The Research On The Geographical Distribution Patterns Of Invasive Alien Plants In China

Alien plant invasion has seriously threatened global biodiversity and caused enormous damage to the structure and function of ecosystems in invasion areas.China is particularly vulnerable to the alien plants invasion and has become one of the countries most significantly affected by invasive alien species(IAPs)due to its widely territory,complex topography and diverse climatic conditions,.Therefore,it is of great significance to conduct researchs on theinvestigation,distribution patterns,invasion mechanism and risk assessment for the management,prevention and control,monitoring and early warning of IAPs.Based on the data collected from literature,books and field investigation,this study preliminarily counted 453 IAPs in China,belonging to 63 families and 261 genera,and then constructed a geographic distribution database that including 107 000 detailed latitude and longitude coordinates of IAPs.The nuclear ribosomal internal transcribed spacer(ITS)and chloroplast gene sequence(matK,rbcL,psbA-trnH)of IAPs were obtained to reconstructed the phylogenetic tree of IAPs.Then,we analyzed the geographical distribution patterns and invasion hotspots of species richness,weighted endemism,phylogenetic diversity and phylogenetic endemism of IAPs in China.In addition,we also analyzd the bioclimatic and socioeconomic factors affecting the geographic distribution patterns of IAPs in China using multiple linear regression.Finally,the potential distribution areas of 368 IAPs with distribution points more than 5 were predicted under current and future climate change scenarios using species distribution models.The results are as follows:(1)IAPs are mainly concentrated in Asteraceae,Fabaceae,Poaceae,Amaranthaceae,Solanaceae,Euphorbiaceae,Convolvulaceae,Brassicaceae,Onagraceae,Plantaginaceae at the family level,accounting for 69.09%IAPs in China.And as for the genus level,it mainly concentrated in Amaranthus,Euphorbia,Solanum,Ipomoea,Senna,Oenothera,Acacia,Erigeron,Crotalaria,Lolium and so on.(2)The diversity of IAPs in China decreased from the southeast coastal area to the northwest inland area.The regions with the most diversity were mainly distributed in the south and southeast coastal areas of China,followed by the southwest and the provincial capitals and their surrounding areas.The hotspots for the priority management of IAPs are mainly concentrated in the southeast and south of China,and a few hotspots are distributed in Tibet,Xinjiang and Northeast China.(3)The driving factors of species richness and phylogenetic diversity distribution patterns of IAPs in China showed that the temperature-related factors had the most significant influence.In addition to the environmental factors and socio-economic factors,the distribution patterns of the phylogenetic endemism and weighted endemism of IAPs are also affected by elevation and traffic.Population(POP),gross domestic product(GDP),isothermality(BIO3),mean temperature of wettest quarter(BIO8),and annual precipitation(BIO12)all affected the diversity distribution patterns of IAPs in China.(4)The potential distribution areas of most IAPs(71.47%[RCP2.6],57.34%[RCP8.5])will increase under future climate change,including the areas with high elevation.The south and southeast of China are predicted to have high species richness of IAPs.Under future climate change scenario,the areas in eastern Sichuan and western Chongqing with high species richness showed significant increases,and under the RCP8.5 climate change scenario,the invasion risk in northern Tibet,western Qinghai and southern Xinjiang in western China would increase.Under the current and future climate change scenarios,the invasion hotspots of IAPs are mainly located in the east of China’s 800mm iso-precipitation line,but under the future climate change scenario,the invasion hotspots will further expand to inland areas.(5)Under the future climate change scenario,most regions in China are facing the risk of increased species richness,especially inland areas,while the areas with decreased species richness are distributed in parts of southern and northern China.The centroid of potential distribution areas of IAPs indicated that most IAPs(92.66%)would shift to the northwest,and only 27 species would migrate to the south under RCP2.6 climate change scenario.Based on the most complete IAPs list in China,this study obtained accurate geographic distribution data of IAPs for the first time to analyze the geographic distribution patterns and its influencing factors by using fine grid cells,then identified the priority management hotspots of IAPs in China.Finally,the distribution dynamics of IAPs under future climate change scenarios were predicted.The results of this study can provide an effective reference for the spatial management and the early warning and rapid response of of IAPs in China in the future.