The feasibility of equilibria in large ecosystems : a primary but neglected concept in the complexity-stability debate

Dougoud, Michaël (University of Fribourg, Switzerland) ; Vinckenbosch, Laura (University of Fribourg, Switzerland ; Haute école d’ingénierie et de gestion du canton de Vaud, HES-SO // Haute Ecole Spécialisée de Suisse Occidentale) ; Rohr, Rudolf P. (University of Fribourg, Switzerland) ; Bersier, Louis-Félix (University of Fribourg, Switzerland) ; Mazza, Christian (University of Fribourg, Switzerland)

The consensus that complexity begets stability in ecosystems was challenged in the seventies, a result recently extended to ecologically-inspired networks. The approaches assume the existence of a feasible equilibrium, i.e. with positive abundances. However, this key assumption has not been tested. We provide analytical results complemented by simulations which show that equilibrium feasibility vanishes in species rich systems. This result leaves us in the uncomfortable situation in which the existence of a feasible equilibrium assumed in local stability criteria is far from granted. We extend our analyses by changing interaction structure and intensity, and find that feasibility and stability is warranted irrespective of species richness with weak interactions. Interestingly, we find that the dynamical behaviour of ecologically inspired architectures is very different and richer than that of unstructured systems. Our results suggest that a general understanding of ecosystem dynamics requires focusing on the interplay between interaction strength and network architecture.


Mots-clés:
Type d'article:
scientifique
Faculté:
Economie et Services
Ecole:
HEIG-VD
Institut:
IIDE - Institut Interdisciplinaire du Développement de l'Entreprise
Classification:
Economie/gestion
Date:
2018
Pagination:
18 p.
Publié dans
PLOS computational biology
Numérotation (vol. no.):
2018,
DOI:
Le document apparaît dans:



 Notice créée le 2018-04-16, modifiée le 2018-12-05

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