Stability criteria for complex ecosystems

  title={Stability criteria for complex ecosystems},
  author={Stefano Allesina and Si Tang},
Forty years ago, May proved that sufficiently large or complex ecological networks have a probability of persisting that is close to zero, contrary to previous expectations. May analysed large networks in which species interact at random. However, in natural systems pairs of species have well-defined interactions (for example predator–prey, mutualistic or competitive). Here we extend May’s results to these relationships and find remarkable differences between predator–prey interactions, which… 

Stability criteria for complex microbial communities

The authors explore the stability of microbial networks based on the consumption and exchange of resources, showing that asymmetry in crossfeeding relationships can destabilize networks.

Stability of ecosystems enhanced by species-interaction constraints.

It is argued that this constrained interaction structure-limiting the total interactions for each species-is biologically plausible, and it is shown that constrained interaction structures-a constant row sum in the interaction matrix-prevent extinctions from occurring.

The stability of mutualism

  • L. Stone
  • Environmental Science
    Nature Communications
  • 2020
Through a random matrix model that considers species density, the author shows that mutualistic interactions can, in fact, enhance population density at equilibrium and increase community resilience to perturbation.

No complexity–stability relationship in empirical ecosystems

A stability analysis of 116 quantitative food webs sampled worldwide finds that classic descriptors of complexity (species richness, connectance and interaction strength) are not associated with stability in empirical food webs, and concludes that empiricalfood webs have several non-random properties contributing to the absence of a complexity–stability relationship.

The geometry of coexistence in large ecosystems

A geometrical framework to study the range of conditions necessary for feasible coexistence in both mutualistic and consumer-resource systems is developed and the geometric shape of the feasibility domain is characterized, thereby identifying the direction of perturbations that are more likely to cause extinctions.

Dynamical systems on large networks with predator-prey interactions are stable and exhibit oscillations.

An exact theory is developed for the spectral distribution and the leading eigenvalue of the corresponding sparse Jacobian matrices of large dynamical systems defined on sparse, random graphs with predator-prey, competitive, and mutualistic interactions that reveals that the nature of local interactions have a strong influence on system's stability.

The balance of interaction types determines the assembly and stability of ecological communities

This work presents a model with saturating benefits from mutualisms and sequentially assembled communities and shows that such communities are internally stable for any level of diversity and any combination of species interaction types.

Disentangling nestedness from models of ecological complexity

Nestedness is, at best, a secondary covariate rather than a causative factor for biodiversity in mutualistic communities, and analysis of complex networks should be accompanied by analysis of simpler, underpinning mechanisms that drive multiple higher-order network properties.

Cooperation promotes biodiversity and stability in a model ecosystem

A stochastic model is proposed which is appropriate for species communities with mutualistic/commensalistic interactions and finds that, in the large system size limit, any number of species can coexist for a very general class of interaction networks and that the stationary state is globally stable.

Stability-instability transition in tripartite merged ecological networks

This work considers tripartite networks constructed by merging two bipartite networks, one mutualistic and one antagonistic, and derives results that show how the spectrum undergoes an eigenvalue phase transition, which leads to an abrupt destabilisation of the network as the ratio of mutualists to antagonists is increased.



Network structure, predator–prey modules, and stability in large food webs

St stability is highly robust to perturbations of interaction strength, and is largely a property of structure driven by predator–prey loops with the stability of these small modules cascading into that of the whole network.

Network structural properties mediate the stability of mutualistic communities.

It is shown that structural properties can alter the stability of mutualistic communities characterized by nonlinear functional responses among the interacting species, and that interplay between the structure and function of ecological networks in general and consideration of mutualists interactions in particular may be key to understanding complexity-stability relationships of biological communities as a whole.

Stability and diversity of ecological communities

An application of May's analytical solution for large matrices in which each element by itself is stable showed that a complex system perched near this transition region is subject to a self-generating catastrophe upon only a minor modification of system parameters.

The stability of real ecosystems

Most current theoretical work on whole ecological communities is based on a conception of community dynamics (see, for example, refs 1, 2) in which the community resides in a neighbourhood of

The architecture of mutualistic networks minimizes competition and increases biodiversity

It is shown that nestedness reduces effective interspecific competition and enhances the number of coexisting species, and that a nested network will naturally emerge if new species are more likely to enter the community where they have minimal competitive load.

Weak trophic interactions and the balance of nature

The results show that weak to intermediate strength links are important in promoting community persistence and stability, and data on interaction strengths in natural food webs indicate that food-web interaction strengths are indeed characterized by many weak interactions and a few strong interactions.

Equilibrium and Nonequilibrium Concepts in Ecological Models

Mathematical models and empirical studies have revealed two potentially disruptive influences on ecosystems; (1) instabilities caused by nonlinear feedbacks and time-lags in the interactions of

Stability of Ecological Communities and the Architecture of Mutualistic and Trophic Networks

It is concluded that strong variations in the stability of architectural patterns constrain ecological networks toward different architectures, depending on the type of interaction.

Variability in interaction strength and implications for biodiversity

The species richness of theoretical communities can greatly depend on the correlation between interaction strengths, an issue that so far has gone unreported and may profoundly increase the potential for stable co-existence of a highly species-rich community.

Weak interactions, omnivory and emergent food-web properties

  • M. EmmersonJ. Yearsley
  • Environmental Science
    Proceedings of the Royal Society of London. Series B: Biological Sciences
  • 2004
It is found that skewed interaction strengths are an emergent property of stable omnivorous communities, and that this skew towards weak interactions creates a dynamic constraint maintaining omnivory.