Geographical Distribution And Suitability Cultivation Area Of Five Typical Ecological Tree Species On The Qinghai-tibet Plateau

The Qinghai-Tibet Plateau,an important ecological barrier in the whole East Asia,is faced with the conflict between the fragile ecological environment and human activities,So,the protection and restoration of vegetation has become the focus of the construction of the Qinghai-Tibet Plateau.With the general trend of global warming,the Qinghai-Tibet Plateau,as a sensitive area of climate change,is under increasing environmental pressure,and ecological environment restoration is the key area that needs to be paid attention to.In order to ensure the durability of the ecological recovery,climate change under the background of typical ecological species need to be clarified with the range of change,to simulate the current and future climate situations suitable for different species distribution area,its range and direction,of the qinghai-tibet plateau areas should be to address climate change,decided to planning strategy has important significance On the basis of field investigation,we chose to Populus szechuanica var.tibetica,Salix paraplesia var.subintegra,Hippophae rhamnoides,Juglans regia,Amygdalus mira as the research object.The samples,coordinate data and the selected environmental data were brought into the Maxent to predict the suitable distribution areas of these species,and the results were imported into Arc GIS for visual analysis.The suitable distribution areas,with the current climatic conditions RCP4.5 and RCP8.5 in 2070 s,of these 5species were simulated,and the following conclusions were drawn:1.In field investigation,Populus szechuanica is mainly distributed in the Yar Lunzangbo River basin and its tributaries,acrossing Shannan,Lhasa and Nyingchi.There are a lot century-old Salix paraplesia in the Tibetan Gardens of Xigaze,Shanan and Lhasa.In the suburbs of Xigaze and Shannan,there are hundreds of Hippophae rhamnoides forests in the suburban district.Juglans regia,in the southeastern region of the Qinghai-Tibet Plateau are distributed in villages,many ancient trees,a tree is a species.Amygdalus mira distribution center is Nyingchi Valley,the Nyingchi City and Bomi county,with ancient trees distributed in patches.2.With the analysis of the Max Ent,the conclusions are drawn:(1)In the current climate conditions,the widest suitable distribution of Hippophae rhamnoides has stretch across southern Tibet of the Qinghai-Tibet Plateau and the marginal area of the Qinghai-Tibet Plateau,from the first step to the second step(The three steps of China’s terrain).Populus szechuanica and Juglans regia have similar suitable distribution areas,including Brahmaputra drainage basin,and its surrounding valleys,Nu Chiang(salween),Lancang River(Mekong River in china),Jinsha River,Yalong River and part of Minjiang River basin.Taking the southern section of the Brahmaputra drainage basin as the center,the core suitable distribution area of Populus szechuanica was shifted upstream,while Salix paraplesia was shifted downstream.(2)The controlling factors,affecting the suitable area,of Populus szechuanica distribution include BIO06,BIO15,BIO13.Salix paraplesia,Bio03,Bio15,Bio06,Bio18.Hippophae rhamnoides,Bio06,Bio04,Bio19.Juglans regia,Bio06,Bio15,Bio11,Phikcl.Amygdalus mira,Bio06,Phikcl.(3)Hengduan Mountains,centered on the Nujiang River,Lancang River valleys and Jinsha River valleys,are the ecological shelters for these five plants.With the RCP4.5 and RCP7.5 climate scenarios in 2070,the suitable distribution areas of Populus szechuanica,Salix paraplesia and Hippophae rhamnoides,all contracted,while the suitable distribution areas of Juglans regia and Amygdalus mira expanded towards Hengduan Mountains.(4)The most suitable forest area for all species is concentrated in the Yarlung Zangbo River basin.Especially in the south of Yajiang Mountain and Nyingchi section,the afforestation area is the most stable.The afforestation area of walnut and levus willow can be extended to the valley area of Hengduan Mountains.