Spatial Distribution Pattern And Suitable Habitat Prediction Of Rusa Unicolor And Budorcas Taxicolor In Anzihe Reserve,Sichuan Province

To explore the mechanism of species distribution changing with climate change is of great significance for maintaining ecosystem’s functional integrity and protecting biodiversity.Rusa unicolor and Budorcas taxicolor are the national key protected wild animals in China.They are also the important parts of the ungulates with high ecological value and conservation value in the forest ecosystem in the southwest of China.In this paper,the information based on the entity,traces,feces of Rusa unicolor and Budorcas taxicolor were collected with the infrared cameras and line transect method in the protected areas of Anzihe in Sichuan Province.Combining the environmental variable information of climate,topography,vegetation and disturbance,we use the maximum entropy model(Max Ent)to evaluate the habitat suitability and analyze the spatial distribution patterns and seasonal change of habitat.The purpose of this article is to reveal the overlapping relationship of habitat and explore the coexistence mechanism of the sympatric distribution of Rusa unicolor and Budorcas taxicolor.The main conclusions are as follows:(1)Rusa unicolor are mainly concentrated in the central and southern areas of the Anzihe protected areas in Sichuan Province,preferring to perch in the altitude of 1800-3000 m;Budorcas taxicolor are mainly concentrated in the central and western areas of the Anzihe protected areas in Sichuan Province,preferring to perch in the altitude of 2200-3400 m.There are four high-density distribution areas of Rusa unicolor: Shaoyaogou,Niujinghe,Fangniuping and Dawowo,followed by Heidang,Hongshuihe and Jixinbao;there are two high-density distribution areas of Budorcas taxicolor in the protected areas: Shaoyaogou and Heidang,followed by Hongshuihe,Denggangping and Niujinghe.The vertical distribution patterns of them showed a mid-peak pattern with the trend of first increasing and then decreasing along the altitude gradient.(2)The suitable habitat area of Rusa unicolor in the Anzihe protected areas in Sichuan Province is 943.23 hm~2,accounting for 6.25% of the total area of the protected areas;the relatively suitable habitat area is 3390.15 hm~2,accounting for 22.48% of the total area;while the suitable habitat is less.The suitable habitat area in winter and spring is 993.22 hm~2,accounting for 6.59% of the total area of the protected areas,while that in summer and autumn is 2328.03 hm~2,accounting for 15.44% of the total area of the protected areas.The suitable habitat of Rusa unicolor varies with seasonal change.The suitable habitats are mainly distributed in the shrubs and deciduous broad-leaved forest at the mouth of Shaoyaogou and Niujinghe as well as distributed in the shrub and deciduous broad-leaved forest under the Dawowo and Longdenggou.(3)The suitable habitat area of Budorcas taxicolor in Anzihe protected areas in Sichuan Province is 1808.37 hm~2,accounting for 11.99% of the total area of the protection areas,and the relatively suitable habitat area is 8384.35 hm~2,accounting for 55.59% of the total area.The valley and both sides are suitable habitats for Budorcas taxicolor.In winter and spring,the suitable habitat area is 1653.63 hm~2,accounting for 10.96% of the total area of the protected area;in summer and autumn,the suitable habitat area is 2022.42 hm~2,accounting for 13.41% of the total area of the protected area.The suitable habitat of Budorcas taxicolor varies with seasonal change.The valley and its two sides are the most important suitable habitats.(4)The overlapping of suitable habitat area for Rusa unicolor and Budorcas taxicolor was 261.10 hm~2,mainly concentrated in the low mountain and valley areas in the middle and south of the protected areas.The main reason for the habitat overlap may be the similar demands for food resources of the two species,especially in the time of food shortage in winter and spring.The habitat selection and utilization of ungulates in the same area were influenced by resource acquisition,predation risk,inter-species competition and human disturbance,which results in their similarity and difference in habitat selection and utilization.Both Rusa unicolor and Budorcas taxicolor prefer a habitat area closer to the water source area with appropriate temperature and flat terrain.At the same time,they have diverse choices in vegetation types,elevation and other environment factors,and these differences might be one of the reasons leading them to adapt to each other for long-term coexistence.(5)There are obvious seasonal distribution differences in habitats of Rusa unicolor and Budorcas taxicolor in different seasons.In winter and spring,both of them live in the low altitude forest.In summer and autumn,Budorcas taxicolor moves to the high altitude area,while the distribution of the Rusa unicolor is relatively scattered.The suitable habitats of them partly overlap in temporal and spatial distribution,but in the long-term evolution process,in order to obtain the maximum generalized suitability,they have partial differentiation in spatial niche,temporal niche and habitat utilization mode,so as to achieve mutual adaptation and long-term coexistence.Based on the conclusion of this study,it is suggested that the management department of the reserve should strengthen the control of the ravines and their entrances to prevent human and animal from entering the ravines,strengthen the patrol and monitoring of Jiguanshan Forest Park and community collective forest in winter and spring,strengthen the monitoring and management of suitable habitats for Rusa unicolor and Budorcas taxicolor,and expand the area of Anzihe protected areas in Sichuan Province.