Seasonal variability of sediment controls of carbon cycling in an agricultural stream.

Streams and rivers are 'active pipelines' where high rates of carbon (C) turnover can lead to globally important emissions of carbon dioxide (CO) and methane (CH) from surface waters to the atmosphere. Streambed sediments are particularly important in affecting stream chemistry, with rates of biogeochemical activity, and CO and CH concentrations far exceeding those in surface waters. Despite an increase in research on CO and CH in streambed sediments there is a lack of knowledge and insight on seasonal dynamics.