New research shows that iron oxide minerals, specifically goethite, act as a filter for dissolved organic matter in soil and water. By selectively adsorbing complex aromatic compounds, these minerals change which carbon molecules remain available for microbes to eat, directly affecting how much carbon is stored versus released as greenhouse gas. The study highlights that pH levels significantly alter this process, with different bacterial groups targeting specific carbon fractions over time. This molecular insight helps improve how we predict carbon cycling in wetlands and iron-rich soils, which is critical for accurate carbon accounting and sequestration models.
