Emergence of ecological structure and species rarity from fluctuating metabolic strategies

Abstract: Ecosystems often demonstrate the coexistence of numerous species competing for limited resources, with pronounced rarity and abundance patterns. A potential driver of such coexistence is environmental fluctuations that favor different species over time. However, how to include and treat such temporal variability in existing consumer-resource models is still an open problem. In this study, we examine the role of correlated temporal fluctuations in metabolic strategies within a stochastic consumer-resource framework, reflecting change of species behavior in response to the environment. In some conditions, we are able to solve analytically the species abundance distributions, through path integral formalism. Our results reveal that stochastic dynamic metabolic strategies induce community structures that align more closely with empirical ecological observations and contribute to the violation of the Competitive Exclusion Principle (CEP). The degree of CEP violation is maximized under intermediate competition strength, leading to an intermediate competition hypothesis. Furthermore, when non-neutral effects are present, maximal biodiversity is achieved for intermediate values of the amplitude of fluctuations. This work not only challenges traditional ecological paradigms, but also establishes a robust theoretical framework for exploring how temporal dynamics and stochasticity drive biodiversity and community.