Potential geographical distribution of Liquidambar formosana in China under the situation of climate change

Liquidambar formosana is a highly valued fast-growing deciduous broad-leaved tree species in China, particularly favored for afforestation on barren lands and in mixed afforestation projects. This study aims to investigate the potential geographic distribution of Liquidambar formosana under future climate change scenarios and its response to environmental factors. The research is intended to provide a comprehensive understanding of how environmental variables influence the potential distribution of Liquidambar formosana, with the ultimate goal of offering robust and scientifically grounded theoretical support for the effective utilization of its germplasm resources.

Using a combination of 19 climate factors and 3 terrain factors, the MaxEnt model was employed to analyze the current distribution and predict the potential distribution dynamics of Liquidambar formosana for two future periods (2041-2060s, 2081-2100s) under three distinct climate scenarios (SSP126, SSP245, SSP585).

1) The MaxEnt model simulation AUC value was 0.915, indicating high simulation accuracy; 2) Five factors play a dominant role in the distribution of Liquidambar formosana, including temperature seasonality (280-770 ℃), mean diurnal temperature range (4.8-8.0 ℃), annual mean precipitation (1 426-4 017 mm), precipitation coefficient of variation (23.8-62.5), and driest month precipitation (36-216 mm); 3) The current suitable area for Liquidambar formosana is 229.06×10⁴ km², accounting for 23.9% of China's total area. Under different emission scenarios, the size of the suitable area is SSP585 > SSP245 > SSP126 > Current, and within the same emission scenario, the size of the suitable area is 2090s > 2050s > Current, with the suitable area increasing with increasing emissions and time; 4) Currently, Liquidambar formosana's suitable habitat is mainly found in Hunan, Jiangxi, Guangxi, Zhejiang, Fujian, Anhui, Jiangsu, and Taiwan. Under the three climate scenarios considered, the potential suitable habitat for Liquidambar formosana is expected to expand northward in the future. However, there will be a certain degree of reduction in suitable habitats in the western regions. The expanding areas are primarily located in the northern parts of Henan, central Shaanxi, central Shandong, and southern Liaoning. On the other hand, the shrinking areas are mainly concentrated in the southwestern parts of Yunnan, southern Xizang, and Taiwan. In the future, during the 2050s and 2090s under the three scenarios, Liquidambar formosana is predicted to exhibit an overall trend of shifting its centroid of potential suitable distribution towards the northeast.

This study underscores that temperature and precipitation are the primary drivers shaping both the current and future geographic distribution of Liquidambar formosana. The species exhibits adaptability to higher concentrations of greenhouse gases in the future, resulting in an expanding suitable area. Liquidambar formosana holds promise as an excellent choice for broad-leaved afforestation initiatives, with the potential to enhance forest landscapes, foster mixed forests, improve forest habitats, and elevate overall forest quality.