Study On The Resilience Of Land Ecosystem In Mining Area And Its Measurement And Regulation

No matter the land in during-mining area or in the reclaimed area,they usually face various disturbances.The sustainable use of these kinds of land is a practical challenge rising in the process of mined land reuse and ecological conservation in mining area.International academia of ecological restoration increasingly recognizes resilience as a key to sustainability of a system.However,in the context of land ecology in mining area,the connotation and essence of resilience are poorly studied.The measurement and regulation of resilience are also paid less attentions.The dissertation aims at introducing the resilience theory into the research field of land ecosystem in mining area.Main research objectives include clarifying the connotation and essence of resilience of land ecosystem in mining area,developing indices and methods for measuring resilience,as well as revealing the regulation mechanism of resilience.To this end,the dissertation firstly analyzed the essential characteristics of land ecosystem in mining area based on literature research and field investigation.Secondly,logical deduction and differential equation modeling were developed to clarify the connotation and essence of resilience of land ecosystem in mining area.Thirdly,indices and methods for measuring specified resilience and general resilience were developed through mathematical modeling.Fourthly,the regulation mechanism of resilience of land ecosystem in mining area was analyzed.Case studies in three different mining areas was then enclosed to validate and instantiate the resilience and its measurement and regulation methods.The main conclusions are listed as follows:1)The analysis on the characteristics of land ecosystem in mining area indicates that: land ecosystem in mining area has a diverse components and complex structure.Land in mining area not only could support the mining activities,but also can provide a certain ecosystem service such as supporting,provisioning,regulating,cultural service.The artificially induced mining activities and restoration engineering are the main disturbances suffered by land ecosystem in mining area.Apart from these,there are some other artificially or naturally induced disturbances such as land reuse and climate change.Under the driving forces of these disturbances,the comprehensive change patterns of land ecosystem in mining area include state persisting,degeneration to new state,restoration to new state,and recovery to original state.In face of disturbance,land ecosystem in mining area could show certain ability of self-sustaining.2)On the basis of the mental model and logical deduction,the dissertation defins the connotation of resilience of land ecosystem in mining area as the capacity of a land ecosystem to retain its state in the face of mining disturbance or other changes.In the context of land ecology in mining area,“resilience of what” is the land ecosystem;“resilience to what” is mining disturbance or other changes.The resilience of land ecosystem in mining area has three basic characteristics including materiality,quantity,and plasticity.This concept has its independence.The part of speech or description objects are different from other concepts such as self-recovery,recovery ability,restoration,self-sustaining ability,etc.3)Based on the established dynamic model(VWS_model)of land ecosystem in mining area,this dissertation identified and simulated the formation basis and process of resilience of land ecosystem under different scenarios including without disturbance,after mining disturbance,after restoration engineering disturbance,and random disturbance.The results show that: the system equilibrium solution and the qualitative structure have certain attractiveness and stability respectively due to that the land ecosystem is self-organizing and embedded in several internal feedbacks.As a result,the land ecosystem in mining area reflects resilience that enables system can absorb disturbance and retain its state.Thus,resilience could be considered as a dynamic property of land ecosystem in mining area.From the mathematical perspective,the size and shape of basin of attraction and parameters space are the key factors influencing the quantity of resilience of land ecosystem in mining area.The equilibrium solution,basin of attraction and parameters space are different across different scenarios,which indicates that the various disturbances have impacts on the land ecosystem in mining area and its resilience.4)According to different cognitive objective of disturbance,the measurement of resilience of land ecosystem in mining area could be conducted from two aspects including specified resilience and general resilience.Specified object,disturbance,parameter and parameters' threshold are keys for measuring specified resilience.The measurement of general resilience could be achieved by comprehensively measuring the six attributes including diversity,ecological change,modularity,tight feedbacks,ecosystem service and overlapping governance.Absolute Index of Specified Resilience(AISR)can indicate whether the system state can be persisted in face of specified disturbance or not.Relative Index of Specified Resilience(RISR)and Relative Index of General Resilience(RIGR)could indicate if the system's specified resilience and general resilience has reached the reference level.5)Resilience regulation is an important pathway to obtain the ecological sustainability of land in mining area.The theoretical analysis shows that the main methods to resilience regulation are to enhance or overcome resilience.The enhancement and overcoming of the specified resilience could be achieved mainly through the regulation of the specified parameters,the relationship between the parameter variables and the disturbance,and the threshold.The general resilience can be regulated by optimizing the basic attributes of general resilience of land ecosystem in mining area.The implementation of resilience regulation should adopt strategy of adaptive action.The action mainly includes three key procedures such as resilience monitoring,evaluation and regulation.In order to better realize these procedures,optimization measures such as expanding participation,encouraging learning,intensive research and aggressive innovation are needed.6)To apply and verify the resilience and its measurement and regulation methods,the dissertation conducted case studies in Buliangou underground mine,Curragh surface mine and Mengjiagou post-mining area.The main procedures for applying the resilience theory are issue identification,instantiation of resilience connotation,and resilience measurement and regulation methods analysis.These case studies indicate that different mining area may have different land ecological issue.The resilience theory can help managers to clarify the key of the persistence of system state.Based on results of resilience measurement and regulation method analysis,the condition and influence factors for persist the system state in face of disturbance can be well understood,so as to facilitate the sustainable management of land ecosystem in mining area.To achieve the ecological sustainability of land in mining area,it is necessary to establish the resilience thinking in the field of land ecology in mining area.Acknowledging resilience is helpful to understand the mechanism of mining area's land ecosystem to retain its state in face of disturbance,so as to provide the theoretical and practical basis for land reclamation and ecological restoration in mining area.