title: Global thermal niche models of two European grasses show high invasion risks in Antarctica.
abstract: The two non-native grasses that have established long-term populations in Antarctica (Poa pratensis and Poa annua) were studied from a global multidimensional thermal niche perspective to address the biological invasion risk to Antarctica. These two species exhibit contrasting introduction histories and reproductive strategies and represent two referential case studies of biological invasion processes. We used a multistep process with a range of species distribution modelling techniques (ecological niche factor analysis, multidimensional envelopes, distance/entropy algorithms) together with a suite of thermoclimatic variables, to characterize the potential ranges of these species. Their native bioclimatic thermal envelopes in Eurasia, together with the different naturalized populations across continents, were compared next. The potential niche of P. pratensis was wider at the cold extremes; however, P. annua life history attributes enable it to be a more successful colonizer. We observe that particularly cold summers are a key aspect of the unique Antarctic environment. In consequence, ruderals such as P. annua can quickly expand under such harsh conditions, whereas the more stress-tolerant P. pratensis endures and persist through steady growth. Compiled data on human pressure at the Antarctic Peninsula allowed us to provide site-specific biosecurity risk indicators. We conclude that several areas across the region are vulnerable to invasions from these and other similar species. This can only be visualized in species distribution models (SDMs) when accounting for founder populations that reveal nonanalogous conditions. Results reinforce the need for strict management practices to minimize introductions. Furthermore, our novel set of temperature-based bioclimatic GIS layers for ice-free terrestrial Antarctica provide a mechanism for regional and global species distribution models to be built for other potentially invasive species.
authors.affiliation: Área de Biodiversidad, Department de Biología, Geología, Física y Química Inorgánica, Universidad Rey Juan Carlos, C/Tulipán S/N, Móstoles, Madrid, 28933, Spain.
authors.forename: Luis R
authors.initials: LR
authors.lastname: Pertierra
authors.affiliation: Department de Biogeografía y Cambio Global, Museo Nacional de Ciencias Naturales, C/José Abascal 2, Madrid, Madrid, 28006, Spain.
authors.forename: Pedro
authors.initials: P
authors.lastname: Aragón
authors.affiliation: Antarctic Conservation and Management, Australian Antarctic Division, 203 Channel Hwy, Kingston, TAS, 7050, Australia.|Centre for Biodiversity and Conservation Science, School of Biological Sciences, The University of Queensland, St Lucia, Qld, 4072, Australia.
authors.forename: Justine D
authors.initials: JD
authors.lastname: Shaw
authors.affiliation: Antarctic Conservation and Management, Australian Antarctic Division, 203 Channel Hwy, Kingston, TAS, 7050, Australia.
authors.forename: Dana M
authors.initials: DM
authors.lastname: Bergstrom
authors.affiliation: Antarctic Conservation and Management, Australian Antarctic Division, 203 Channel Hwy, Kingston, TAS, 7050, Australia.
authors.forename: Aleks
authors.initials: A
authors.lastname: Terauds
authors.affiliation: Área de Biodiversidad, Department de Biología, Geología, Física y Química Inorgánica, Universidad Rey Juan Carlos, C/Tulipán S/N, Móstoles, Madrid, 28933, Spain.
authors.forename: Miguel Ángel
authors.initials: MÁ
authors.lastname: Olalla-Tárraga
mesh_terms: D000864:Antarctic Regions; D004463:Ecology; D005544:Forecasting; D006801:Humans; D058865:Introduced Species; D006109:Poaceae / Q000254:growth & development*; D012621:Seasons; D013696:Temperature
keywords: Poaceae; biosecurity protocols; non-native species management; nonanalogous climate; species distribution models