Refine my results

Document type

Specific Collection


Université de Fribourg

Gene flow from foreign provenances into local plant populations: Fitness consequences and implications for biodiversity restoration

Crémieux, Lisèle ; Bischoff, Armin ; Müller-Schärer, Heinz ; Steinger, Thomas

In: American Journal of Botany, 2010, vol. 97, p. 94-100

Long-distance transplantation of seed material as done in restoration programs has raised concerns about the risks associated with the introduction of maladapted genotypes that may hybridize with neighboring native conspecifics and decrease local population fitness (outbreeding depression). We studied the consequences of gene flow from foreign provenances into local populations in the common...

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

Potential contribution of natural enemies to patterns of local adaptation in plants

Crémieux, Lisèle ; Bischoff, Armin ; Šmilauerová, Majka ; Lawson, Clare S. ; Mortimer, Simon R. ; Doležal, Jiří ; Lanta, Vojtěch ; Edwards, Andrew R. ; Brook, Alex J. ; Tscheulin, Thomas ; Macel, Mirka ; Lepš, Jan ; Müller-Schärer, Heinz ; Steinger, Thomas

In: New Phytologist, 2008, vol. 180, no. 2, p. 524 - 533

Genetic differentiation among plant populations and adaptation to local environmental conditions are well documented. However, few studies have examined the potential contribution of plant antagonists, such as insect herbivores and pathogens, to the pattern of local adaptation.Here, a reciprocal transplant experiment was set up at three sites across Europe using two common plant species, Holcus...

Université de Fribourg

The importance of plant provenance and genotypic diversity of seed material used for ecological restoration

Bischoff, Armin ; Steinger, Thomas ; Müller-Schärer, Heinz

In: Restoration Ecology, 2009///doi:10.1111/j.1526-100X.2008.00454.x

The increased translocation of plant species for biodiversity restoration and habitat creation has provoked a debate on provenance and genotypic diversity of the used plant material. Nonlocal provenances are often not adapted to the local environmental conditions, and low population genotypic diversity may result in genetic bottlenecks hampering successful establishment. We tested provenance...

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

Reliable confidence intervals in quantitative genetics: narrow-sense heritability

Fabbro, Thomas ; Davison, Anthony C. ; Steinger, Thomas

In: Theoretical and Applied Genetics, 2008, vol. 115, no. 7, p. 933-944

Many quantitative genetic statistics are functions of variance components, for which a large number of replicates is needed for precise estimates and reliable measures of uncertainty, on which sound interpretation depends. Moreover, in large experiments the deaths of some individuals can occur, so methods for analysing such data need to be robust to missing values. We show how confidence...

Université de Fribourg

Predicting adaptive evolution under elevated atmospheric CO₂ in the perennial grass Bromus erectus

Steinger, Thomas ; Stephan, André ; Schmid, Bernhard

In: Global Change Biology, 2007, vol. 13, no. 5, p. 1028-1039

Increasing concentrations of CO₂ in the atmosphere are likely to affect the ecological dynamics of plant populations and communities worldwide, yet little is known about potential evolutionary consequences of high CO₂. We employed a quantitative genetic framework to examine how the expression of genetic variation and covariation in fitness-related traits, and thus, the evolutionary potential...

Université de Fribourg

Climate vs. soil factors in local adaptation of two common plant species

Macel, Mirka ; Lawson, Clare S. ; Mortimer, Simon R. ; Šmilauerova, Marie ; Bischoff, Armin ; Crémieux, Lisèle ; Doležal, Jirí ; Edwards, Andrew R. ; Lanta, Vojtch ; Bezemer, T. Martijn ; Putten, Wim H. van der ; Igual, José M. ; Rodriguez-Barrueco, Claudino ; Müller-Schärer, Heinz ; Steinger, Thomas

In: Ecology, 2007, vol. 88, no. 2, p. 424–433

Evolutionary theory suggests that divergent natural selection in heterogeneous environments can result in locally adapted plant genotypes. To understand local adaptation it is important to study the ecological factors responsible for divergent selection. At a continental scale, variation in climate can be important while at a local scale soil properties could also play a role. We designed an...

Université de Fribourg

Detecting local adaptation in widespread grassland species – the importance of scale and local plant community

Bischoff, Armin ; Crémieux, Lisèle ; Smilauerova, Marie ; Lawson, Clare S. ; Mortimer, Simon R. ; Dolezal, Jiri ; Lanta, Vojtech ; Edwards, Andrew R. ; Brook, Alex J. ; Macel, Mirka ; Leps, Jan ; Steinger, Thomas ; Müller-Schärer, Heinz

In: Journal of Ecology, 2006, vol. 94, p. 1130-1142

1 Adaptation of plant populations to local environments has been shown in many species but local adaptation is not always apparent and spatial scales of differentiation are not well known. In a reciprocal transplant experiment we tested whether: (i) three widespread grassland species are locally adapted at a European scale; (ii) detection of local adaptation depends on competition with the...