Study On The Planning Strategy Of Multi-scale Ecological Restoration In Ecotone At The Piedmont Of North Qinling Mountains

In the context of the construction of ecological civilization and implementation of green development,theories and methods of national spatial restoration are being improved,and ecological protection,restoration and management are being carried out extensively throughout the country.Since 2018,in order to restore the ecological health of the piedmont of north Qinling Mountains as soon as possible,a large number of ecological restoration projects have been put on the agenda.However,the types of ecological restoration projects are variable and complex,but the technical methods are simple,so the ecological restoration plan is difficult to implement and the effect is below expectation.The main reasons lie in two aspects.First,less attention has been paid to the landscape characteristics of the piedmont of north Qinling Mountains,and the restoration plan is not based on the characteristics of the interlacing of man and nature.Second,attention has been paid to the analysis of landscape pattern and ecological process at a single scale,less consideration has been given to the pertinence and systematicness of multi-scale ecological restoration strategies.From the perspective of landscape architecture,the core of this study is how to identify the key restoration areas and nodes of ecotone at the piedmont of north Qinling Mountains,so as to formulate a consistent ecological protection and restoration plan.The main objectives of this study are as follows.First,it analyzes the process and factors of ecological degradation in the piedmont of north Qinling Mountains from the perspective of ecotone.Second,it identifies the key restoration areas and nodes to achieve the connection of multi-scale ecological restoration plan.In this thesis,it mainly applies pattern-process-scale theory and relevant theories of ecotone and ecological restoration.The specific methods in this research are as follows.First,it uses general methods,such as literature research and field research methods.Second,it uses comprehensive methods,such as landscape health assessment models and ecological security pattern models in landscape ecology,Geodetector in geography,environmental assessment methods in environmental science,and Green Infrastructure and regeneration design in Landscape Architecture.According to the practical problem,the discipline question and research objectives of Huyi district at the piedmont of north Qinling Mountains,this study is mainly divided into four parts.In the first part,it introduces the natural environment and human society characteristics of ecotone at the piedmont of north Qinling Mountains.Through the analysis of the landscape structure characteristics of class-level and landscape-level by the landscape pattern index from 2000 to 2019,it analyzes the gradient changes of ecotone,and identifies the edgy area.In the second part,according to the characteristics of the natural and artificial composite ecosystem at the piedmont of north Qinling Mountains,a "pressure-state-response" model for landscape health assessment of ecotone is constructed,and the spatial distribution of ecological degradation is analyzed through landscape health assessment of Huyi district in 2000,2010 and 2019.In the third part,it analyzes the key factors of ecological degradation in the piedmont of north Qinling Mountains,estimates the spatial trend of ecological degradation,delimits the ecological restoration zones,identifies the important ecological sources,corridors and nodes,so as to determine the key restoration areas and nodes.In the fourth part,it proposes a multi-scale restoration strategy of ecotone at the pidmont of north Qinling Mountains in terms of ecological restoration zoning,Green Infrastructure and restoration of key nodes.According to the location of the demolished land,the landscape regeneration scheme is formulated based on the restoration objective and environmental assessment results.The research conclusions and innovations of this thesis are as follows.Firstly,it constructs the nested analysis framework of ecotone scale-edge scale-site scale.Previous studies have paid less attention to landscape characteristics of ecotone at the pidmont of north Qinling Mountains.In this study,it selects Huyi district as a typical unit in ecotone,delimits the area between 450 m and 1100 m above sea level as the edge area with sharp changes in environmental gradient,and selects the demolished land as the site unit for ecological restoration.Based on the ecotone theory,the pattern and process characteristics of the pidmont of north Qinling Mountains are analyzed,and a multi-scale analysis framework is constructed to identify key restoration areas and nodes.Secondly,it identifies key restoration areas and nodes of the piedmont of north Qinling Mountains by using the theory of pattern-process-scale.In terms of landscape pattern,human disturbance factors,blue-green spatial structure,natural and social responses are selected as landscape health assessment indicators according to landscape pattern index and ecotone characteristics.In terms of process,the root cause of ecological degradation is population growth,the landscape health can be improved by reducing artificial interference and adopting scientific restoration methods.According to the results of landscape health assessment,the spatial trend of ecological degradation is rapidly spreading from the artificial area to the edge area.In combination with the current land use and the range of the edge area,key restoration areas and nodes are identified.It identifies key ecological networks by analyzing biological migration process.It uses situational analysis of biological and hydrological processes to identify key restoration nodes.Thirdly,it connects ecological restoration planning and design by identifying key restoration areas and nodes.According to the key restoration areas,the artificial area,the edge area,the natural area are divided,and the ecological restoration strategies are formulated respectively.Based on the key ecological network,hydrological process and cultural recreation process,the Green Infrastructure Planning is formulated.According to the specific ecological problems of key restoration nodes,the ecological manners are given.It compares the demolished land with the multi-scale restoration strategy,sets the regeneration goal of each site,and formulates the landscape regeneration plan by comprehensively considering the soil fertility,plant growth,terrain and storm flood facilities of the site.