Martín Forés, IreneCastro Parga, IsabelAcosta Gallo, BelénPozo Lira, AlejandroSánchez Jardón, LauraMiguel Garcinuño, José Manuel DeOvalle, CarlosCasado González, Miguel Ángel2023-06-172023-06-172016-121752-9921, ESSN: 1752-993X10.1093/jpe/rtw043https://hdl.handle.net/20.500.14352/18118Aims Alien species are commonly considered as harmful weeds capable of decreasing native biodiversity and threatening ecosystems. Despite this assumption, little is known about the long-term patterns of the native–alien relationships associated with human disturbed managed landscapes. This study aims to elucidate the community dynamics associated with a successional gradient in Chilean Mediterranean grasslands, considering both native and alien species. Methods Species richness (natives and aliens separately) and life-form (annuals and perennials) were recorded in four Chilean post-agricultural grazed grasslands each covering a broad successional gradient (from 1 to 40 years since crop abandonment). A detrended correspondence analysis (DCA), mixed model effects analyses and correlation tests were conducted to assess how this temporal gradient influenced natives and aliens through community dynamics. Important Findings Our results show different life-form patterns between natives and aliens over time. Aliens were mainly represented by annuals (especially ruderals and weeds), which were established at the beginning of succession. Annual aliens also predominated at midsuccessional stages, but in old grasslands native species were slightly more representative than alien ones within the community. In the late successional states, positive or no correlations at all between alien and native species richness suggested the absence of competition between both species groups, as a result of different strategies in occupation of the space. Community dynamics over time constitute a net gain in biodiversity, increasing natives and maintaining a general alien pool, allowing the coexistence of both. Biotic interactions including facilitation and/or tolerance processes might be occurring in Chilean post-agricultural grasslands, a fact that contradicts the accepted idea of the alien species as contenders.engjournal articlehttps://academic.oup.com/jpe/article/9/6/682/2624176/Alien-plant-species-coexist-over-time-with-native?searchresult=1restricted access581.5(83)Community dynamicsLand abandonment gradientLifeformLivestock grazingSuccessional gradientEcología (Biología)2401.06 Ecología animal