Université de Fribourg

Comparing species interaction networks along environmental gradients: Networks along environmental gradients

Pellissier, Loïc ; Albouy, Camille ; Bascompte, Jordi ; Farwig, Nina ; Graham, Catherine ; Loreau, Michel ; Maglianesi, Maria Alejandra ; Melián, Carlos J. ; Pitteloud, Camille ; Roslin, Tomas ; Rohr, Rudolf ; Saavedra, Serguei ; Thuiller, Wilfried ; Woodward, Guy ; Zimmermann, Niklaus E. ; Gravel, Dominique

In: Biological Reviews, 2018, vol. 93, no. 2, p. 785–800

Knowledge of species composition and their interactions, in the form of interaction networks, is required to understand processes shaping their distribution over time and space. As such, comparing ecological networks along environmental gradients represents a promising new research avenue to understand the organization of life. Variation in the position and intensity of links within networks...

Université de Fribourg

A structural approach for understanding multispecies coexistence

Saavedra, Serguei ; Rohr, Rudolf P. ; Bascompte, Jordi ; Godoy, Oscar ; Kraft, Nathan J. B. ; Levine, Jonathan M.

In: Ecological Monographs, 2017, p. -

Although observations of species-rich communities have long served as a primary motivation for research on the coexistence of competitors, the majority of our empirical and theoretical understanding comes from two-species systems. How much of the coexistence observed in species rich communities results from indirect effects among competitors that only emerge in diverse systems remains poorly...

Université de Fribourg

Persist or produce: a community trade-off tuned by species evenness

Rohr, Rudolf P. ; Saavedra, Serguei ; Peralta, Guadalupe ; Frost, Carol M. ; Bersier, Louis-Félix ; Bascompte, Jordi ; Tylianakis, Jason M.

In: The American Naturalist, 2016, vol. 188, no. 4, p. 411–422

Understanding the effects of biodiversity on community persistence and productivity is key to managing both natural and production systems. Because rare species face greater danger of extinction, species evenness, a measure of how similar abundances are across species in a community, is seen as a key component of biodiversity. However, previous studies have failed to find a consistent...

Université de Fribourg

How structurally stable are global socioeconomic systems?

Saavedra, Serguei ; Rohr, Rudolf P ; Gilarranz, Luis J ; Bascompte, Jordi

In: Journal of The Royal Society Interface, 2014, vol. 11, no. 100, p. 20140693

The stability analysis of socioeconomic systems has been centred on answering whether small perturbations when a system is in a given quantitative state will push the system permanently to a different quantitative state. However, typically the quantitative state of socioeconomic systems is subject to constant change. Therefore, a key stability question that has been under-investigated is how...

Université de Fribourg

Stock fluctuations are correlated and amplified across networks of interlocking directorates

Saavedra, Serguei ; Gilarranz, Luis J ; Rohr, Rudolf P. ; Schnabel, Michael ; Uzzi, Brian ; Bascompte, Jordi

In: EPJ Data Science, 2014, vol. 3, no. 1, p. 30

Traded corporations are required by law to have a majority of outside directors on their board. This requirement allows the existence of directors who sit on the board of two or more corporations at the same time, generating what is commonly known as interlocking directorates. While research has shown that networks of interlocking directorates facilitate the transmission of information between...

Université de Fribourg

Nested species interactions promote feasibility over stability during the assembly of a pollinator community

Saavedra, Serguei ; Rohr, Rudolf P. ; Olesen, Jens M. ; Bascompte, Jordi

In: Ecology and Evolution, 2016, p. -

The foundational concepts behind the persistence of ecological communities have been based on two ecological properties: dynamical stability and feasibility. The former is typically regarded as the capacity of a community to return to an original equilibrium state after a perturbation in species abundances and is usually linked to the strength of interspecific interactions. The latter is the...

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

Components of phylogenetic signal in antagonistic and mutualistic networks.

Rohr, Rudolf P. ; Bascompte, Jordi

In: The American Naturalist, 2014, vol. 184, no. 5, p. 556–564

Recent studies have shown a phylogenetic signal in the structure of ecological networks, making the point that evolutionary history is important in explaining network architecture. However, this previous work has focused on either antagonistic (i.e., predator-prey) or mutualistic networks and has used different methodologies. Thus, a comparative assessment of both the frequency and the strength...

Université de Fribourg

On the structural stability of mutualistic systems

Rohr, Rudolf P. ; Saavedra, Serguei ; Bascompte, Jordi

In: Science, 2014, vol. 345, no. 6195, p. 1253497

In theoretical ecology, traditional studies based on dynamical stability and numerical simulations have not found a unified answer to the effect of network architecture on community persistence. Here, we introduce a mathematical framework based on the concept of structural stability to explain such a disparity of results. We investigated the range of conditions necessary for the stable...