Spatial And Temporal Variation Of Ecosystem Services,Trade-off/synergy Relationships And Functional Zoning In Jiangxi Province

In the context of population growth and continued urbanization,ecosystem services have suffered strong anthropogenic disturbance and destruction.As a result,human beings are aware of the need to rethink and adjust natural resource use to improve ecosystem service supply and mitigate ecological crises.Jiangxi Province is an important ecological barrier in the hilly region of southern China,with high forest coverage and rich ecological resources,and is a national pilot ecological civilization zone.Jiangxi Province faces the dual pressure of economic development and ecological protection.Therefore,assessing the spatial and temporal patterns and trade-offs of ecosystem services as well as the zoning of ecological functions can help to formulate ecological compensation policies and manage ecosystem services.Taking Jiangxi Province as an example,this thesis uses a biophysical model to assess the spatial patterns of water yield,food supply,carbon sequestration,soil conservation and habitat quality from 2001 to 2020 based on multi-source geographic data,and uses Theil-Sen and Mann-Kendall trend analysis to study the spatial heterogeneity of trends in five types of ecosystem services.Statistical correlations are used for ecosystem service interrelationships at provincial,municipal and pixel scales.The clustering algorithm was adopted to determine the ecological functional areas in Jiangxi Province,and the interrelationships and influencing factors of ecosystem services within each function zone were explored using the principal component analysis and random forest,and finally corresponding zoning management comments were developed based on them.The main findings are as follows:(1)From 2001 to 2020,water yield showed the spatial characteristics of high in the northeast and low in the west,with increasing high value areas.food supply was gradually expanding from the north-central plains of the study area to the surrounding low hills and gentle slopes during the study period.carbon sequestration,soil conservation and habitat quality show the spatial distribution characteristics of low in the middle and high in the surroundings,in which the high value areas of carbon sequestration increases clearly,soil conservation is relatively stable,and the high value areas of habitat quality decrease gradually.(2)The annual changes in habitat quality had a significant decreasing trend,and the proportion of significantly decreasing areas was about 60%.During the study period,food supply and carbon sequestration showed a significant upward trend,and the proportion of significantly increasing areas for both was 74% and 65%,respectively.The annual changes in water yield and soil conservation were non-significantly increasing,and both non-significantly increasing areas were found throughout Jiangxi Province.(3)For the trade-offs and synergistic relationships among ecosystem services at the global scale,the synergistic effects between provisioning and provisioning services fluctuated and increased.There were trade-offs between provisioning services and regulating and supporting services,with an increasing trend of trade-off effects related to water yield and a decreasing fluctuation of trade-off effects related to food supply.Synergies between regulating services and regulating services and supporting services decreased or remained stable.(4)The relationships between provisioning and provisioning services,regulating and regulating,and supporting services from 2001 to 2020 were synergistic in all cities of Jiangxi Province.Habitat quality and water supply showed trade-offs in each city.The rest of the relationships between ecosystem services have both synergies and trade-offs in the cities.(5)For ecosystem service relationships at the pixel scale,five groups of ecosystem service pairs dominated the relationship as synergistic.Four groups of ecosystem service pairs dominated the relationship as trade-offs,and one group of ecosystem service pairs dominated each other by both trade-offs and synergistic relationships.(6)Jiangxi Province was divided into four types of ecological function zones: key ecological conservation zones,food production zones,ecological agricultural transition zones and urban and rural living zones.In key ecological conservation zones and urban and rural living zones,relationships between ecosystem services exhibit synergies.synergies and tradeoffs between ecosystem services exist in both food production zones and ecological agricultural transition zones.NDVI,topography,soil properties and population density were key factors affecting ecosystem services in ecological function zones.Based on this,the proposals of zoning differentiated ecological management are proposed.Overall,the thesis concluded that food supply,carbon sequestration and habitat quality in Jiangxi Province showed significant trends,while water yield and soil conservation services changed more steadily.The interrelationships among ecosystem services showed significant scale effects.The division of ecological functional areas and the development of differentiated management strategies are key to improving ecosystem service provisioning and reducing trade-offs to increase synergies.