Geographical distribution and potential distribution prediction of thirteen species of Citrus L. in China.

Using DIVA-GIS software to study the spatial accumulation of Citrus species, an important economic crop in China. Draw the distribution maps of Citrus to concerning altitude and vegetation, and use DIVA-GIS' Bioclim ecological model and maximum information entropy model Maxent software to estimate the potential distribution areas of various Citrus species. The results show that the Citrus genus is located in the south of Qinling Mountains, mainly in the southwest of China and the coast of southeastern China. Sichuan and Chongqing are the most densely distributed regions of Citrus. The distribution of Citrus is closely related to the vegetation type and altitude. The vegetation types in the distribution area is evergreen broad-leaved forest, evergreen shrub, deciduous broad-leaved forest, mixed-leaf forest coverage area, deciduous coniferous forest, farmland, trees, other vegetation coverage, and evergreen coniferous forest. The current potential distribution area of Citrus is mainly in Guizhou, Hubei, Hunan, Guangdong, Guangxi, Yunnan, Sichuan, Chongqing, and other provinces and municipalities and their borders, while the potential distribution area in the future moves northward and enter Henan and southern Gansu. At the same time, climate warming changes the distribution of suitable areas of Citrus, which makes the suitable areas of C. sinensis Osbeck, C. reticulata Blanco, and other crops greatly increased. Planning the planting area will effectively improve the yield and quality in the future. Planning presents new challenges.