Université de Fribourg

Testing the Evolution of Increased Competitive Ability (EICA) hypothesis in a novel framework

Handley, Richard J. ; Steinger, Thomas ; Treier, Urs A. ; Müller-Schärer, Heinz

In: Ecology, 2008, vol. 89, no. 2, p. 407–417

The “evolution of increased competitive ability” (EICA) hypothesis proposes that escape from natural enemies, e.g., after transcontinental introductions, alters the selection regime because costly defenses no longer enhance fitness. Such an evolutionary loss of defenses enables resources to be directed toward growth or other traits improving performance. We tested the EICA hypothesis in a...

Université de Fribourg

Modeling the impact of a biocontrol agent, Puccinia lagenophorae, on interactions between a crop, Daucus carota, and a weed, Senecio vulgaris

Frantzen, J. ; Müller-Schärer, Heinz

In: Biological Control, 2006, vol. 37, no. 3, p. 301-306

The impact of a biocontrol agent spreading from a point source on crop–weed interactions was modeled. The model encompassed: (i) severity of crop–weed competition as affected by a rust pathogen, (ii) velocity of spread of the rust pathogen, and (iii) density of infected plants introduced in the weed population as starting points (inoculum sources) for an epidemic. The model was parameterized...