Native diversity buffers against severity of non-native tree invasions

Determining the drivers of non-native plant invasions is critical for managing native ecosystems and limiting the spread of invasive species1,2. Tree invasions in particular have been relatively overlooked, even though they have the potential to transform ecosystems and economies3,4. Here, leveraging global tree databases5,6,7, we explore how the phylogenetic and functional diversity of native tree communities, human pressure and the environment influence the establishment of non-native tree species and the subsequent invasion severity. We find that anthropogenic factors are key to predicting whether a location is invaded, but that invasion severity is underpinned by native diversity, with higher diversity predicting lower invasion severity. Temperature and precipitation emerge as strong predictors of invasion strategy, with non-native species invading successfully when they are similar to the native community in cold or dry extremes. Yet, despite the influence of these ecological forces in determining invasion strategy, we find evidence that these patterns can be obscured by human activity, with lower ecological signal in areas with higher proximity to shipping ports. Our global perspective of non-native tree invasion highlights that human drivers influence non-native tree presence, and that native phylogenetic and functional diversity have a critical role in the establishment and spread of subsequent invasions.EEA Santa CruzFil: Delavaux, Camille S. Swiss Federal Institute of Technology. Institute of Integrative Biology; SuizaFil: Crowther, Thomas W. Swiss Federal Institute of Technology. Institute of Integrative Biology; SuizaFil: Zohner, Constantin M. Swiss Federal Institute of Technology. Institute of Integrative Biology; SuizaFil: Robmann, Niamh M. Swiss Federal Institute of Technology. Institute of Integrative Biology; SuizaFil: Lauber, Thomas. Swiss Federal Institute of Technology. Institute of Integrative Biology; SuizaFil: van den Hoogen, Johan. Swiss Federal Institute of Technology. Institute of Integrative Biology; SuizaFil: Kuebbing, Sara. Yale University. The Forest School at The Yale School of the Environment; Estados UnidosFil: Liang, Jingjing. Purdue University. Department of Forestry and Natural Resources; Estados UnidosFil: de-Miguel, Sergio. University of Lleida. Department of Crop and Forest Sciences; EspañaFil: de-Miguel, Sergio. Joint Research Unit CTFC–AGROTECNIO–CERCA; EspañaFil: Nabuurs, Gert-Jan. Wageningen University and Research; Países BajosFil: Peri, Pablo Luis. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Santa Cruz; Argentina.Fil: Peri, Pablo Luis. Universidad Nacional de la Patagonia Austral; Argentina.Fil: Peri, Pablo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina.Fil: Maynard, Daniel S. Swiss Federal Institute of Technology. Institute of Integrative Biology; SuizaFil: Maynard, Daniel S. University College London. Department of Genetics, Evolution, and Environment; Reino Unid