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A collection of carbon dioxide (CO2), methane (CH4) gas flux and leaf area index (LAI) datasets from a temperate salt-marsh with S. alternifloria vegetation cover (39.09 ˚N, 75.44 ˚W). Measurements were collected from May 2020 through December of 2020 with 2 separate collection times per month for a total of 16 field sampling campaigns. Measurements were performed on 5 plots located within the footprint of an eddy covariance tower which collects ecosystem scale CO2 and CH4 fluxes (Ameriflux Site ID: StJ). Supporting measurements were also performed for leaf-level photosynthesis rates and plot LAI during each chamber campaign. </p> </p> The dark and light flux chambers each occupied 1.0 m2 ground area and the vegetation stand was fully enclosed by the chambers. The sediment chambers each occupied 0.025 m2 ground area and the vegetation stand was excluded from the chambers. CO2 and CH4 fluxes from all chambers were measured with a portable greenhouse gas analyzer (LGR Los Gatos Research, Model 915-0011, San Jose, CA) for approximately 2-3 min after chamber closure. The dark and soil chambers were 100% opaque while the light chamber allowed for 90% transmission of photosynthetically active radiation. Sediment fluxes and leaf-level photosynthesis was measured from 2 points within each of the larger chamber plots. Leaf-level photosynthesis was measured with a portable photosynthesis meter (Li-6400, Licor, Lincoln, NE) and LAI was measured with a ceptometer (Accupar LP80, Meter Inc, Pullman, WA, USA). All measurements were made consecutively over the span of 2-3 hours with leaf-level measurements preformed first, followed by light chambers, dark chambers, sediment chambers and plot LAI. </p> </p> </p>
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Carbon-13 (13C) methane from an isotopic labelling experiment in Arctic tundra, Utqiagvik, Alaska, 2019.
An isotopic labeling experiment was conducted in an Arctic coastal wet tundra ecosystem to determine how quickly acetate is transformed into methane and transported from the soil to the atmosphere. Carbon-13 (13C) labelled acetate was injected into soil chambers installed across a 131 meter (m) transect. Gas samples were periodically collected from the headspace in chambers, and analyzed for methane concentration and enrichment in 13C. Methane flux was roughly estimated from the final concentration in the chambers accumulated over a one-hour sampling period. This dataset includes methane fluxes, concentrations and 13C enrichment values from this experiment. In addition, water samples were collected from 15 centimeters (cm) depth after the final time point for measurements of residual dissolved 13C-methane in the soil after 9 days.
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- Award ID(s):
- 1702797
- PAR ID:
- 10310648
- Publisher / Repository:
- NSF Arctic Data Center
- Date Published:
- Subject(s) / Keyword(s):
- acetate methane
- Format(s):
- Medium: X Other: text/xml
- Sponsoring Org:
- National Science Foundation
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