Predicting The Suitable Habitats Of Relic Plants Ginkgo Biloba And Davidia Involucrata

Predicting the suitable habitat range of species and its relationship with climate change is one of the hot scientific issues in ecology and plant protection research.Relict plants which have a long history of origin have important theoretical and practical value.Consequently,it is of great significance to protect the relict plants and predict their suitable habitats.Based on the geographic information data in the two databases of the Global Biodiversity Information Facility and the Chinese Virtual Herbarium and the climate data in the WorldClim database,this paper takes Ginkgo biloba L.and Davidia involucrata Baill.as the research objects,and uses the MaxEnt model to analyze the main environmental factors affecting species distribution,the suitable habitats under present and future climate conditions.The main conclusions arc as follows:(1)MaxEnt model has a good ability to predict the suitable areas of G.biloba and D.involucrata in China,with AUC values more than 0.85.At the same time,according to the results of jackknife method,we can see that the influence of temperature on the distribution of suitable zones of two kinds of relic plants is greater than that of precipitation on the distribution of them.For the distribution of G.biloba,the most important environmental factors affecting are mean temperature of coldest quarter,annual precipitation and mean diurnal range.The most important environmental factors affecting the distribution of D.involucrata are annual precipitation,temperature seasonality and mean diurnal range.(2)The suitable habitats of the two kinds of relic plants are concentrated in three regions of China.The suitable habitats of G.biloba are concentrated irn the southeast China,northern coastal areas of China and scattered sporadically along the southwestern border of China.The suitable habitats of D.involucrata are concentrated in some areas of southwest China,the eastern coastal areas of China and scattered sporadically along the border of Beijing and Eastern Liaoning.(3)Generally speaking,the suitable habitats of both two relic plants under future climatic conditions in China are similar to those under current climatic conditions,but these tend to be more scattered.In 2050s and 2070s,the suitable habitats of G.biloba in China are concentrated in the southeast China,northern coastal areas of China and the southwestern border of China.However,under RCP 6.0 and 8.0,the distribution areas of G.biloba in Shanxi,Hebei and Shaanxi are less than those under current climatic conditions.In 2050s and 2070s,the suitable habitats of D.involucrata in China are concentrated in some parts of Southwest China,eastern coastal areas of China,as well as the border of Beijing and Eastern Liaoning.But the border area between Chongqing and Sichuan is no longer suitable for the growth of D.involucrata.(4)Generally speaking,the centroid of the suitable areas of the two species moved northward under four different CO2 concentrations of RCP 2.6,4.5,6.0 and 8.5.However,the moving direction of the center of mass of Ginkgo biloba in China is northeast,while that of Davidia involucrata is northwest only under the conditions of RCP 4.5 and 6.0 CO2 concentration.Under the conditions of RCP 2.6 and 8.5 CO2 concentration,the moving trend of the center of mass becomes northwest.The purpose of this paper is to study and forecast the suitable habitats of typical relic plants in China,to discuss the impact of environmental factors and climate change on the suitable habitats of these species.This study will also provide ideas and methods for the future study on the prediction of the suitable habitats of other relic plants,and provide theoretical basis for the formulation of conservation policies for both two relic plants.