Université de Fribourg

Seasonal species interactions minimize the impact of species turnover on the likelihood of community persistence

Saavedra, Serguei ; Rohr, Rudolf Philippe ; Fortuna, Miguel ; Selva, Nuria ; Bascompte, Jordi

In: Ecology, 2015, p. -

Many of the observed species interactions embedded in ecological communities are not permanent, but are characterized by temporal changes that are observed along with abiotic and biotic variations. While work has been done describing and quantifying these changes, little is known about their consequences for species coexistence. Here, we investigate the extent to which changes of species...

Université de Fribourg

Determinants of plant establishment success in a multispecies introduction experiment with native and alien species

Kempel, Anne ; Chrobock, Thomas ; Fischer, Markus ; Rohr, Rudolf Philippe ; Kleunen, Mark van

In: Proceedings of the National Academy of Sciences, 2013, vol. 110, no. 31, p. 12727–12732

Determinants of plant establishment and invasion are a key issue in ecology and evolution. Although establishment success varies substantially among species, the importance of species traits and extrinsic factors as determinants of establishment in existing communities has remained difficult to prove in observational studies because they can be confounded and mask each other. Therefore, we...

Université de Fribourg

Diversity protects plant communities against generalist molluscan herbivores

Fabian, Yvonne ; Sandau, Nadine ; Bruggisser, Odile T. ; Kehrli, Patrik ; Aebi, Alexandre ; Rohr, Rudolf Philippe ; Naisbit, Russell E. ; Bersier, Louis-Félix

In: Ecology and Evolution, 2012, vol. 2, no. 10, p. 2460-2473

Wildflower strips are used to increase natural enemies of crop pests and to conserve insect diversity on farmland. Mollusks, especially slugs, can affect the vegetation development in these strips considerably. Although recent theoretical work suggests that more diverse plant communities will exhibit greater resistance against herbivore pressure, empirical studies are scarce. We conducted a...

Université de Fribourg

Phylogenetic signal in predator–prey body-size relationships

Naisbit, Russell E. ; Kehrli, Patrik ; Rohr, Rudolf Philippe ; Bersier, Louis-Félix

In: Ecology, 2011, vol. 92, no. 12, p. 2183–2189

Body mass is a fundamental characteristic that affects metabolism, life history, and population abundance and frequently sets bounds on who eats whom in food webs. Based on a collection of topological food webs, Ulrich Brose and colleagues presented a general relationship between the body mass of predators and their prey and analyzed how mean predator–prey body-mass ratios differed among...

Université de Fribourg

Modeling food webs: exploring unexplained structure using latent traits

Rohr, Rudolf Philippe ; Scherer, Heike ; Kehrli, Patrik ; Mazza, Christian ; Bersier, Louis-Félix

In: The American Naturalist, 2010, vol. 176, no. 2, p. 170-177

Several stochastic models have tried to capture the architecture of food webs. This approach is interesting, but it is limited by the fact that different assumptions can yield similar results. To overcome this limitation, we develop a purely statistical approach. Body size in terms of an optimal ratio between prey and predator is used as explanatory variable. In 12 observed food webs, this model...