Study On The Ecological Suitability Of Mongolian Leek In Bayannur City Based On MaxEnt Model

Desert vegetation is a kind of zonal vegetation in arid area,which has unique functional characters and is an important plant resource in desert area.Allium mongolicum is a typical zonal plant endemic to desert area,and it can form plant patches in desert ecosystem.The study on the geospatial distribution of the Allium mongolicum and its response to climate change will provide important theoretical and technical support for the study of desert vegetation restoration and reconstruction,biodiversity conservation,and ecosystem stability.In this study,Arc GIS software and Max Ent model were used to analyze the suitable distribution area of Allium mongolicum in Bayan Nur region and its response to climate change.Forty-nine distribution points of Allium mongolicum in Bayan Nur City were obtained through field measurement and site investigation and screening.The spatial distribution variable dataset and environmental variable dataset of Allium mongolicum were established and input model was used for training.The Max Ent model was used to evaluate the displacement importance values and contribution rates of 23 environmental factors,and the six environmental factors that played a major role in the distribution of the Allium mongolicum were selected by the knife cutting method,and the response curves of the six environmental factors were calculated.The geographical spatial distribution pattern of Allium mongolicum was predicted under the current climate conditions(In1960-1990)and the future climate scenarios(RCP2.6,RCP4.5 and RCP8.5 in2050 and 2070).The main research results are as follows:1.The simulation results of Max Ent model show that the AUC value under the ROC curve under the current climate and the future climate is greater than 0.80,indicating that the prediction of the model is highly reliable.2.The main environmental factors affecting the distribution of A.Allium mongolicum were surface temperature,daily range of mean temperature,isotherm,slope,seasonal variation of temperature and soil moisture.3.Under the current climate,the high suitable area of Allium mongolicum accounted for 19.7%of the total area of Bayan Nur(64,000 km~2),and the medium suitable area and low suitable area accounted for 12.9%and17%of the total area studied.4.Compared with the current distribution,under three climate change scenarios:A)the area of the high adaptation zone will decrease by 1.8%,1.1%and 0.9%by 2050,respectively,from the current distribution;4 percent,1.8percent and 2 percent by 2070;B)The area of the medium suitable area will increase by 3.6%,2.7%and 1.9%by 2050,respectively;By 5.5%,3.4%and4.4%,respectively,by 2070;C)Low suitable areas will be increased by 5.7%,5.4%and 0.06%by 2050,respectively;By 4.5%,6.5%and 0.8%by 2070;D)Reducing the area of unsuitable areas by 7.5%,6.8%and 0.9%by 2050,respectively;By 5.9%,8%and 3.2%,respectively,by 2070.The geographical spatial distribution of Allium mongolicum was mainly affected by environmental factors such as surface temperature,daily range of mean temperature,isotherm,slope,seasonal variation of temperature and soil moisture.With climate change,the distribution pattern of Allium mongolicum has changed in Bayan Nur City,so it is very important to strengthen the protection and reasonable cultivation of Allium mongolicum.