Rethinking Aquatic Carbon: DOM–Microbes Interactions in a Changing World

Dissolved organic matter (DOM) is one of the largest pools of reactive organic carbon in aquatic ecosystems and plays a central role in regulating microbial metabolism and nutrient and carbon cycling. The concentration, composition and reactivity of DOM in aquatic environments are controlled by a complex interplay between external inputs, in-situ production, and physicochemical transformations. Microbial communities play a key role in these processes by consuming, producing, and transforming DOM, thereby influencing its persistence, bioavailability, and transport across aquatic ecosystems. Nowadays global environmental changes, including climate warming, altered hydrological regimes, land-use change, and cryosphere degradation, are disrupting both DOM dynamics and microbial community structure. Understanding the reciprocal interactions between DOM and microorganisms has therefore become essential for predicting how aquatic carbon cycling and ecosystem functioning will respond to ongoing environmental change.The objective of this Research Topic is to advance the understanding of the reciprocal interactions between dissolved organic matter and microbial communities under global environmental change. While numerous studies have investigated either DOM dynamics or microbial ecology independently, fewer have explicitly addressed the feedbacks linking these two components across spatial and temporal scales. As climate change, hydrological alterations, land-use transformations, and other anthropogenic pressures reshape aquatic ecosystems, DOM-microbes interactions are expected to play an increasingly important role in regulating carbon processing, greenhouse gas emissions, and ecosystem resilience.This Research Topic aims to bring together interdisciplinary studies that integrate biogeochemistry, microbial ecology, hydrology, molecular characterization, and ecosystem science to elucidate the mechanisms driving DOM production, transformation, transport, and degradation. By synthesizing evidence from diverse aquatic environments (e.g., from glacier-fed streams and headwaters to rivers, lakes, estuaries, and coastal waters), we seek to improve predictions of aquatic carbon cycling in a rapidly changing world and identify emerging research directions for understanding ecosystem responses to global change. We welcome contributions that investigate the interactions between dissolved organic matter and microbial communities across freshwater, transitional, and coastal aquatic ecosystems. Topics of interest include, but are not limited to: the effects of climate change, hydrological variability, land-use change, and cryosphere degradation on DOM sources and composition; microbial processing and transformation of DOM; reciprocal feedbacks between microbial diversity, function, and carbon cycling; advances in molecular, spectroscopic, isotopic, and omics approaches for characterizing DOM–microbe interactions; longitudinal and environmental gradients; ecosystem-scale carbon budgets; and predictive models of aquatic carbon dynamics under environmental change.We encourage submissions of Original Research, Reviews, Mini Reviews, Perspectives, Methods, and Data Reports that provide novel insights into the mechanisms linking DOM dynamics, microbial ecology, and aquatic carbon cycling across diverse ecosystems. Topic editors: Morgane Derrien, Simona Retelletti Brogi Source: https://www.frontiersin.org/research-topics/84167/rethinking-aquatic-carbon-dom-microbes-interactions-in-a-changing-world