Habitat Quality Assessment And Potential Distribution Prediction Of Asian Elephant Based On 3S Technology

As an IUCN endangered species and a CITES Appendix I species,the Asian elephant is a flagship species that strongly relies on tropical forest ecosystems.It is mainly distributed in172 isolated areas in 13 countries in Asia.The habitat is narrow and the habitat quality is poor.protection.However,the current research on the habitat of Asian elephants mostly focuses on the regional scale,and the research content is relatively single,which makes it difficult to provide a basis for macro decision-making.Therefore,analyzing the current and future habitat conditions and changing trends of Asian elephants on a macro scale can provide a theoretical basis for formulating and planning Asian elephant habitat protection measures,and is of great significance to the protection of Asian elephants.This article uses 3S technology to deeply explore the factors of habitat loss,evaluate the habitat quality of Asian elephants from a macro scale,and establish a change prediction model,in order to provide theoretical and data support for the conservation and research of Asian elephants at the macro scale.The main work and results of the thesis are as follows:(1)Based on long time series land use data,the factors of Asian elephant habitat loss were analyzed,and the InVEST model was introduced to evaluate the habitat quality and scarcity of Asian elephants in the study area.The results of the study show that from 1992 to2015,the main factors for forest loss in the study area were the substantial expansion of urban residential land and agricultural land;the core area of the Asian elephant distribution was affected by linear infrastructure(such as road networks)and industrial facilities(such as mining).)And other development impacts,leading to an increase in the rate of loss and fragmentation of habitats in the core area.Cultivated land,construction land,and bare land are the main driving factors for the loss of Asian elephant habitat.From 1992 to 2015,the proportion of low-quality habitat areas in the study area increased by 0.8%,and the proportion of high-quality habitat areas decreased by 0.75%.The overall habitat quality was poor,and the area loss rate of high-quality habitat areas was about 4000 square kilometers per year;The habitat scarcity index in the study area(especially the core area)continues to rise,and the stability of the ecosystem is declining.It is urgent to take corresponding protection measures to alleviate the pressure on the survival of Asian elephants.(2)Through the screening of 759 Asian elephant distribution points and Spearman correlation analysis on 24 environmental data,194 Asian elephant distribution points and 11 environmental variables(Spearman<0.7)were obtained to participate in the establishment of the Maxent model.The results show that the accuracy of the training sample and the test sample reached 0.968 and 0.933,respectively,which proves that the model prediction results are highly accurate;the 6 main environmental variable factors provide the model with a92.4% contribution rate,of which the annual temperature contribution rate is 53.3% The high(4.44%)and medium(2.28%)suitable areas suitable for the survival of Asian elephants in the study area account for relatively few,and the high(30%)and medium(20%)suitable areas have a low utilization rate.(3)A potential ecological corridor for the habitat of Asian elephants was constructed through the analytic hierarchy process.Using expert models to combine the characteristics and selection rules of Asian elephant habitats,a comprehensive analysis of 14 main influencing factor layers including vegetation,society,geography,ecology and other factors;The relative weight value of each influencing factor is obtained by the analytic hierarchy process,and the comprehensive resistance value between the core areas of the Asian elephant distribution is obtained by using a weighted linear equation.The least cost path method is used to obtain the potential ecological corridors between the core habitats of Asian elephants,and 148 potential ecological corridors for Asian elephants are obtained through the corridor feasibility assessment,of which 21 are transnational ecological corridors,which are useful for expanding the living space of Asian elephants.Realistic guiding significance.(4)Four global climate models(BCC-CSM1-1,CCSM4,Had GEM2-ES,MRI-CGCM3)with different typical concentrations(RCP2.6,RCP4.5,RCP6.0,RCP8.5)were predicted using Maxent model Temporal and spatial trends of Asian elephant habitat in 2050 and 2070 under the scenario.The results show that the AUC values of the model prediction results are all greater than 0.94,indicating that the prediction results are highly accurate.Under various climate change scenarios,whether it is in 2050 or 2070,as the carbon concentration increases,the area of the Asian elephant's highly suitable area gradually shrinks,and the center of mass moves northward.All prediction results show that under the RCP8.5 scenario,Asian elephants will have a great risk of extinction.