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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Hydrology and Remote Sensing Laboratory » Research » Publications at this Location » Publication #415108
Research Project: From Field to Watershed: Enhancing Water Quality and Management in Agroecosystems through Remote Sensing, Ground Measurements, and Integrative Modeling

Location: Hydrology and Remote Sensing Laboratory

Title: Diel greenhouse gas emissions demonstrate a strong response to vegetation patch types in a freshwater wetland

Author
item TAYLOR, K - University Of Maryland
item SHARP, S - University Of Maryland
item STEWART, G - University Of Maryland
item WILLIAMS, M - University Of Maryland
item McCarty, Gregory
item PALMER, M - University Of Maryland

Submitted to: Journal of Geophysical Research-Biogeosciences
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/24/2024
Publication Date: 11/1/2024
Citation: Taylor, K.J., Sharp, S.J., Stewart, G.A., Williams, M.R., Mccarty, G.W., Palmer, M.A. 2024. Diel greenhouse gas emissions demonstrate a strong response to vegetation patch types in a freshwater wetland. Journal of Geophysical Research-Biogeosciences. 129(11). https://doi.org/10.1029/2024JG008193.
DOI: https://doi.org/10.1029/2024JG008193

Interpretive Summary: Methane (CH4) emissions from wetlands are known to vary over space and time, be largely controlled by vegetation, and exhibit strong seasonal patterns. Yet daily patterns are not well characterized due to the limited number of studies and to difficulties in obtaining nighttime measurements. To address this, we investigated CH4 flux patterns over day and night cycles in patches characterized by emergent, submerged, or no vegetation in a temperate, freshwater, herbaceous wetland. We show that daily patterns of CH4 emissions are strongly linked to the type of vegetation present but the mechanistic influence of plants on production and consumption is unclear. This work contributes to the growing understanding of how CH4 varies within wetland landscapes over time.

Technical Abstract: Wetland methane (CH4) fluxes are highly variable over spatial and temporal scales due to variations CH4 production, oxidation, and transport. While some aspects of temporal variability in CH4 fluxes are well documented, diel variability is poorly constrained and studies report conflicting findings making it difficult to generalize. Variations in topography, soil chemistry, hydrologic regime, and vegetation types can result in characteristically different “patches” that likely influence differences in diel patterns. We investigated diel patterns of CH4 fluxes from a large, seasonal-mineral soil wetland in Maryland (USA) across three functionally unique patches: two with vegetation (emergent and submerged aquatic vegetation), and one without (open water) during the summer of 2021. To explore relationships between vegetation, environmental conditions, and flux patterns, we also measured physicochemical variables (air and water temperature, pH, relative humidity, PAR, dissolved oxygen, water depth). To our knowledge, this is the first study comparing diel variability across such patch types. We found that diel patterns were strongly linked to patch types. These differences could be a direct result of vegetation impact on the production, oxidation and/or transport of CH4 or on conditions covarying with patch type. Vegetation whose functions facilitate both production and oxidation of CH4 can make diel patterns in these patches especially hard to predict. This study contributes to the growing understanding of how CH4 fluxes vary spatially over diel cycles and emphasizes the importance of taking spatially varying diel patterns into account when estimating fluxes.