Study On The Transmission Mechanism And Quantitative Simulation Of Urban-rural Ecosystem Service Flow

The mobility of ecosystem services supports its ability to move spatially and temporally along with material cycles,energy flows,as well as information transfer processes,and eventually to perform its services off-site.The resource characteristics between urban and rural areas naturally determine the complex flow of ecosystem services within the urban-rural coupled system in which various ecosystem services produced in rural areas can be transferred into urban areas for human consumption with the help of natural-social drivers.However,due to the naturalness,diversity and complexity of ecosystem service flows,academic discussions on the whole life cycle movement of ecosystem services on the urban-rural gradient are still rare at this stage,reflecting the lack of theories on the transmission mechanisms and spatial patterns of ecosystem service flows.In view of this,this paper introduces the emerging academic concept of ecosystem service flows(ESFs)to explain the above phenomenon.Following the logical line of "problem focus-mechanism analysis-quantitative simulation-process governance",the study attempts to respond to the four fundamental questions of "what are ESFs","how ESFs are transmitted","how to quantify ESFs" and "how to govern ESFs".The main findings of this paper are as follows:(1)This study defines the concept of ESFs narrowly as "the potential spatio-temporal transmission of ecosystem services provided by ecological space from the service providing areas(SPAs)to the service beneficiary areas(SBAs)in a specific pathway under the influence of direct or indirect drivers." This concept focuses on the theoretical production of ecosystem services for the demand side rather than the actual well-being after spatio-temporal transmission,which can scientifically reflect the whole life cycle process of ecosystem services from natural ecological space output,then through spatial transmission,and finally consumed and enjoyed by humans.This will help us to further understand the mechanism and inner law of the effectiveness of ecosystem services across space and time.(2)According to the basic laws of physics,this paper treats ESFs transmission as a three-stage movement transformation process of "in situ stationary(Stage I)→potential movement trend state(Stage II)→ continuous stable spatial and temporal transfer process(Stage III)".Through modularization,this paper proposes the formation mechanism(three types of phenomenal support),driving mechanism(five kinds of driving factors)and operation mechanism(ten kinds of modular attributes)of ESFs.Based on the three mechanisms,the study innovatively proposes the analytical framework,the cognitive framework and the quantitative framework for revealing the whole mechanism system,which fully demonstrates the spatial logic and attributes of the whole life cycle process of ecosystem service flow conduction,and thus provides a certain integration,innovation and expansion of the existing theoretical foundation.(3)Based on the three-dimensional quantification framework of "state-motion-efficiency" obtained from ESFs transmission mechanism,this paper combines a series of spatial analysis and mapping techniques with ecosystem service modeling methods,and eventually selects Hangzhou as the case to carry out a multi-dimensional and multi-scale ESFs quantification and simulation.The results show that:(1)The urbanization activities of Hangzhou(the population keeps gathering from rural into urban,areas and the impervious surface gradual spread from urban into rural areas in the last three decades have exacerbated the imbalance between supply and demand of ecosystem services along the urban-rural gradient,increasing the "gradient potential difference" in ecosystem services between rural and urban/semi-urban areas in the "state dimension".(2)The differences in the properties of supply and demand states of units(nodes)and service transmission paths(edges)lead to different spatial trajectories of service flows in different types of ecosystems,which affect the "motion dimension" of service flows through network structural features,critical/sparse nodes and functional groups(service clusters).(3)Differences in the types and mechanism of ESFs determine that they have different "efficiency dimension" characteristics,which can be categorized and managed in various modes based on quantitative simulation results.(4)The concept of ESFs have great potential for enabling the construction of ecological civilization and high-level spatial governance,and can help promote the governance method from the existing "static ecological spatial governance" to "ecological service process governance" in the coming future.Through the institutional system of "institutional environment-policy tools-resource utilization",it can be found that the decision-making behavior of local governments in ecological service process governance is constrained by the incentive structure and basic system of the central government,and can be achieved through regulatory tools,planning tools,market tools,and incentive tools.The results of the policy instruments can directly influence the production,process and transformation efficiency of ecosystem services,and indirectly influence the institutional design arrangement in the process through feedback.