Disentangling drivers of mudflat intertidal DOM chemodiversity using ecological models

Microorganisms consume and transform dissolved organic matter (DOM) into various forms. However, it remains unclear whether the ecological patterns and drivers of DOM chemodiversity are analogous to those of microbial communities. Here, a large-scale investigation was conducted along the Chinese coasts to resolve the intrinsic linkages among the complex intertidal DOM pools, microbial communities and environmental heterogeneity. The abundance of DOM molecular formulae best fitted log-normal distribution and followed Taylor’s Law. Distance-decay relationships were observed for labile molecular formulae, while latitudinal diversity gradients were noted for recalcitrant molecular formulae. Latitudinal patterns were also observed for DOM molecular features. Negative cohesion, bacterial diversity, and molecular traits were the main drivers of DOM chemodiversity. Stochasticity analyses demonstrated that determinism dominantly shaped the DOM compositional variations. This study unveils the intrinsic mechanisms underlying the intertidal DOM chemodiversity and microbial communities from ecological perspectives, deepening our understanding of microbially driven chemical ecology.