Modeling Of Landscape Connectivity And Ecological Corridor In Southern Fujian Region Under Climate Change

Global climate change and human activities are the two main drivers in the evolution of landscape pattern changes,landscape fragmentation caused by human activities and the impact of climate change on habitats lead to sevious changes to species habitat,distribution and diversity.The study of landscape connectivity and landscape corridor simulation has become a key topic in landscape ecology research.Landscape connectivity measures the organic connection based on habitat function and ecological processes.Exploring the mechanism of climate change and human activities on landscape connectivity is of great significance for mitigating its adverse effects and related research on species migration and ecological flow.This study focus on the landscape connectivity in southern Fujian region(Xiamen,Zhangzhou and Quanzhou).Firstly,I analyzes the temporal and spatial dynamics of human activities through literature search and natural attribute assignment.Secondly,this research draws on hydrological analysis to innovate the landscape connection under the influence of climate change.The method of degree evaluation is used to quantitatively evaluate the spatial and temporal distribution of landscape connectivity under the climate change in the Delta region.Based on the results of landscape connectivity,the potential species migration corridors with climate factors tending downward are simulated,and bottlenecks are identified.The bottleneck point and the warning point.The main research contents and conclusions of this paper are as follows:(1)The spatial and temporal dynamic evolution of human influence in southern Fujian region.Based on the human activity intensity of land use and cover in the study area,land use and cover types are divided into three categories including natural,semi?natural and non-natural land.According to the natural attribute of landscape types and their values in related research,different types of human activity are assigned scores to evaluate the impact of human influences on landscape pattern,ecological structure and function in southern Fujian region from 2000 to 2015.The results show that a series of changes in human activities have taken place in recent years,construction land expansion,natural land fragmentation,the traffic infrastructure development,and rapid population agglomeration,have great impacts on the ecological system.The distribution of human influences shows a decreasing trend from east to west,coast to inland,ranging from high to low as Xiamen,Zhangzhou,Quanzhou.And human influences rises over time,high human influence expansion and low human influence fragmentation,of which the most significant change in zhangzhou.(2)Simulation of landscape connectivity under climate change.Drawing on hydrological analysis in ArcGIS,this study innovates the landscape connectivity evaluation model of climatic factor gradient("high temperature"to" low temperature","high precipitation"to"low precipitation"and"low precipitation"to"high precipitation").This reseach estimate the landscape connectivity of the Fujian triangle region under the stress of climate change and human activities.Highest temperture connectivity is mainly distributed in the border southwest of Quanzhou and Zhangzhou,west and south area of Zhangzhou,and other areas is covered with high heterogeneity,complex climatic conditions and low population density.The forest is the land use type with high connection degree.Because of higher human development intensity and population density,the natural semi natural patch in plain and coastal areas shows high fragmentation and there was no effective connection between adjacent patches.During 2000-2015,the landscape connectivity of temperature gradients decreased slightly in Southern Fujian region,but increased greatly when the landscape type of natural attribute changed to semi-natural attribute.The distribution trend of precipitation connectivity is similar to that of temperature,which shows that the inland area is high connectivity while the coastal area is low,and the high connectivity area is mostly located in the larger natural semi-natural patch,but there is a clear precipitation gradient path within the patch.The change of connectivity showed a tendency of aggregation.When precipitation increased,it converged to the edge of patch,and the decrease of precipitation flowed to the center of patch.(3)Elastic simulation of temperature gradient path and landscape connectivity.Based on the evaluation results of temperature landscape connectivity,the species migration corridor of the temperature gradient path is constructed,and the intersection of the corridors is identified.The human impact is used as an indicator to verify the bottlenecks and warning points of the corridors that affect the efficiency of the corridor.There are nearly two-thirds of the triangular ecological corridors and ecological nodes in Zhangzhou.The ecological corridors connecting the high-temperature and low-temperature areas are concentrated in the mountainous areas with large climate differences,and the ecological corridors are also long,while sparse and short corridors in coastal urban areas.90%of the tipping point are located in semi-naturally woodlands,supporting most habitats and species migration,and 87%in high population density areas,limiting their connections.The early warning points are mostly distributed in the high connectivity area,and the natural environment of some important ecological nodes is destroyed,and its ecological connection is weakening.(4)Climate landscape connectivity evaluation and ecological corridor construction tools.Based on the innovative assessment method of climate landscape connectivity,a custom tool of ArcGIS platform is designed and developed.Through data input,resistance layer superposition,classification of climate factors,determination of climate direction and calculation of cumulative resistance direction,Ecological corridor extraction.This paper mainly has the following innovations.(1)We improved the method of landscape connectivity evaluation under climate change,completed modeling of climate landscape connectivity in Southern Fujian region and development of ArcGIS custom tool based on this model.(2)In the simulation of temperature gradient landscape connectivity,the study of tipping point and early warning point is extended,and as the key nodes affecting the landscape connectivity of the Fujian Triangle region.And(3)the landscape connectivity of precipitation gradient in Southern Fujian region is preliminarily explored,and the research on landscape connectivity under climate change(temperature and precipitation)is improved.