To clarify the occurrence trends of poisonous weeds in grasslands under future climate change， and to scientifically prevent their spread and reduce economic losses in the livestock industry， this study based on the distribution data of five frequently occurring grassland poisonous weeds in the Ili River Valley： Sophora alopecuroides， Aconitum leucostomum， Xanthium spinosum， Rumex thianschanicus， and Peganum harmala—and combined with 55 influencing factors， employed the Maximum Entropy model to explore the impact of climate change on the occurrence trends of these five grassland poisonous weeds. The results showed that the prediction models for the five grassland poisonous weeds all had an accuracy greater than 0.8， indicating high precision. Under four future climate scenarios， the total potential occurrence area of Aconitum leucostomum decreased， while that of the other four grassland poisonous weeds increased. Under the medium-to-high emission scenario （SSP370）， grassland poisonous weeds were more prone to expansion and posed greater risks. In terms of migration direction， in the future， Aconitum leucostomum， Rumex thianschanicus， and Peganum harmala would mainly migrate southward， Sophora alopecuroides would migrate eastward， and Xanthium spinosum would migrate toward the southeast and northeast， with an overall trend of grassland poisonous weeds migrating toward lower latitudes. Under the four future climate scenarios， the area of overlapping zones for multiple grassland poisonous weed species increased， with the largest overlapping area occurring under the high-emission scenario （SSP585）. In conclusion， continuous increases in carbon emissions will exacerbate the spread and harm of grassland poisonous weeds.

Grassland poisonous weed  /  MaxEnt model  /  Trend analysis