Abstract:

Aims: pecies distribution models (SDMs) are commonly employed to predict and manage invasive species. However, these prediction efforts often assume the stability of a species’ realized niche, which does not hold true during the invasion process. As a result, predicting the actual distribution of the invasive species based on early distribution data presents a challenge. Our study investigated the ability of the SDMs, fitted with the historical distribution records of Chromolaena odorata, to predict its distribution.

Methods: Based on the native and Chinese distribution records of C. odorata from 1934 to 2024, covering both its native range and its distribution in China, the temporal and spatial shifts in the species’ realized niche were analyzed using the NicheA and COUE (centroid shift, overlap, unfilling, and expansion) frameworks. A series of SDMs, encompassing both past distribution periods and a future climate scenario for 2040, were constructed to analyze the species’ spatial and temporal distribution patterns of C. odorata, incorporating its dispersal capabilities.

Results(1) The stability of the realized climatic niche of C. odorata in China exhibited the highest stability prior to 1989 (niche stability = 1), with a slight niche expanded observed after 1989 (1934-2009: niche expansion (NE) = 0.08; 1934-2024: NE = 0.09), mainly originating from Taiwan Province, while the realized climatic niche in other provinces remained stable. (2) The SDMs based on past species records accurately predicted the known distribution of C. odorata (test data AUC: 0.873-0.887, omission rate: 0.131-0.152). Different time-period models produced similar potential distributions. Compared to pre-1969 period, the potential distribution of C. odorata in China has increased by 71.8%-77.3%, with northward expansion into southern Guizhou Province, north of Guangxi and Guangdong provinces, and northern Jiangxi Province, and eastward expansion into Fujian. (3) Under future climate scenarios and considering both short- and long-distance dispersal capability, by 2040, C. odorata is expected to reach the border of Chongqing and Sichuan, and expand further into southern Zhejiang and eastern Jiangxi.

Conclusion: Over the 90 years since C. odorata invaded China, its realized climate niche has remained stable. SDMs developed during the early invasion stages provided valuable insights, although they tended to underestimate the potential distribution compared to models built in later stages. This study provides a reference for constructing SDMs and highlights priorities for managing C. odorata in China.

Key words: biological invasion, Chromolaena odorata, historical distribution data, climate niches, transferability