The Tibetan plateau, with complex and diverse ecosystems, is an important ecological security barrier to China. However, climate change and the spread of invasive plant species have imperiled the once pristine and diverse ecosystem of the region. To prevent the further spread and control of invasive plants, it is important to delineate the potential distribution patterns of alien invasive plants at the regional scale across Tibet and understand their responses to climate change. Galinsoga parviflora Cav., a member of the family Asteraceae, is an annual herbaceous plant distributed globally as an invasive weed and possesses characteristics that make it highly invasive, such as a strong ability to proliferate and disperse. The species is also known to have an allelopathic effect. There has been no report on the spatial distribution of G. parviflora in Tibet. Using field survey data, we investigated the risk of G. parviflora invasion and its impacts on the ecological safety of Tibet. We employed the MaxEnt model using the R language and SPSS software to optimize and select model parameters and data. We acquired various environmental variables along with current and future climate change scenarios (two carbon emission scenarios, SSP126 and SSP585, for the years 2050 and 2090) to predict the geographic distribution and potential risk areas in Tibet that G. parviflora can invade. The MaxEnt model accurately predicted the distribution of G. parviflora in Tibet with an average AUC of 0.985. The most suitable environmental conditions in which G. parviflora performed the best in Tibet included a mean annual temperature of 6.2–10.0 °C and an elevation range of 2672–3744 m above sea level. Our results indicate that low precipitation during the coldest quarter of the year (mean temperature −2–3 °C) was the most important variable predicting G. parviflora distribution. The results also showed that the species was hardly found when precipitation in the coldest quarter exceeded 155 mm. The current potential invasion risk areas for G. parviflora included the river valleys of central, southeastern, and eastern Tibet. With future climate change scenarios (i.e., SSP126, SSP585), the suitable habitats for G. parviflora distribution will likely shift to northwest regions from the southeast. Particularly under the highest carbon emission scenario (i.e., SSP585), the potential risk area expands more rapidly, and the center of distribution shifts to northwest regions. These findings provide useful information about the current and future changes in G. parviflora distribution in Tibet, which is crucial for the comprehensive and proactive management and control of G. parviflora under future climate change.

Datura stramonium, which is originally native to Mexico, has been recognized as an invasive species following its introduction to China, where it has proliferated extensively. Despite its widespread impact, the mechanisms driving the invasion of D. stramonium remain insufficiently understood. Therefore, gaining insight into these mechanisms is essential for the development of effective strategies to prevent and control its further invasion. This study aims to elucidate the factors contributing to the successful invasion of D. stramonium in Tibet by examining genetic differentiation, allelopathic potential, and niche characteristics of its populations. Our findings reveal the following: (1) The genetic variation within 15 populations of D. stramonium is predominantly intra-populational, lacking distinct genealogical phylogeographic structure, and is indicative of recent population expansion. This suggests that human-mediated dispersal has played a significant role in the invasion of D. stramonium in Tibet. (2) Allelopathic assays demonstrate that extracts from various parts of D. stramonium exhibit significant inhibitory effects on the germination of Hordeum vulgare var. coeleste and Pisum sativum seeds. (3) D. stramonium exhibits the highest niche breadth within the plant community, coupled with a pronounced competitive ability for environmental resources. The invasion of D. stramonium poses a substantial threat to the diversity of local plant species. Consequently, the formulation of scientific management measures is of critical importance to prevent and control the invasion of D. stramonium and preserve biodiversity in the invaded area.