Emergence of a Novel Phase in Population and Community Dynamics Due to Fat-Tailed Environmental Correlations

TL;DR

This paper investigates how power-law correlated environmental noise influences population dynamics, revealing a new intermediate phase characterized by rare environmental stability periods, which alters extinction times and challenges traditional models.

Contribution

It introduces a novel intermediate phase in population dynamics caused by fat-tailed environmental correlations, expanding understanding beyond classical Markovian assumptions.

Findings

Discovery of an intermediate dynamical phase between quenched and annealed regimes.

Extinction time scales non-monotonically with spectral exponent.

Environmental correlations significantly impact population stability.

Abstract

Temporal environmental noise (EN) is a prevalent natural phenomenon that controls population and community dynamics, shaping the destiny of biological species and genetic types. Conventional theoretical models often depict EN as a Markovian process with an exponential distribution of correlation times, resulting in two distinct qualitative dynamical categories: quenched (pertaining to short demographic timescales) and annealed (pertaining to long timescales). However, numerous empirical studies demonstrate a fat-tailed decay of correlation times. Here, we study the consequences of power-law correlated EN on the dynamics of isolated and competing populations. We reveal the emergence of a novel intermediate phase that lies between the quenched and annealed regimes. Within this phase, dynamics are primarily driven by rare, yet not exceedingly rare, long periods of almost-steady environmental conditions. For an isolated population, the time to extinction in this phase exhibits a novel scaling with the abundance, and also a non-monotonic dependence on the spectral exponent.