Importance of CO2 evasion from small boreal streams

Abstract

Boreal lakes are known to be supersaturated with CO2 and to be significant sources of CO2 to the atmosphere. In this study it is shown that small boreal streams are relatively more supersaturated with CO 2 and also represent an important source of CO2 evasion to the atmosphere from boreal catchments. Small boreal streams account for an annual (ice-free seasons) average of 8.0% and a seasonal high of 34.4% of the total CO2 evaded from streams and lakes. A seasonal pattern is found, with evasion from streams being greatest during the summer and least during the spring. The evasion of CO2 by small boreal streams represents 77% of the total CO2 and 36% of the total organic carbon and total inorganic carbon exported by the streams from the catchments to the lakes. Knowledge of this important transfer and loss mechanism for CO2 will allow for more accurate modeling of boreal catchment C budgets. © 2010 by the American Geophysical Union.