Université de Fribourg

Evidence for a combination of pre-adapted traits and rapid adaptive change in the invasive plant Centaurea stoebe

Henery, Martin L. ; Bowman, Gillianne ; Mráz, Patrik ; Treier, Urs A. ; Gex-Fabry, Emilie ; Schaffner, Urs ; Müller-Schärer, Heinz

In: Joural of Ecology, 2010, vol. 98, no. 4, p. 800–813

1. Introduced plants have the potential to rapidly evolve traits of ecological importance that may add to their innate potential to become invasive. During invasions, selection may favour genotypes that are already pre-adapted to conditions in the new habitat and, over time, alter the characteristics of subsequent generations. 2. Spotted knapweed (Centaurea stoebe) occurs in two predominantly...

Université de Fribourg

Shift in cytotype frequency and niche space in the invasive plant Centaurea maculosa

Treier, Urs A. ; Broennimann, Olivier ; Normand, Signe ; Guisan, Antoine ; Schaffner, Urs ; Steinger, Thomas ; Müller-Schärer, Heinz

In: Ecology, 2009, vol. 90, no. 5, p. 1366-1377

Polyploidy is often assumed to increase the spread and thus the success of alien plant species, but few empirical studies exist. We tested this hypothesis with Centaurea maculosa Lam., a species native to Europe and introduced into North America approximately 120 years ago where it became highly invasive. We analyzed the ploidy level of more than 2000 plants from 93 native and 48 invasive C....