Simulating Analysis On The Suitable Environment Of The Endemic Pinaceae Plants In Qinling-Daba Mountains Areas

In recent years,the problem of endemic and precious plant resources endangered has become one of the hot issues.Based on the GARP and Maxent model,this paper analyzed the factors influencing the survival environment of endemic Picea neoveitchii,Abies chensiensis and Larix chinensis,which are the endemic pinaceae plants in Qinling-Daba Mountains areas,simulated the suitable distribution characteristics of the three pinaceae plant,and conducted the accuracy test of the simulation results are credible.The main conclusions of the study are as follows:(1)Using the Jackknife method to determine that the main factor influencing the spatial distribution of the three endemic pinaceae plants of Picea neoveitchii,Abies chensiensis and Larix chinensis is sea-level elevation.The suitable altitude of Picea neoveitchii is 1459-2277m,the suitable altitude of Abies chensiensisis 1670-2162m,and the suitable altitude of Larix chinensis is 2765-3928m.The secondary factors influencing the spatial distribution of three endemic pinaceae plants are:1)Picea neoveitchii,the average annual rainfall,the average annual rainfall of July,average temperaturein January,pH value,slope and soil organic matter content;2)Abies chensiensis,the extreme maximum temperature,annual extreme lowest temperature,annual sunshine hours,the average annual rainfall in July,5?or higher accumulated temperature,10? or higher number of days;3)Larix chinensis,annual extreme minimum temperature,annual relative humidity,average temperature in January,annual average rainfall,annual sunshine hours.(2)Based on the expert experience method,the suitability simulation results in the study area are divided into:high suitability,medium suitability,low suitability and inappropriateness.High and middle adaptation areas are the core adaptation areas of the three plants,The low and unsuitable areas are the unsuitable areas for plants 1)the core suitable range of Picea neoveitchii for the southeast of Gansu province within the study area,central of Shaanxi province,in central Henan province,in western Hubei province and central,northern of Chongqing city and Sichuan province,Core fitness area accounted for 2.549%;2)the core suitable range of Abies chensiensis for the eastern of Gansu province within the study area,in central Shaanxi province and southern,in central Henan province,in central and western Hubei province,the northern of the Chongqing city and Sichuan province,Core fitness area accounts for 20.652%.3)the core suitable range of Larix chinensis for eastern and southeast Taibai county Shaanxi province within the study area,Southern Mei county,Southwest of Zhouzhi county,south of Hu county and Changan county,North of Ningshan county,the surrounding area of Diebu county,Gansu province,northwest of Shennongjia,Hubei province,and the suitable area accounts for 0.641%.(3)The applicability test of the model simulation results was carried out according to ROC curve,and test results showed that AUC values of Picea neoveitchii,Abies chensiensis,Larix chinensis were 0.981,0.945 and 0.994 respectively,It shows that the simulation results have high reliability.