Generalized Lotka-Volterra systems with quenched random interactions and saturating nonlinear response

Fuente: arXiv
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Main Authors: Zenari, Marco, Ferraro, Francesco, Azaele, Sandro, Maritan, Amos, Suweis, Samir
Format: Preprint
Published: 2025
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_version_ 1866915765245968384
author Zenari, Marco
Ferraro, Francesco
Azaele, Sandro
Maritan, Amos
Suweis, Samir
author_facet Zenari, Marco
Ferraro, Francesco
Azaele, Sandro
Maritan, Amos
Suweis, Samir
contents The generalized Lotka-Volterra (GLV) equations with quenched random interactions have been extensively used to investigate the stability and dynamics of complex ecosystems. However, the standard linear interaction model suffers from pathological unbounded growth, especially under strong cooperation or heterogeneity. This work addresses that limitation by introducing a Monod-type saturating nonlinear response into the GLV framework. Using Dynamical Mean Field Theory, we derive analytical expressions for the species abundance distribution in the Unique Fixed Point phase and show the suppression of unbounded dynamics. Numerical simulations reveal a rich dynamical structure in the Multiple Attractor phase, including a transition between high-dimensional chaotic and low-volatility regimes, governed by interaction symmetry. These findings offer a more ecologically realistic foundation for disordered ecosystem models and highlight the role of nonlinearity and symmetry in shaping the diversity and resilience of large ecological communities.
format Preprint
id arxiv_https___arxiv_org_abs_2506_04056
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Generalized Lotka-Volterra systems with quenched random interactions and saturating nonlinear response
Zenari, Marco
Ferraro, Francesco
Azaele, Sandro
Maritan, Amos
Suweis, Samir
Populations and Evolution
The generalized Lotka-Volterra (GLV) equations with quenched random interactions have been extensively used to investigate the stability and dynamics of complex ecosystems. However, the standard linear interaction model suffers from pathological unbounded growth, especially under strong cooperation or heterogeneity. This work addresses that limitation by introducing a Monod-type saturating nonlinear response into the GLV framework. Using Dynamical Mean Field Theory, we derive analytical expressions for the species abundance distribution in the Unique Fixed Point phase and show the suppression of unbounded dynamics. Numerical simulations reveal a rich dynamical structure in the Multiple Attractor phase, including a transition between high-dimensional chaotic and low-volatility regimes, governed by interaction symmetry. These findings offer a more ecologically realistic foundation for disordered ecosystem models and highlight the role of nonlinearity and symmetry in shaping the diversity and resilience of large ecological communities.
title Generalized Lotka-Volterra systems with quenched random interactions and saturating nonlinear response
topic Populations and Evolution
url https://arxiv.org/abs/2506.04056