The effect of sampling effort on estimates of methane ebullition from peat

Ramirez, Jorge A.; Baird, Andy J.; Coulthard, Tom J.

Abstract

© 2017. American Geophysical Union. All Rights Reserved. We investigated the effect of sample size and sampling duration on methane bubble flux (ebullition) estimates from peat using a computer model. A field scale (10 m), seasonal ( > 100 days) simulation of ebullition from a two-dimensional (2-D) structurally varying peat profile was modeled at fine spatial resolution (1 mm × 1 mm). The spatial and temporal scale of this simulation was possible because of the computational efficiency of the reduced-complexity approach that was implemented, and patterns of simulated ebullition were consistent with those found in the field and laboratory. The simulated ebullition from the peat profile suggested that decreases in peat porosity—which cause increases in gas storage—produce ebullition that becomes increasingly patchy in space and erratic in time. By applying different amounts of spatial and temporal sampling effort, it was possible to determine the uncertainty in ebullition estimates from the peatland. The results suggest that traditional methods to measure ebullition can equally overestimate and underestimate flux by 20% and large ebullition events can lead to large overestimations of flux when sampling effort is low. Our findings support those of field studies, and we recommend that ebullition should be measured frequently (hourly to daily) and at many locations (n > 14).

Citation

Ramirez, J. A., Baird, A. J., & Coulthard, T. J. (2017). The effect of sampling effort on estimates of methane ebullition from peat. Water Resources Research, 53(5), 4158-4168. https://doi.org/10.1002/2017wr020428

• Journal Article Type: Article
• Acceptance Date: May 1, 2017
• Online Publication Date: May 22, 2017
• Publication Date: Jun 17, 2017
• Deposit Date: May 16, 2017
• Publicly Available Date: May 22, 2017
• Journal: Water resources research
• Print ISSN: 0043-1397
• Electronic ISSN: 1944-7973
• Publisher: American Geophysical Union
• Peer Reviewed: Peer Reviewed
• Volume: 53
• Issue: 5
• Pages: 4158-4168
• DOI: https://doi.org/10.1002/2017wr020428
• Keywords: Peatland; Methane ebullition; Sampling effort; Porosity
• Public URL: https://hull-repository.worktribe.com/output/451426
• Publisher URL: http://onlinelibrary.wiley.com/doi/10.1002/2017WR020428/abstract
• Additional Information: Copy of article: Ramirez, J. A., A. J. Baird, and T. J. Coulthard (2017), The effect of sampling effort on estimates of methane ebullition from peat, Water Resour. Res., 53, 4158–4168, doi:10.1002/2017WR020428.