ecological Landscape Pattern

Ecosystem service function is an important factor that characterizes the regional ecological environment.As an important national ecological barrier,the evaluation of ecosystem services and the construction of ecological networks can provide important references for the ecological environment planning and sustainable development of Nanping City.Firstly,based on the MSPA and InVEST models,the research evaluated the spatial and temporal evolution characteristics of the ecological landscape pattern and ecosystem service functions of Nanping City from 2009 to 2017;Then based on the CLUE-S model,the research simulated the land use in 2025 under the natural development scenario and the ecological protection scenario,and predicted ecosystem service functions under the two scenarios,conducted trade-off and coordination analysis between ecosystem service functions;Finally,this study constructed potential ecological corridors on the basis of comprehensive landscape pattern and ecosystem service functions by using MCR model,optimized and evaluated the matrix,corridors and nodes of the ecological network structure of Nanping City,and provided theoretical basis for the planning and construction of the ecological network of Nanping City and the improvement of ecological service functions,as well as ecological protection and ecological corridors in other regions.Planning provides reference.The main findings are as follows:(1)The ecological infrastructure in 2009-2017 was mainly the core area,mainly concentrated in the Wuyishan Nature Reserve,Mangdangshan Nature Reserve,etc.The central and southeast core areas were less and less distributed in the region.The bridge were scattered around the core area.The area of isle and loop accounted for less than 1%,and they were obviously affected by the branch.There were many breakpoints in regional ecological corridors and the area of internal migration channels for species was small.The proportion of perforation was always higher than 5%,indicating that there were still edge effects in the region.Combined with the landscape connection level index,the results showed that the areas with higher d PC were mainly located in the Wuyishan Nature Reserve and Kuangshan Nature Reserve.The northern area had a large ecological source area,low fragmentation.The central region had low landscape connectivit,with high resistance to species migration.The ecological source areas in the west need to improve patch integrity and connectivity.(2)From 2009 to 2017,the results of the temporal and spatial change characteristics of the ecosystem service functions of Nanping City showed that the average habitat quality of Nanping City had an overall downward trend,and the spatial distribution of habitat quality was significantly different,manifested as a decreasing trend from the surrounding area to the central region.The habitat quality in the northwest was higher than other regions.The low habitat quality areas were concentrated in the middle and lower reaches of the densely populated watershed,with urban areas as the core of low habitat quality spread outward;from the perspective of the temporal and spatial distribution characteristics of soil conservation,the soil retention showed a trend of first decreasing and then increasing,and the total amount of soil retention increased by 18.71×10⁸ t·a^-1.The spatial distribution of soil retention was obviously different,mainly presented the characteristics of high around and low in the middle.The high-value areas were concentrated in the northern Wuyi Mountain Reserve and the southeast Jiufeng Mountain with high patch connectivity.The ability of soil retention was good,and the low-value areas were mainly distributed in areas with an altitude less than 300m,the ecological environment was relatively fragile;from the perspective of the temporal and spatial distribution of water yield,the total water yield increased by6.16×10⁹mm,and the water yield showed a slight decrease and then an increase trend.The spatial distribution presented a trend of high in the north and low in the south,which was consistent with the distribution of the precipitation,more in the northwest and less in the south(3)Compared with the natural development scenario,the average habitat quality of the ecological protection scenario was improved by 0.05,and the spatial distribution showed that it was high in the northwest,low in the middle and the southeast.The Kuangshan Forest Park and the Mangdangshan Nature Reserve had changed significantly,they can changed from general degradation to less degradation,followed by the southern part of Yanping District,where the degradation transformed from severe degradation into general degradation;from the perspective of soil retention,the soil retention in the natural development scenario was lower than that of the ecological protection scenario,the spatial distribution was characterized by high in the north and south and low in the middle.Among them,the amount of soil retention in Wuyishan City changed significantly;from the perspective of water yield,the water yield under the ecological protection scenario decreases,showing a trend of decline in the northwest and southeast to other regions.In the ecological protection scenario,the water yield of woodland had declined,while the grassland and gardens had increased.Through weighing and synergistic analysis of ecosystem service functions in the two scenarios,it served as the scientific basis for ecological network optimization.The results showed that there was a synergistic relationship between soil retention and habitat quality,soil retention and water yield,habitat quality was a trade-off relationship with ecological degradation and water production,and ecological degradation was a trade-off relationship with soil retention and water yield.(4)Based on the ecosystem service function,the study extracted 15 potential ecological corridors,with 9 important ecological corridors and 6 general ecological corridors extracted using the gravity model.The overall spatial distribution was uneven,the corridors mainly concentrated in the northern area and extending to the south area,it was distributed in a triangular network.Then the ecological network was optimized through matrix-corridor-node,the networks added 11 ecological sources,136 ecological corridors,and 1019 ecological breakpoints and 1481 stepping stones were repaired.After the optimization of networks,?index,?index and?index are 0.45,1.86,and 0.64,respectively.It showed that the optimized ecological network structure was more perfect and the connectivity was better.