Rivers transport carbon from continents to oceans. Surprisingly, this carbon has often been found to be centuries old, not originating from contemporary plant biomass. This can be explained by anthropogenic disturbance of soils or discharge of radiocarbon–depleted wastewater. However, land enclosure and channel bypassing transformed many rivers from anabranching networks to single–channel systems with overbank sediment accumul...

Reductions in emissions have successfully led to a regional decline in atmospheric nitrogen depositions over the past 20 years. By analyzing long‐term data from 110 mountainous streams draining into German drinking water reservoirs, nitrate concentrations indeed declined in the majority of catchments. Furthermore, our meta‐analysis indicates that the declining nitrate levels are linked to the release of dissolved iron to strea...