Plant invasion in Mediterranean Europe: current hotspots and future scenarios

Cao Pinna, L. , Gallien, L., Pollock, L. J., Axmanová, I., Chytrý, M., Malavasi, M., Acosta, A. T. R., Campos, J. A. and Carboni, M. (2024) Plant invasion in Mediterranean Europe: current hotspots and future scenarios. Ecography, e07085. (doi: 10.1111/ecog.07085) (Early Online Publication)

Abstract

The Mediterranean Basin has historically been subject to alien plant invasions that threaten its unique biodiversity. This seasonally dry and densely populated region is undergoing severe climatic and socioeconomic changes, and it is unclear whether these changes will worsen or mitigate plant invasions. Predictions are often biased, as species may not be in equilibrium in the invaded environment, depending on their invasion stage and ecological characteristics. To address future predictions uncertainty, we identified invasion hotspots across multiple biased modelling scenarios and ecological characteristics of successful invaders. We selected 92 alien plant species widespread in Mediterranean Europe and compiled data on their distribution in the Mediterranean and worldwide. We combined these data with environmental and propagule pressure variables to model global and regional species niches, and map their current and future habitat suitability. We identified invasion hotspots, examined their potential future shifts, and compared the results of different modelling strategies. Finally, we generalised our findings by using linear models to determine the traits and biogeographic features of invaders most likely to benefit from global change. Currently, invasion hotspots are found near ports and coastlines throughout Mediterranean Europe. However, many species occupy only a small portion of the environmental conditions to which they are preadapted, suggesting that their invasion is still an ongoing process. Future conditions will lead to declines in many currently widespread aliens, which will tend to move to higher elevations and latitudes. Our trait models indicate that future climates will generally favour species with conservative ecological strategies that can cope with reduced water availability, such as those with short stature and low specific leaf area. Taken together, our results suggest that in future environments, these conservative aliens will move farther from the introduction areas and upslope, threatening mountain ecosystems that have been spared from invasions so far.

• Item Type: Articles
• Additional Information: L. Cao Pinna was supported by a PhD fellowship from Roma Tre University. M. Carboni and A. T. R. Acosta acknowledge the support of NBFC to Roma Tre University, funded by the Italian Ministry of University and Research, PNRR, Missione 4 Componente 2, ‘Dalla ricerca all’impresa’, Investimento 1.4, Project CN00000033. Irena Axmanová and Milan Chytrý were supported by the Czech Science Foundation (EXPRO grant no. 19-28491X).
• Keywords: Alien plant invasion, climate change, future scenarios, hotspots, invasive species, Mediterranean, spatial predictions, species distribution models.
• Status: Early Online Publication
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Cao Pinna, Dr Luigi

Creator Roles

Cao Pinna, L.: Conceptualization, Data curation, Formal analysis, Investigation, Methodology, Validation, Visualization, Writing – original draft, Writing – review and editing

• Authors: Cao Pinna, L., Gallien, L., Pollock, L. J., Axmanová, I., Chytrý, M., Malavasi, M., Acosta, A. T. R., Campos, J. A., and Carboni, M.
• College/School: College of Science and Engineering > School of Mathematics and Statistics > Statistics
• Journal Name: Ecography
• Publisher: Wiley
• ISSN: 0906-7590
• ISSN (Online): 1600-0587
• Published Online: 05 March 2024
• Copyright Holders: Copyright © 2024 The Authors
• First Published: First published in Ecography 2024
• Publisher Policy: Reproduced under a Creative Commons license