Published In

Journal of Geophysical Research: Biogeosciences

Document Type

Post-Print

Publication Date

5-1-2017

Subjects

Carbon cycle (Biogeochemistry), Pond ecology, Water-atmosphere interaction -- Measurement, Carbon -- Environmental aspects

Abstract

Inland waters actively exchange gases with the atmosphere, and the gas exchange rate informs system biogeochemistry, ecology, and global carbon budgets. Gas exchange in medium- to large-sized lakes is largely regulated by wind; yet less is known about processes regulating gas transfer in small ponds where wind speeds are low. In this study, we determined the gas transfer velocity, k600, in four small ( < 250 m2 ) ponds by using a propane ( C3H8 ) gas injection. When estimated across 12 h periods, the average k600 ranged from 0.19 to 0.72 m d-1 across the ponds. We also estimated k600 at 2 to 3 h intervals during the day and evaluated the relationship with environmental conditions. The average daytime k600 ranged from 0.33 to 1.83 m d-1 across the ponds and was best predicted by wind speed and air or air-water temperature; however, the explanatory power was weak (R2 < 0.27) with high variability within and among ponds. To compare our results to larger water bodies, we compiled direct measurements of k600 from 67 ponds and lakes worldwide. Our k600 estimates were within the range of estimates for other small ponds, and variability in k600 increased with lake size. However, the majority of studies were conducted on medium-sized lakes (0.01 to 1 km2), leaving small ponds and large lakes understudied. Overall, this study adds four small ponds to the existing body of research on gas transfer velocities from inland waters and highlights uncertainty in k600, with implications for calculating metabolism and carbon emissions in inland waters.

Description

This is the peer reviewed version of the following article: Holgerson, M. A., Farr, E. R., & Raymond, P. A. (2017). Gas transfer velocities in small forested ponds. Journal of Geophysical Research: Biogeosciences, 122(5), 1011-1021., which has been published in final form at 10.1002/2016JG003734. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving

©2017 American Geophysical Union. All Rights Reserved.

DOI

10.1002/2016JG003734

Persistent Identifier

http://archives.pdx.edu/ds/psu/20663

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