Study On Ecological Restoration Zoning Of Zhanjiang City Based On Ecological Service Function Evaluation

In recent years,with the rapid development of China’s economy and the advancement of urbanization,a large area of agricultural,forestry,and grassland land has been converted into construction land,directly damaging the local ecological environment.Zhanjiang,as the area with the most abundant solar and thermal resources in China,has always been an important tropical crop production base in China.However,driven by the economic reform of reform and opening up for many years,the economic and social development level and urbanization level of Zhanjiang City have improved to a certain extent,but correspondingly,the contradiction between land use and water supply and demand in Zhanjiang City has become increasingly prominent,with serious soil erosion,gradual decline in the quality of cultivated land,biodiversity and forest vegetation coverage This means that the ecological security situation in Zhanjiang is extremely serious.Taking Zhanjiang City as the research area,based on the Invest model,using Arcgis Spatial analysis software,Barrier Mapper tool and other tools as aids,combined with multi-source data such as climate,soil,elevation and land use,this paper quantitatively simulates four ecosystem services in Zhanjiang City in 2000,2010 and 2020-water conservation,soil conservation,carbon storage and habitat quality,and analyzes their spatio-temporal characteristics,At the same time,the correlation between service function changes and land use changes was analyzed based on land use transfer data.On this basis,construct ecological restoration zones and propose corresponding goals and strategies.The research results indicate that:(1)The four ecosystem service functions of Zhanjiang City have obvious temporal and spatial differences.Compared with 2000,the area of low value areas for water conservation increased by 23.1%in 2020,and the water conservation function in the eastern region gradually weakened.The lowest soil retention time distribution in 2020 was 1242663.5 t/Km2.During the period from 2000 to 2020,the soil conservation function of Zhanjiang City showed a downward trend as a whole.In terms of carbon storage,the carbon storage in 2000 was 53.5 t/ha,in 2010 it was 43.2 t/ha,and in 2020 it was 38.8 t/ha.Overall,carbon storage has shown a decreasing trend year by year.In terms of time,the overall changes in regions with high carbon storage levels are not significant,with the main problem being the increase in low carbon storage areas in the eastern and northern regions.In terms of temporal distribution,areas with lower levels of biodiversity have increased significantly,while in terms of spatial distribution,biodiversity in the eastern built-up areas has decreased significantly.(2)Land use transfer has a greater impact on the ecosystem services of Zhanjiang City.The area of low value areas for water conservation increased by 23.1%.The amount of soil conservation has also decreased to a certain extent,mainly due to the transfer of large areas of arable land to construction land,which greatly reduces the soil’s ability to retain water and fix soil;The decrease of carbon storage year by year is related to the decrease of forest land and the increase of construction land in land use transfer,because the biomass carbon originally existing in forest land is released or transferred to other land use types,which is an important basis for ecological service function status in the division and evaluation of ecological restoration zoning in Zhanjiang City.(3)With the help of ArcGIS Spatial analysis software,qualitative analysis was carried out in combination with literature data,and comprehensive ecological service function evaluation was conducted to identify the ecological pinch points,ecological obstacles and Wildlife corridor with the biodiversity evaluation results as the ecological source.The results show that besides the urban area and Suixi County,there are 38 large ecological pinch points in Zhanjiang,totaling 801 locations,which are mainly distributed in the northern region,of which the ecological pinch points in Shijiao,Heliao and Tangpeng are relatively concentrated.The pinch points in the southern region are mostly located in mountainous forests,with a relatively complete ecological protection system and high landscape connectivity.On the contrary,due to the frequent impact of human activities,the central and eastern regions have identified 18 ecological obstacles,which are distributed in municipal districts,Xuwen County and Leizhou City,resulting in the lack of Wildlife corridor and serious ecological problems in the central and eastern regions.This part of the content is an important basis for Spatial analysis when judging the restoration zoning of Zhanjiang City.(4)On the basis of the core goal of improving the ecological security guarantee ability of Zhanjiang City,the ecological restoration zoning was divided,and finally the ecological restoration zoning of Zhanjiang City was divided into five zones,namely,the northern ecological conservation zone,the central ecological reconstruction zone,the southern ecological governance zone,the coastal ecological protection zone,and the modern ecological agriculture zone.Remediation strategies have been proposed for the core issues within different zones.Among them,the northern ecological conservation area focuses on the restoration of forest resources,striving to restore the stability and integrity of the forest ecosystem;The central ecological reconstruction zone focuses on improving the quality of life of urban residents and strengthening the construction of forest parks and nature reserves around the city;The southern ecological management zone strictly controls and repairs the existing mountain forests for Secondary forest and residual forests;The coastal ecological protection zone is mainly responsible for the restoration and expansion of coastal protective forests;Modern ecological agricultural areas focus on the issue of soil quality decline,remediation and treatment of contaminated soil,in order to restore agricultural production capacity.(5)From the perspectives of research content,research scale,and research objectives,the evaluation of ecosystem service functions can meet multiple strategic needs for land spatial ecological restoration,providing theoretical and methodological support for land spatial ecological restoration.The empirical results of ecological restoration zoning in Zhanjiang City show that the use of Invest model to evaluate the value of ecosystem services can accurately guide the ecological restoration work and promote the maximization of the value of land space ecosystem services.