Thursday, October 25, 2012, 4:30PM - 5:30PM
RL-1 room 269
Most hypotheses for why dissolved organic matter (DOM) concentrations are changing in many northern rivers relate to changes in the terrestrial environment which then impact the aquatic environment. To assess these hypotheses and make accurate predictions of DOM impact on future water quality, we must better understand the connection of soil and water organic matter, since the two pools are strongly linked. After several years tracing DOM dynamics in Boulder Creek as part of CZO, and also analyzing the water-soluble soil organic matter in Gordon Gulch, a small first-order catchment, the soil OM was clearly chemically different from the water. To try to understand the chemical transformations of the soil organic matter as it enters the aquatic system, we performed a tracer study in Gordon Gulch using chloride as the conservative tracer and freshly leached soil OM as the reactive tracer. Within 35 meters the in-stream processing changed the chemical signal of the soil OM to be indistinguishable from the stream.