title: Disturbance is the key to plant invasions in cold environments.
abstract: Until now, nonnative plant species were rarely found at high elevations and latitudes. However, partly because of climate warming, biological invasions are now on the rise in these extremely cold environments. These plant invasions make it timely to undertake a thorough experimental assessment of what has previously been holding them back. This knowledge is key to developing efficient management of the increasing risks of cold-climate invasions. Here, we integrate human interventions (i.e., disturbance, nutrient addition, and propagule input) and climatic factors (i.e., temperature) into one seed-addition experiment across two continents: the subantarctic Andes and subarctic Scandinavian mountains (Scandes), to disentangle their roles in limiting or favoring plant invasions. Disturbance was found as the main determinant of plant invader success (i.e., establishment, growth, and flowering) along the entire cold-climate gradient, explaining 40-60% of the total variance in our models, with no indication of any facilitative effect from the native vegetation. Higher nutrient levels additionally stimulated biomass production and flowering. Establishment and flowering displayed a hump-shaped response with increasing elevation, suggesting that competition is the main limit on invader success at low elevations, as opposed to low-growing-season temperatures at high elevations. Our experiment showed, however, that nonnative plants can establish, grow, and flower well above their current elevational limits in high-latitude mountains. We thus argue that cold-climate ecosystems are likely to see rapid increases in plant invasions in the near future as a result of a synergistic interaction between increasing human-mediated disturbances and climate warming.
authors.affiliation: Centre of Excellence Plant and Vegetation Ecology, University of Antwerp, 2610 Wilrijk, Belgium; jonas.lembrechts@uantwerpen.be.
authors.forename: Jonas J
authors.identifier: 0000-0002-1933-0750
authors.initials: JJ
authors.lastname: Lembrechts
authors.affiliation: Laboratorio de Invasiones Biológicas, Facultad de Ciencias Forestales, Universidad de Concepción, 4030000 Concepción, Chile.|Institute of Ecology and Biodiversity, 8320000 Santiago, Chile.
authors.forename: Aníbal
authors.initials: A
authors.lastname: Pauchard
authors.affiliation: Unité de Recherche Ecologie et Dynamique des Systèmes Anthropisés, Formations de Recherche en Évolution 3498 CNRS, Université de Picardie Jules Verne, 80037 Amiens Cedex 1, France.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Lenoir
authors.affiliation: Grupo de Ecología de Invasiones, Universidad Nacional del Comahue, Instituto de Investigaciones en Biodiversidad y Medioambiente, Consejo Nacional de Investigaciones Científicas y Técnicas, C.P. 8400, Bariloche, Argentina.
authors.forename: Martín A
authors.initials: MA
authors.lastname: Nuñez
authors.affiliation: Faculté des Sciences, Université d'Angers, 49000 Angers, France.
authors.forename: Charly
authors.initials: C
authors.lastname: Geron
authors.affiliation: Centre of Excellence Plant and Vegetation Ecology, University of Antwerp, 2610 Wilrijk, Belgium.
authors.forename: Arne
authors.initials: A
authors.lastname: Ven
authors.affiliation: Laboratorio de Invasiones Biológicas, Facultad de Ciencias Forestales, Universidad de Concepción, 4030000 Concepción, Chile.
authors.forename: Pablo
authors.initials: P
authors.lastname: Bravo-Monasterio
authors.affiliation: Grupo de Estudios Ambientales, Universidad de Magallanes, 6200000 Punta Arenas, Chile.
authors.forename: Ernesto
authors.initials: E
authors.lastname: Teneb
authors.affiliation: Centre of Excellence Plant and Vegetation Ecology, University of Antwerp, 2610 Wilrijk, Belgium.
authors.forename: Ivan
authors.initials: I
authors.lastname: Nijs
authors.affiliation: Department of Biodiversity and Natural Environment, Research Institute for Nature and Forest (INBO), 1070 Brussels, Belgium.
authors.forename: Ann
authors.initials: A
authors.lastname: Milbau
mesh_terms: D000531:Altitude; D002980:Climate; D057231:Climate Change; D003080:Cold Temperature; D017753:Ecosystem; D058865:Introduced Species / Q000639:trends*; D063245:Plant Development / Q000502:physiology*; D018521:Plant Physiological Phenomena; D010944:Plants / Q000378:metabolism*; D012639:Seeds; D013696:Temperature
keywords: alien plant species; biological invasions; climate change; disturbance; mountains