Invasive alien ant species pose serious threats to agricultural production, ecosystems, and human health in China. Solenopsis invicta Buren is the most destructive and aggressive invasive alien ant in China, causing serious agricultural and urban economic losses and public health concerns. Estimating its spatial distribution and ecological niche in China is crucial for S. invicta prevention and control. Based on 4195 occurrence records (4096 invasive occurrence records and 99 native occurrence records) and 10 environmental variables, we estimated the potential suitable area and ecological niche of S. invicta in China using the ensemble model and ‘ecospat’ package in R language. The mean AUC, KAPPA, and TSS values of the ensemble model were 0.989, 0.901, and 0.901, respectively, indicating that the ensemble model was better than the single-species distribution model for the simulation. Temperature, precipitation, and human factors are important variables that influence the distribution of S. invicta. Our results showed that the ecological niche similarity and equivalency test results showed that the ecological niches between native areas and China were not equivalent (D = 0.46, p = 0.001), but were more similar than would be expected by chance (p = 0.003). Under current climatic conditions, the total potential suitable area for S. invicta is 192.89 × 10⁴ km² in China, accounting for 20.09% of the land area in China; this land is mainly distributed in Hainan, Taiwan, Guangdong, Guangxi, Fujian, Zhejiang, Jiangsu, Anhui, Hubei, Hunan, Jiangxi, Guizhou, Yunnan, Chongqing, Sichuan, and Henan. Under future climatic conditions, the potential suitable areas of S. invicta will further increase, while the highly suitable areas will shift to higher latitudes. We suggest that early warning and monitoring of S. invicta in the central and northern areas of China should be strengthened to prevent its further spread.

Tagetes minuta L., a member of the Tageftes genus belonging to the Asteraceae family, is a well-documented exotic plant native to South America that has become established in China. In this study, 784 occurrence records and 12 environmental variables were used to predict the potential geographical distributions (PGDs) of T. minuta under current and future climatic changes using an optimized MaxEnt model. The results showed that (1) three out of the twelve variables contributed the most to the model performance: isothermality (bio3), precipitation in the driest quarter (bio17), and precipitation in the warmest quarter (bio18); (2) the PGDs of T. minuta under the current climate covered 62.06 × 10⁴ km², mainly in North, South, and Southwest China; and (3) climate changes will facilitate the expansion of the PGDs of T. minuta under three shared socioeconomic pathways (SSP 1-2.6, SSP2-4.5, and SSP5-8.5) in both the 2030s and 2050s. The centroid of suitable habitats under SSP2-4.5 moved the longest distance. T. minuta has the capacity to expand in China, especially in Yunnan, where there exist no occurrence records. Customs, ports, and adjacent regions should strengthen the quarantine of imported goods and mobile personnel for T. minuta, and introduced seedlings should be isolated to minimize their introduction risk.

Global trade facilitates multiple introductions of alien species, yet the role of genetic admixture between divergent lineages in driving invasion success remains debated. Here, we address this question by analyzing dynamic genetic changes across invasion stages in the dioecious weed Amaranthus palmeri, introduced to China from North and South America. Combining chloroplast phylogeography with nuclear genetic analyses, we systematically investigated genetic changes in populations at casual, naturalized, invasive, and dispersal stages. Initial casual populations originated from distinct North and South American lineages, but all established populations (naturalized, invasive, dispersal) retained only North American haplotypes. South American genetic introgression decreased progressively during invasion (from 34% in naturalized to 3% in dispersal populations), accompanied by declining inbreeding coefficients. Established populations exhibited high inter-population crosses within the North American lineage (54–60%), maintaining genetic diversity and overcoming bottlenecks. Our findings demonstrate that invasion success in A. palmeri may be driven by gene flow within the North American lineage, rather than admixture between divergent lineages. These findings enhance our understanding of the genetic mechanisms underpinning plant invasions, highlighting lineage-specific management as a critical strategy for controlling invasive populations.