2020 ESA Annual Meeting (August 3 - 6)

COS 137 Abstract - Patterns and drivers of alien plant invasions in European woodlands

Viktoria Wagner1, Milan Chytrý2, Martin Večeřa3, Borja Jiménez-Alfaro4, Jan Pergl5, Stephan Hennekens6, Idoia Biurrun7, Ilona Knollová3, Christian Berg8, Kiril Vassilev9, John S. Rodwell10, Željko Škvorc11, Ute Jandt12, Jörg Ewald13, Florian Jansen14, Ioannis Tsiripidis15, Zoltán Botta-Dukát16, Laura Casella17, Fabio Attorre18, Valerijus Rašomavičius19, Renata Ćušterevska20, Joop Schaminée21, Jörg Brunet22, Jonathan Lenoir23, Jens-Christian Svenning24, Zygmunt Kaçki25, Mária Petrášová-Šibíková26, Urban Šilc27, Itziar García-Mijangos28, Juan Antonio Campos28, Federico Fernández-González29, Thomas Wohlgemuth30, Viktor Onyshchenko31 and Petr Pyšek32, (1)Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada, (2)Masaryk University, (3)Masaryk University, Czech Republic, (4)Universidad de Oviedo, Spain, (5)Department of Invasion Ecology, Institute of Botany Academy of Sciences of the Czech Republic, Pruhonice, Czech Republic, (6)WUR - Alterra, 6700AA Wageningen, Netherlands, (7)University of the Basque Country UPV/EHU,, Spain, (8)University of Graz, Austria, (9)Bulgarian Academy of Sciences, Bulgaria, (10)Lancaster, United Kingdom, (11)University of Zagreb, Croatia, (12)University of Halle-Wittenberg, Germany, (13)Weihenstephan-Triesdorf University of Applied Sciences, Germany, (14)University of Rostock, Germany, (15)Aristotle University of Thessaloniki, Greece, (16)Plant Ecology, Institute of Ecology and Botany, HAS, Vácrátót, (17)ISPRA – Italian National Institute for Environmental Protection and Research, Italy, (18)Sapienza University of Roma, Italy, (19)Nature Research Centre, Lithuania, (20)University of Ss. Cyril and Methodius, Macedonia, The former Yugoslav Republic of, (21)Centre for Ecosystem Studies, WUR - Alterra, 6700AA Wageningen, Netherlands, (22)Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences, Sweden, (23)Department of Ecologie et Dynamique des Systèmes Anthropisés, Université de Picardie Jules Verne, Amiens, France, (24)Department of Biology, Section for Ecoinformatics and Biodiversity, Aarhus University, Aarhus, Denmark, (25)University of Wrocław, Poland, (26)maria.petrasova@savba.sk, Slovakia, (27)Research Centre of the Slovenian Academy of Sciences and Arts, Slovenia, (28)University of the Basque Country UPV/EHU, Spain, (29)Castilla-La Mancha University, Spain, (30)Forest Dynamics, Swiss Federal Research Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, Switzerland, (31)NAS of Ukraine, Ukraine, (32)Department of Ecology, Charles University
Background/Question/Methods

Woodlands cover a third of Europe's territory, yet we know little about the patterns and drivers of alien plant invasions in this vast habitat. We provide an overview of alien plant invasions and disentangle the role of human disturbance and environmental factors in driving patterns across the continent. We extracted survey data from 251,740 plots in the European Vegetation Archive. Plots were classified to EUNIS habitat types, the main habitat classification scheme of the European Union. We assigned a status (alien, native) and geographic origin for species and filtered our plot data extensively. In addition, we reduced our data to a spatially explicit subset and linked it to data on human disturbance proxies (e.g. human population density, degree of soil sealing) and environmental variables (macroclimate, soil) at the landscape scale. We analyzed the presence/absence of alien plants, levels of invasion (relative alien species richness), and alien sum cover per plot in response to human disturbance, habitat type, climate and soil attributes, using random forest analysis and bivariate models.

Results/Conclusions

We found a total of 386 alien plants in European woodlands. Aliens originating from Europe and outside of Europe were equally represented but surprisingly, the latter achieved a much higher frequency. Imported trees and shrubs were overrepresented among alien plants. Riparian woodlands were among the habitats with the highest level of invasion. By contrast, coniferous forests tended to have lowest levels of invasion. Furthermore, habitat type emerged as the most important predictor of levels of invasion and played only a minor role for the alien sum cover. By comparison, human disturbance was only a weak predictor of all invasion response variables. The overall patterns of invasions might reflect a historic introduction or planting bias towards alien species from outside of Europe, especially trees and shrubs. The weak link to human disturbance indicates that aliens are able to establish under a wide variety of human disturbance regimes or that disturbance plays a more important role at a smaller (local) scale. The strong relationship between alien plant invasions and habitat type suggests that intrinsic habitat properties and habitat preferences of introduced alien plants drive invasions across European woodlands.