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Fribourg Ecology and Evolution Days 2022: Critical transition, early-warning sign, and coexistence theory


20-21 June 2022

Lang EN Workshop language is English
Responsable de l'activité

Rudolf Rohr


Dr. Rudolf P. Rohr, UNIFR
Prof. Louis-Félix Bersier, UNIFR


A long-standing problem in ecology is how we can quantify the environmental perturbation that a population or a community can tolerate before switching to an undesirable state. This workshop aims to study this essential question from the critical transition and the coexistence theory perspective.

1) Critical transitions arise when systems undergo an abrupt transition in their state. Often, the recovery of the system to its previous state cannot be achieved without intense efforts. A classical example of such a transition is the eutrophication of shallow lakes. Despite the complexity of the underlying dynamics, such regime shifts are preceded by generic early warning signals.

2) Coexistence theory aims to study the conditions for species to coexist at a given place and time. However, the majority of empirical and theoretical understanding comes from two-species systems. The reason is one of practicality: experiments and theory devoted to understanding the interaction of two species are simpler and more tractable. Nonetheless, the focus on pairwise coexistence misses important processes that only emerge in diverse systems of competitors. The maintenance of coexistence in species-rich ecosystems clearly requires a theory that goes beyond the pairwise framework. A multispecies coexistence theory will be introduced and applied to the study of coexistence under changing environment.


Poster (PDF)

Scientific Program (PDF)


Dr. Sonia Kéfi (CNRS, France)

Title: The resilience of ecosystems and their spatial signature

Dr. Vasilis Dakos (CNRS, France):

Title: Quantifying resilience: Tipping points and early-warnings

Prof. Nicolas Loeuille (Sorbonne University, France):

Title: Implications of eco-evolutionary dynamics for the resilience of ecological networks

Dr. Rudolf Rohr (University of Fribourg, Switzerland)

Title: From limiting similarity to coexistence theory

Prof. Serguei Saavedra (MIT)

Title: Understanding multispecies coexistence under unknown heterogenous environment


Monday 20th June

9h30 – 10h30

Dr. Sonia Kéfi

10h45 – 11h45

11h45 – 13h30

Lunch break

13h30 – 14h30

Dr. Vasilis Dakos

14h45 – 15h45

15h45 – 16h15

Coffee break

16h15 – 17h15

Prof. Nicolas Loeuille


Tuesday 21st June

9h00 – 10h00

Prof. Nicolas Loeuille

10h00 – 10h15

Coffee break

10h15 – 11h15

Dr. Rudolf Rohr

11h30 – 12h30

12h30 – 14h00

Lunch break

14h00 – 15h00

Prof. Serguei Saavedra

15h15 – 16h15


University of Fribourg




June 20th-21st 2022

University of Fribourg
PER 21 C130
Bd de Pérolles 90, 1700 Fribourg

Catherine Suarez
@: ecologie-evolution(at)cuso(dot)ch


Reimbursements for CUSO EE students:
- Train ticket, 2nd class, half-fare from the central train station of your university to the place of the activity. Please claim the expenses via your myCUSO account. See HERE for the procedure.

Regarding reimbursement of accommodation, please contact the coordinator of the doctoral programme (ecologie-evolution(at) BEFORE the beginning of the course to check if we have some budget available.
NO reimbursement of accommodation costs without prior agreement
of the coordinator of the doctoral programme.


Late cancellations (after 06.06.2022) or no-show: Administrative fee of 50 CHF will be demanded.


Registration fees:

  • CUSO PhD Students: Free
  • Other CUSO participants (postgraduates, postdocs, etc. from CUSO universities = UNIL, UNIBE, UNINE, UNIFR and UNIGE): 222 CHF
  • External participants, i.e. from non-CUSO universities: 278 CHF (if spaces are available after the 06.06.2022)

External participants (i.e. from a non-CUSO university): Please contact ecologie-evolution(at)cuso(dot)ch before registering! Thanks.

In case of cancellations before June 6th, 2022: free Late cancellations or no-show: Administrative fee of 50 CHF will be demanded.



Deadline for registration 10.06.2022
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