Format: ORAL

Hubert KOZDRA1 Lamine BENSADDEK2 Solene Roque2 Thomas KICHEY2 Quentin METTRAY3 Stphane DREANO4 Anna GAZDA1 Annie GUILLER2

1 University of Agriculture, Krakow, Poland 2 EDYSAN UMR CNRS UPJV 7058, Amiens, France 3 Les entreprises du paysage, Paris, France 4 IGDR UMR CNRS UR1 6290, France

Combined with climate change and anthropogenic activities, biological invasions have rapidly become one of the worlds most costly ecological problems, significantly altering ecosystems, disrupting agriculture and spreading diseases. Understanding the circumstances of invasions under changing environmental conditions and unravelling the ecological and evolutionary mechanisms underlying invasive success are major challenges for improving our ability to predict and therefore mitigate biological invasions. Acer pseudoplatanus is a tree species native to central and southern Europe, introduced in various parts of the world for either ornamental or timber production benefits. Its high reproductive potential and remarkable capacity for dispersal, recruitment and establishment enable it to become a redoubtable invader. Thanks to its high seed production, which can be propagated over long distances, and its rapid growth, the sycamore maple is a threat to natural forests, particularly rare for species. The study focused on the ecophysiological, genetic and biochemical variation in native (Poland, Germany, Switzerland), naturalized (north eastern France) and invasive (north western France, Ireland, United States, New Zealand) ranges of A. pseudoplatanus. Aims were to infer the demogenetic history and to reconstruct the routes of invasion of the species, as well as to reveal traits facilitating its invasion in response to new habitat pressures. In particular, the comparison of the profiles of the hypoglycine A metabolite involved in the etiology of atypical equine myopathy disease, of which no clinic is documented in its native range, allowed to shed light on the relationship between invasiveness and allelopathy which is the basis of the New Weapons Hypothesis (NWH).