Research On Ecological Network Stability Based On Ecosystem Service Function And Ecological Ensitivity

As the urbanization process continues to accelerate,natural disasters occur frequently,industrial pollution intensifies,urban construction land expands disorderly,accelerates the fragmentation of habitat patches,blocks ecological corridors,accelerates the disappearance of biological habitats,and ultimately leads to ecosystem function weakened,and the ecological and environmental problems are outstanding.The reduction of biodiversity affects the stability of ecosystems and is not conducive to the healthy and sustainable development of regional socioeconomics.China’s ecological civilization construction has raised higher requirements for the protection of the ecological environment.With the development of landscape ecology,geography and other disciplines,the ecological environment in the new period has changed,new ecological protection methods and ecological protection concepts have emerged.The construction of an ecological network provides a theoretical basis and technical support for the preparation and implementation of an ecological protection plan,an analysis of the stability of the ecological network,and a reference basis for the subsequent smooth development of ecological protection work.This study is based on landscape ecology theory,and complex ecological network theory.It is based on landscape pattern analysis method,ecosystem service function importance evaluation method,ecological environment sensitivity evaluation method,ecological network construction method,and network stability analysis method.As a guide,analyze and evaluate the ecological environment of Xinfeng county,with the help of Arc GIS software landscape pattern index calculation software Fragstats4.2,the land landscape pattern of Xinfeng county was analyzed in 2009,2013 and 2017respectively.Identify the ecological source through the evaluation of the importance of ecosystem service functions and the sensitivity of the ecological environment,and build a composite landscape resistance surface through comprehensive evaluation of land use types,slopes,elevations and vegetation cover factors,which more truly reflects the regional ecological characteristics and processes.During the construction of the ecological network,the minimum cumulative resistance surface is constructed based on the minimum cumulative resistance model,and the potential ecological corridor is identified using the least cost path model.Pajek network analysis software is used to evaluate the comprehensive importance of the nodes of the network.The stability characteristics of the ecological network are analyzed by studying the changes of robustness indicators under external interference scenarios,and the importance of the ecological corridor is determined based on the gravity model.Finally,according to the stability characteristics of the ecological network in Xinfeng county,a corresponding network protection strategy is proposed.The results show that:(1)From 2009 to 2017,the landscape fragmentation of Xinfeng county showed an upward trend,and the overall quality of the ecological environment showed a downward trend.Although the landscape diversity increased,the magnitude was not large.(2)Based on the ecosystem service function theory,comprehensively identify the ecological source area through the assessment of the importance of ecosystem service functions and the evaluation of the sensitivity of the ecological environment.The total area is 486.49km~2,accounting for 16.97%of the total area of the research area,mainly distributed in the research area.In the eastern,southern and western parts of the district,the main land landscape type of the area is forest land,which conforms to the topographic features of Xinfeng county.(3)Based on the principle of landscape ecology,in the traditional method of using land use as a single landscape resistance surface,slope factors,elevation factors,and vegetation coverage factors are also added,and a comprehensive resistance surface is obtained through comprehensive evaluation.(4)Based on the complex network theory,the topological network extraction of the landscape ecological network in Xinfeng county generated a total of 126 nodes and 177 connecting lines.The nodes with high comprehensive importance play a key role in maintaining the stability of the ecological network;when the node failure rate reaches 80%The ecological network begins to paralyze;the important ecological corridor is conducive to promoting the circulation between species,and plays an important role in maintaining the overall stability of the ecological network and the normal function of the ecological function.(5)Based on the actual ecological situation of Xinfeng county,according to different protection purposes,three levels of protection management strategies were proposed,including node comprehensive importance,ecological corridor importance,and spatial differentiation management,to provide relevant suggestions for the formulation of ecological environmental protection strategies in the study area.