Using Species Distribution Models To Predict The Potential Distribution Regions Of Adansonia In Madagascar

Madagascar,as one of the most important biodiversity hotspots in the world,has a high degree of species diversity and endemism.About 80% of the species belong to endemism,among which baobabs is the most typical one.In recent years,due to the expansion of population and the increasing demand for land,Madagascar’s biodiversity habitat has been seriously damaged,and global climate change has also increased the risk of regional species loss.Adansonia L.belongs to the Bombacoideae of Malvaceae.There are 8 species in the world,6 of which are endemic to Madagascar.The purpose of this study is to explore the impact of climate change on baobabs in Madagascar.By collecting the detailed distribution location and longitude and latitude of six baobabs in Madagascar,the potential niche of each baobab was simulated by using species distribution simulation,and the change of potential distribution area of baobab species in Madagascar in present,2050 and 2070 under the influence of climate change was studied.Through the comparison of distribution and regional changes of baobabs,the protection of baobab trees in the future was discussed.We had got the following results:1.It was found that all baobab trees showed changes in distribution area and area.Under the climate change,the distribution area of A.fony and A.suarezensis will have a considerable increase in the future,and the distribution area of A.grandidieri,A.madagascariensis,A.perrieri,A.za will decrease gradually in the future.2.All species show a serious loss of current habitat,the most serious of which is A.fony species which ironically seem to increase in other area away from the current distribution areas.The comparisons of results for current distribution and result for future predictions revealed range shift both in size and direction with a bias towards the eastern and southern side.However,the distribution range changes for some species remained constricted,probably due to current dispersal limitations.3.Among the six baobab species studied,four are severely threatened by climate change(Adansonia madagascariensis Baill.,Adansonia fony Baill.,Adansonia za Baill.And Adansonia perrieri Capuron),in part because the ca.50% of original distribution areas does not appear in future species distribution areas.Climate change analysis showed an elevated level of species distribution fragmentation thus increasing risk of genetic diversity loss in future populations of baobabs.The study explored the impact of climate change on baobab trees in Madagascar,and determined the priority and key original habitat protection areas of different baobab trees.This study provides an effective scientific basis for in situ and ex situ conservation of baobab trees in Madagascar,as well as effective suggestions for biodiversity and genetic diversity response to climate change in Madagascar.