ABSTRACT.- Questions: Degradation of facilitative interactions of native species can play an important role in the establishment and expansion of invasive plants in communities. We evaluated the relationship between the level of invasion of Cynodon dactylon and the arbuscular mycorrhizal colonization of the native Paspalum notatum in Uruguayan grasslands, which were either extensively managed (natural vegetation [NG]) or oversown with exotic legumes and fertilized with phosphorus (NG + LP). Specifically, we investigated whether increasing invasion levels were associated with reductions in P. notatum mycorrhizal colonization, growth, and nutrient content. Location: Uruguayan grasslands of Río de la Plata grasslands region. © 2025 International Association for Vegetation Science.