The functions of water-dominated ecosystems can be considerably influenced and changed by hydrological fluctuation. The varying states of redox-active substances are of crucial importance here. Researchers at the University of Bayreuth have discovered this, in cooperation with partners from the Universities of Tübingen and Bristol and the Helmholtz Centre for Environmental Research, Halle-Leipzig. They present their discovery in the journal Nature Geoscience. The new study enables a more precise understanding of the biogeochemical processes that contribute to the degradation of pollutants and the reduction of greenhouse gas emissions.