The broad valley bottoms of Headwater Rivers in the Rocky Mountains store the largest amount of above- and below-ground carbon finds a study published in Nature Communications this week. This finding suggests that rapid downstream export of terrestrial carbon does not occur in all mountainous rivers as previously thought.

Headwater rivers receive most of the terrestrial carbon entering a river network from nearby vegetation. Ellen Wohl and colleagues studied the type of carbon storage that occurs along these rivers by estimating organic carbon stored in the valleys of Headwater Rivers of the Rocky Mountain National Park, Colorado, USA. They found that while these valley segments make up less than 25% of the total river length, they can store up to 75% of the carbon. They conclude, therefore, that riverine carbon storage may represent a previously undocumented, but important carbon sink.