Université de Fribourg

Biological invasion of oxeye daisy (Leucanthemum vulgare) in North America: Pre-adaptation, post-introduction evolution, or both?

Stutz, Sonja ; Mráz, Patrik ; Hinz, Hariet L. ; Müller-Schärer, Heinz ; Schaffner, Urs

In: PLOS ONE, 2018, vol. 13, no. 1, p. e0190705

Species may become invasive after introduction to a new range because phenotypic traits pre-adapt them to spread and become dominant. In addition, adaptation to novel selection pressures in the introduced range may further increase their potential to become invasive. The diploid Leucanthemum vulgare and the tetraploid L. ircutianum are native to Eurasia and have been introduced to North...

Université de Fribourg

Can enemy release explain the invasion success of the diploid Leucanthemum vulgare in North America?

Stutz, Sonja ; Štajerová, Kateřina ; Hinz, Hariet L. ; Müller-Schärer, Heinz ; Schaffner, Urs

In: Biological Invasions, 2016, p. 1–15

Enemy release is a commonly accepted mechanism to explain plant invasions. Both the diploid Leucanthemum vulgare and the morphologically very similar tetraploid Leucanthemum ircutianum have been introduced into North America. To verify which species is more prevalent in North America we sampled 98 Leucanthemum populations and determined their ploidy level. Although polyploidy has repeatedly...

Université de Fribourg

Prospects for biological control of Ambrosia artemisiifolia in Europe: learning from the past

Gerber, E. ; Schaffner, Urs ; Gassmann, A. ; Hinz, H. L. ; Seier, M. ; Müller-Schärer, Heinz

In: Weed Research, 2011, vol. 51, no. 6, p. 559–573

The recent invasion by Ambrosia artemisiifolia (common ragweed) has, like no other plant, raised the awareness of invasive plants in Europe. The main concerns regarding this plant are that it produces a large amount of highly allergenic pollen that causes high rates of sensitisation among humans, but also A. artemisiifolia is increasingly becoming a major weed in agriculture. Recently, chemical...

Université de Fribourg

Is there rapid evolutionary response in introduced populations of tansy ragwort, Jacobaea vulgaris, when exposed to biological control ?

Rapo, Carole ; Müller-Schärer, Heinz ; Vrieling, Klaas ; Schaffner, Urs

In: Evolutionary Ecology, 2010, vol. 24, no. 5, p. 1081-1099

Differences in the herbivore community between a plant’s native (specialists and generalists) and introduced range (almost exclusively generalists) may lead to the evolution of reduced allocation to defences against specialist herbivores in the introduced range, allowing for increased allocation to competitive ability and to defences against generalist herbivores. Following this logic, the...