New research shows that iron oxide minerals, such as goethite, act as a filter for dissolved organic matter in soils and wetlands. By selectively binding to complex aromatic compounds that resist decay, these minerals effectively sequester carbon and prevent it from being broken down by microbes. This process varies based on pH levels, with higher acidity increasing the mineral's ability to sort organic molecules. Understanding this interaction helps scientists better predict carbon fluxes and the long-term stability of natural carbon sinks in different environmental conditions.
