LAUSR

Significance Communities of interacting species are ubiquitous in Nature. Understanding and predicting these communities’ behaviors informs their engineering in important applications in health and ecological conservation. Despite high phenotypic diversity of organisms across ecosystems, observations show commonalities in their community structures. However, it remains incompletely understood how the species interactions and competition shape the population diversity and community structure. Expanding the predictive understanding of interacting and noisy ecosystems beyond commonly employed limited paradigms, we comprehensively investigate the ecological behaviors described by a minimal ecosystems model of interacting species. We find rich behavior with many unexpected regimes. We apply the insights and implications of our model to the range of behaviors observed experimentally in different ecosystems—from bacteria to the immune system.