Gravel bars are sites of increased CO₂ outgassing in stream corridors.

ABSTRACT: Streams are significant sources of CO₂ to the atmosphere. Estimates of CO₂ evasion fluxes (f _CO2) from streams typically relate to the free flowing water but exclude geomorphological structures within the stream corridor. We found that gravel bars (GBs) are important sources of CO₂ to the atmosphere, with on average more than twice as high f _CO2 as those from the streamwater, affecting f _CO2 at the level of entire headwater networks. Vertical temperature gradients resulting from the interplay between advective heat transfer and mixing with groundwater within GBs explained the observed variation in f _CO2 from the GBs reasonably well. We propose that increased temperatures and their gradients within GBs exposed to s

SUBMITTER: Boodoo KS 

PROVIDER: S-EPMC5663935 | biostudies-literature | 2017 Oct

REPOSITORIES: biostudies-literature