Predicting the Potential Distribution of the Invasive Plant <i>Alternanthera pungens</i> Kunth Under Climate Change Scenarios in China

<i>Alternanthera pungens</i> Kunth is considered to be less invasive compared to its exotic congener <i>A. philoxeroides</i> (Mart.) Griseb. However, in recent 10 years, it has spread rapidly in Yunnan Province, China. To better understand the species' invasion and distribution, we simulated the potential distribution of <i>A. pungens</i> in China using a MaxEnt model under the current climate scenario and several future climate scenarios, with varying emissions and time frames. The model achieved excellent prediction performance, with <i>A. pungens</i> having an area under the curve value and true skill statistics value of 0.979 and 0.910, respectively. Temperature seasonality and mean temperature of coldest quarter were the greatest predictive environmental variables, with a cumulative contribution of more than 85.3% and a cumulative permutation importance of more than 89.8%. The suitable geographic region of <i>A. pungens</i> is concentrated in southern China. Under the current climate scenarios, projected areas ranked as highly and moderately suitable for <i>A. pungens</i> accounted for 0.31% and 1.03% of the Chinese mainland area, respectively. Under future climate scenarios, the suitable areas for <i>A. pungens</i> in China will expand northwards, with a maximum projected growth rate of 41.4% in the 2070s. This study was the first to show that <i>A. pungens</i> is predicted to expand its range in China in the future. Early warning and monitoring of <i>A. pungens</i> should be pursued, with greater vigilance in southern China to prevent its further spread and invasion.