Reconstructing long-term records of dissolved CO2

✍ Scribed by Fred Worrall; Tim Burt

• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 303 KB
• Volume: 19
• Category: Article
• ISSN: 0885-6087
• DOI: 10.1002/hyp.5635

✦ Synopsis

The dissolved CO 2 concentration of stream waters is an important component of the terrestrial carbon cycle. This study reconstructs long-term records of dissolved CO 2 concentration for the outlets of two large catchments (818 and 586 km 2 ) in northern England. The study shows that:

1. The flux of dissolved CO 2 from the catchments (as carbon per catchment area), when adjusted for that which would be carried by the river water at equilibrium with the atmosphere, is between 0 and 0Ð39 t km 2 year 1 for the River Tees and between 0 and 0Ð65 t km 2 year 1 for the River Coquet. 2. The flux of dissolved CO 2 is closely correlated with dissolved organic carbon (DOC) export and is unrelated to dissolved CO 2 export from the headwaters of the study catchments. 3. The evasion rate of CO 2 from the rivers (as carbon per stream area) is between 0Ð0 and 1Ð49 kg m 2 year 1 , and calculated in-stream productions of CO 2 are estimated as between 0Ð5 and 2Ð5% of the stream evasion rate. 4. By mass balance, it is estimated that 8% of the annual flux of DOC is lost within the streams of the catchment.

The study shows that the loss of CO 2 from the streams of the Tees catchment is between 3Ð1 and 7Ð5 kt year 1 (as carbon) for the River Tees, which is the same order as annual CH 4 flux from peats within the catchment and approximately 50% of the net CO 2 exchange to the peats of the catchment.