| Asian elephant is one of the level?key protected wildlife in our country.Although the population is growing steadily in recent years,due to habitat loss and fragmentation,the species is still under serious threat.In this paper,the main research area is within 1km on both sides of the proposed Simao-Jiangcheng expressway.By using methods such as interview survey,trace track survey,UAV(unmanned aerial vehicle)survey and quadrat survey,the number,distribution,movement corridors and habitat status of Asian elephants along the proposed Simao-Jiangcheng expressway were investigated.After using ArcGIS superposition analysis,the results showed that,some of the routes highly overlap with the corridors of Asian elephants.According to these results,the proposed expressway is most likely to block the original corridors of Asian elephants in this region,and the risk of traffic accidents between elephants and vehicles may be very high when elephants cross the highway.The main results and conclusions are as follows:(1)A total of 46 Asian elephants were recorded in Simao District,Jiangcheng County,Pu'er City,all belong to Xishuangbanna-Pu'er Asian elephant population,involving Pu'er-Jiangcheng sub-population.Pu'er-Jiangcheng subpopulation can be divided roughly into three groups as a group total of 46,Mankelao is a group of 12,Dashujiao is a group of 22 and Huashiban is a group of 11.(2)Based on basic geographic data and remote sensing(RS)data,by using ArcGIS software,taking the main habitat factors affecting the distribution of Asian elephants as suitability evaluation parameters,three environmental factors including altitude,slope and vegetation cover were selected.Analysis of single-factor suitability data for Asian elephant habitats along the proposed high-speed,and then,these three environmental factors are superimposed and analyzed to obtain comprehensive suitability data for habitats so that the suitability for Asian elephants along the line is comprehensively evaluated.The results show that,the suitable habitat of wild Asian elephants is fragmented,this area is not the most suitable area for Asian elephants to survive.(3)Ten plant samples were set up along the proposed route,result show that the natural vegetation in the study area is mainly monsoon evergreen broad-leaved forest and thermal shrub,and the artificial vegetation is mainly artificial forest,especially the tea plantation.A total of 149 plants were recorded,belongs to 31 orders,59 families,and121 genera.A total of 62 species of Asian elephant feeding plants were recorded,including 14 species of cultivated crops and 48 species of wild plants,belonging to 42 genera,29 families and 19 orders,accounting for 32.2% of the total number of wild plant species.(4)Using ArcGIS10.2 hydrological analysis to extract the water network of study area,then add road map of the proposed Simao-Jiangcheng highway and nearby Asian elephants' track,superposition analysis found that the proposed Simao-Jiangcheng highway Kangping to Zhengdong period overlap with the water distribution and Asian elephants' route.So the construction of highway may to a certain degree effect Asian elephants' use of water.Eleven saltpetro ponds were investigated near the section from Kangping to Zhengdong of the proposed Simao-Jiangcheng expressway.Install infrared camera and analysis minerals of nitrate pond samples,we found that Asian elephants prefer nitrate pond in evergreen broad-leaved forest,and of high content of sodium.In addition,other animals also use nitrate pond.The nitrate ponds mainly used by Asian elephants are far away from the expressway,so direct damage the proposed expressway will have on Asian elephants using nitrate ponds is little.(5)Trace tracking method is used for local Asian elephants' migration path tracking.And the movement track and main passage of the Asian elephants were plotted.Combined with the route design of the expressway project,it is found that there are a total of 13 sections on Line K which are directly related to Asian elephants.These sections have been used as passageways by Asian elephants and are the main sections where Asian elephants may cross the expressway.Therefor we draw a conclusion that the proposed Simao-Jiangcheng expressway will be a barrier to the Asian elephant population that moves around it.(6)In the distribution area of Asian elephants,places where the elevation is below1,300 m and there are crops they like to eat are the areas Asian elephants like.When the designed route of expressway is to cross these areas,it may form a blocking effect on Asian elephants.Through this study,it is hoped that it can provide useful reference for the site selection and design of wildlife passage,effectively alleviate the impact of highway construction on wildlife,and promote the coordinated development of wildlife protection and highway construction. |
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