Emergence of ecological structure and species rarity from fluctuating metabolic strategies

TL;DR

This paper develops a stochastic consumer-resource model with fluctuating metabolic strategies to explain ecological diversity and species abundance distributions, aligning theoretical predictions with empirical observations.

Contribution

It introduces an analytical framework for modeling temporal fluctuations in metabolic strategies and their impact on community structure and biodiversity.

Findings

Community diversity increases with resource fluctuation amplitude.

Species extinction occurs when species-to-resource ratio exceeds a critical value.

Maximum biodiversity occurs at intermediate ratios and fluctuation amplitudes.

Abstract

Ecosystems frequently display the coexistence of diverse species under resource competition, typically resulting in skewed distributions of rarity and abundance. A potential driver of such coexistence is environmental fluctuations that favor different species over time. How to include and treat such temporal variability in existing consumer-resource models is still an open problem. In this work, we study correlated temporal fluctuations in species' resource uptake rates -- i.e. metabolic strategies -- within a stochastic consumer-resource framework. In a biologically relevant regime, we are able to find analytically the species abundance distributions through the path integral formalism. Our results reveal that stochastic dynamic metabolic strategies induce community structures that align more closely with empirical ecological observations. Within this framework, ecological communities show a higher diversity than expected under static competitive scenarios. We find that all species become extinct when the ratio of the number of species to the number of resources exceeds a critical threshold. Conversely, diversity peaks at intermediate values of the same ratio. Furthermore, when metabolic strategies of different species are different on average, maximal biodiversity is achieved for intermediate values of the amplitude of fluctuations. This work establishes a robust theoretical framework for exploring how temporal dynamics and stochasticity drive biodiversity and community structure.