Université de Fribourg

Biological Flora of the British Isles: Ambrosia artemisiifolia

Essl, Franz ; Biró, Krisztina ; Brandes, Dietmar ; Broennimann, Olivier ; Bullock, James M. ; Chapman, Daniel S. ; Chauvel, Bruno ; Dullinger, Stefan ; Fumanal, Boris ; Guisan, Antoine ; Karrer, Gerhard ; Kazinczi, Gabriella ; Kueffer, Christoph ; Laitung, Beryl ; Lavoie, Claude ; Leitner, Michael ; Mang, Thomas ; Moser, Dietmar ; Müller-Schärer, Heinz ; Petitpierre, Blaise ; Richter, Robert ; Schaffner, Urs ; Smith, Matt ; Starfinger, Uwe ; Vautard, Robert ; Vogl, Gero ; Lippe, Moritz von der ; Follak, Swen

In: Journal of Ecology, 2015, vol. 103, no. 4, p. 1069–1098

This account presents information on all aspects of the biology of Ambrosia artemisiifolia L. (Common ragweed) that are relevant to understanding its ecology. The main topics are presented within the standard framework of the Biological Flora of the British Isles: distribution, habitat, communities, responses to biotic factors, responses to environment, structure and physiology, phenology, floral...

Université de Fribourg

Contrasting spatio-temporal climatic niche dynamics during the eastern and western invasions of spotted knapweed in North America

Broennimann, Olivier ; Mráz, Patrik ; Petitpierre, Blaise ; Guisan, Antoine ; Müller-Schärer, Heinz

In: Journal of Biogeography, 2013///n/a–n/a

Aim: The spotted knapweed (Centaurea stoebe), a plant native to south-east and central Europe, is highly invasive in North America. We investigated the spatio-temporal climatic niche dynamics of the spotted knapweed in North America along two putative eastern and western invasion routes. We then considered the patterns observed in the light of historical, ecological and evolutionary...

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....

Université de Fribourg

Evidence of climatic niche shift during biological invasion

Broennimann, Olivier ; Treier, Urs A. ; Müller-Schärer, Heinz ; Thuiller, W. ; Peterson, A. T. ; Guisan, Antoine

In: Ecology Letters, 2007, vol. 10, no. 8, p. 701-709

Niche-based models calibrated in the native range by relating species observations to climatic variables are commonly used to predict the potential spatial extent of species’ invasion. This climate matching approach relies on the assumption that invasive species conserve their climatic niche in the invaded ranges. We test this assumption by analysing the climatic niche spaces of Spotted...