Hydrological and biogeochemical controls on watershed dissolved organic matter transport: pulse‐shunt concept

Abstract Hydrological precipitation and snowmelt events trigger large “pulse” releases of terrestrial dissolved organic matter ( DOM ) into drainage networks due to an increase in DOM concentration with discharge. Thus, low‐frequency large events, which are predicted to increase with climate change, are responsible for a significant percentage of annual terrestrial DOM input to drainage networks. These same events are accompanied by marked and rapid increases in headwater stream velocity; thus they also “shunt” a large proportion of the pulsed DOM to downstream, higher‐order rivers and aquatic ecosystems geographically removed from the DOM source of origin. Here we merge these ideas into the “pulse‐shunt…