Effects Of Climate Change On Geographical Distribution And Prediction Of Migratory Birds In China

Billions of migrating animals migrate every year to seek more foraging opportunities and improve their reproductive success.During migratory process,these migratory species transport nutrients,energy,and other organisms(including seeds,parasites,and pathogens)between different sites.Migratory species also forage and are preyed on the journey,thus establishing transport and nutrient flow relationships with local ecosystems,while bird migration is the largest species migration movement in the world.Migratory birds are vulnerable to external influences,especially climate change,throughout the migration process.Therefore,this study combined migratory bird sample data and China national-scale climate environment data to construct species distribution models(SDMs)of different species and assess the spatial correlation between climate environment variables and migratory bird distribution,and predict bird distribution under future climate scenarios(RCP2.6 and RCP8.5).Firstly,this study used Max Ent model combined with sample data and Worldclim climate data on the Birdreport for potential geographical distribution simulation at the national scale in China,and used GIS to draw binary distribution maps to determine the habitat.At the same time,the spatial correlation and dependence between climate environment variables and bird distribution were evaluated.Results show that the area of habitat assessed by the Max Ent model accounting for 16.43% of the total land area in China,mainly distributed in the plain area of southeast china,including the middle and lower reaches of the Yangtze River Plain and the North China Plain.Secondly,based on the future climate scenarios,this study predicts the distribution of birds in the future,and compares with the present situation to determine the increase or decrease of the habitat and the migration of birds.The results show that the habitat of migratory birds will shrink to the population centroid in the future scenarios,and the area will decrease.At the same time,it will show fragmentation,the distance between the habitat will become longer,and the flight obstruction of birds between different habitat will increase.Finally,based on the current situation analysis,the hot spots of migratory bird distribution(3 different climatic regions,6 watersheds and the middle and lower Yangtze River)were modeled and analyzed to compare the adaptation regional changes in different regions and determine the constraints variables of each region.There are also effective suggestions based on the comparison between the potential geographical distribution of migratory birds and the location of nature reserves.The results show that NDVI and LUCC play a important role in the distribution of birds in central and southern China and have irreplaceable effects.There are differences between the China's nature reserves and the distribution of birds,and the protection of birds needs to establish a complete framework.