Shifts in Composition, Origin, and Distribution of Invasive Alien Plants in Guangxi, China, over 50 Years

Invasions by alien plants are major global drivers of ecosystem changes and loss of biodiversity. Guangxi is an ecological barrier in southern China that is increasingly being affected by invasive alien plant species. We comprehensively reviewed the literature, compiling and analyzing the long-term changes in species composition, native range, life forms, municipal-scale patterns, and correlates of invasive alien plant richness in Guangxi at three time points (1973, 2010, and 2023). Over the 50-year period, the number of invasive alien plant species markedly increased from 31 species in 1973 to 84 in 2010 and 158 in 2023; the number of families, genera, and species increased 2.05-, 3.75-, and 5.10-fold, respectively. Species native to North America consistently dominated the invasive flora, followed by those native to Africa. The number of species native to South America and Asia increased in the records from 2010 to 2023. Annual herbaceous plants accounted for the largest proportion of invasive species throughout the study period and showed the largest absolute increase in species number. However, no substantial temporal shifts in the overall life-form composition were detected. At the municipal scale, the invasive alien plant richness exhibited pronounced spatial heterogeneity. The invasive alien plant richness was highest in Guilin and Baise in 1973, in Guilin in 2023, followed by Nanning and Baise. Correlation analyses based on 2023 data revealed a significant positive association between invasive alien plant richness and tourism intensity, whereas relationships between population size, gross domestic product, and climatic variables were weak or nonsignificant. Overall, our results document the continued expansion and the spatial differentiation of invasive alien plants in Guangxi over the 50-year period of 1973–2023. These patterns primarily reflect the accumulation in the number of recorded invasive species under a consistent classification framework and should be interpreted with caution given the potential variation in survey effort among periods and cities. The results provide a descriptive baseline for the provincial-scale monitoring, risk assessment, and management of invasive alien plants.