Invasive annual plants increasingly threaten Xinjiang's arid ecosystems, yet their colonization patterns and ecological consequences remain understudied. We evaluated four high-impact invaders-Xanthium spinosum L. (X. spinosum), Solanum rostratum Dunal (S. rostratum), Ambrosia trifida L. (A. trifida), and Ambrosia artemisiifolia L. (A. artemisiifolia)-by monitoring plant diversity and productivity across residential area, roadside, farmland ecotone, and wasteland habitats pre- and post-invasion. Annual invaders were most prevalent in residential areas and farmland ecotones, though A. artemisiifolia and A. trifida occurred ubiquitously. Invasion suppressed native productivity, reducing living biomass, density, and projective cover by 68.43%, 28.82%, and 53.42%, respectively. Productivity declines were strongest in wastelands, under S. rostratum invasion, and in areas with high soil moisture/low human disturbance. Conversely, invasions enhanced diversity metrics: Simpson's, Shannon, and Equitability indices increased by 25.62%, 30.33%, and 17.20%, respectively, while the Berger-Parker index decreased by 25.01%. Diversity improvements peaked in roadsides, under A. trifida invasion, and high soil moisture/low human disturbance. The findings of this study provide reference data for further monitoring and managing the four most damaging invasive species in the Xinjiang region.