Simulation of Suitable Distribution Areas of Magnolia officinalis in China Based on the MaxEnt Model and Analysis of Key Environmental Variables

Magnolia officinalis Rehder & E.H. Wilson is a deciduous tree in the Magnoliaceae family with extensive medicinal uses in China and Japan, being used to treat symptoms such as indigestion, insomnia, and anxiety. In this study, we used the MaxEnt model to (1) simulate the suitable spatial distribution areas of M. officinalis in China in the current and future periods (2050s and 2090s) and, (2) identify the key environmental variables affecting its spatial distributions by comparing the changes in the center of mass of the suitable areas under the current and projected future climate. The research results show that the current distribution range of M. officinalis is mainly between east longitude 102.2° to 122.2° and north latitude 23.7° to 33.9°, and it is located in the subtropical region of China. In the future, only the high-suitability area under scenario SSP1-2.6 and the low-suitability area under scenario SSP5-8.5 decreased in the 2050s, while the area increased under all other conditions. In the 2050s, the high- and medium-suitability areas under the SSP5-8.5 scenario increased the most, by 54.76% and 20.90%, respectively. Most of the key bio-climatic variables affecting the spatial distributions of M. officinalis are related to temperature and precipitation, and soil, terrain, chemical, and human variables that are also key environmental variables affecting the spatial distributions of M. officinalis . Currently, the suitable spatial distribution centroid of M. officinalis is at (111.71° E, 28.52° N), but it will change in the future climate; although, it will still be located in Hunan Province. This study predicts the spatial distribution areas that are favorable for the cultivation of M. officinalis with the intention of offering an objectively informed identification of suitable areas for the current and future development of this tree crop’s industry.