Response of cultivation suitability for Polygonatum kingianum to climate change in China

Polygonatum kingianum is an important cultivated Chinese medicinal herb in southwest China. Assessing the impact of climate change on its cultivation suitability is crucial for optimizing cultivation locations, developing climate-appropriate strategies, and improving both yield and quality. In this study, we employed the MaxEnt model and utilized comprehensive datasets, including 222 occurrence data of P. kingianum, climate data from 707 meteorological stations, soil characteristics, and topography, to evaluate changes in the cultivation suitable distribution in China from 1961 to 2020 at a 1 km² spatial resolution. Our findings revealed that solar radiation from June to October, precipitation from September to November, elevation, isothermality, and precipitation of the coldest quarter were the main environmental variables influencing the cultivation suitability of P. kingianum. The cultivation suitable areas for P. kingianum were primarily located in the southwest mountainous regions of China, encompassing Yunnan, Guizhou, central and eastern Sichuan, and Chongqing Province, with a total coverage of 10.05 × 10⁵ km² (5.53 × 10⁵ km² in forested areas). Over the past 60 years, the cultivation suitability for P. kingianum has increased in the western, northern, and eastern boundaries due to a decrease in solar radiation from June to October. However, it has declined in the central area due to a decrease in precipitation from September to November. The findings of this research contributed to the development of effective cultivation plans and offer guidance for the sustainable management of P. kingianum resources in the face of climate change.