Axmanová¹, V. Kalusová1., M. Chytrý¹, J. Danihelka¹, J. Dengler2, J. Pergl3, P. Pyšek3,4, F. Attorre5, I. Biurrun6, S. Boch7, T. Conradi8, R. Gavilán García9, S. M. Hennekens10, B. Jiménez-Alfaro11, I. Knollová1, A. Kuzemko1,12, J. Lenoir13, J. Medvecká14, J. E. Moeslund15, J.-C. Svenning15, I. Tsiripidis16 and K. Vassilev17
1Department of Botany and Zoology, Masaryk University, Brno, Czech Republic, 2Institute of Natural Resource Management (IUNR), Zurich University of Applied Sciences (ZHAW), Wädenswil, Switzerland, 3Department of Invasion Ecology, Institute of Botany, Czech Academy of Sciences, Průhonice, Czech Republic, 4Department of Ecology, Faculty of Science, Charles University, Prague, Czech Republic, 5Department of Environmental Biology, Sapienza University of Rome, Rome, Italy, 6Department of Plant Biology and Ecology, University of the Basque Country, Bilbao, Spain, 7 WSL Swiss Federal Research Institute, Birmensdorf, Switzerland, 8Plant Ecology, Bayreuth Center for Ecology and Environmental Research (BayCEER), University of Bayreuth, Bayreuth, Germany, 9Unit of Botany, Faculty of Pharmacy, Complutense University, Madrid, Spain, 10Wagenigen Environmental Research (Alterra), Wagenigen University and Research, Wagenigen, The Netherlands, 11Research Unit of Biodiversity (CSIC/UO/PA), Mieres, Spain, 12M.G. Kholodny Institute of Botany of the National Academy of Sciences of Ukraine, Ukraine, 13Ecologie et Dynamiques des Systèmes Anthropisés, Université de Picardie Jules Verne, Amiens, France, 14Institute of Botany, Plant Science and Biodiversity Centre, Slovak Academy of Sciences, Bratislava, Slovakia, 15Department of Bioscience, Aarhus University, Aarhus, Denmark, 16Department of Botany, School of Biology, Aristotle University of Thessaloniki, Greece, 17Institute of Biodiversity and Ecosystem Research, Bulgarian Academy of Sciences, Sofia, Bulgaria
e-mail: email@example.com (V. Kalusová)
The human-related spread of alien plants has serious environmental and socioeconomic impacts. One of the most important goals of invasion biology is to identify habitats that are most threatened by invasive plants and mechanisms responsible for their high vulnerability. We studied a wide range of European grasslands as recipients of alien plant species to describe general patterns of invasion at the continental scale. We used comprehensive vegetation data available in the European Vegetation Archive to assess (i) which grassland types in Europe have high levels of invasions, (ii) which alien species are the most successful invaders in these habitats, and (iii) how habitat levels of invasion and invaders change across different European countries and along major environmental gradients.
Our initial dataset contained more than 300,000 vegetation plots assigned to EUNIS grassland habitats sampled in geographically delimited European regions (excl. Macaronesia, Anatolia and Cyprus). For the final dataset (consisting of 91,293 plots), we only selected plots that were sampled from 1970 onwards, 1–100 m2 in size, and subject to geographically stratified random resampling based on countries’ sizes to avoid oversampling of particular regions and enable comparisons among them. We updated the DAISIE database of alien taxa in Europe using available national and regional alien species checklists, local expert assignments and the Euro+Med database to assign alien or native status to plant taxa in vegetation plots in different countries. We only considered neophytes (i.e. alien species introduced to a country after 1500 AD) and divided them, based on their native range, in those that originated outside versus within Europe.
We present an overview of EUNIS grassland habitats with their levels of invasion (i.e. the mean proportion of neophytes in all plots assigned to a habitat) and a list of successful invaders at the European scale. We also compare the levels of invasion in particular European countries along the major geographical and environmental gradients across the continent.