Not logged in
PANGAEA.
Data Publisher for Earth & Environmental Science

Fuchs, Matthias; Jones, Miriam C; Gowan, Evan J; Frolking, Steve; Walter Anthony, Katey M; Grosse, Guido; Jones, Benjamin M; O'Donnel, Jonathan; Brosius, Laura Susan; Treat, Claire C: Methane flux measurements from coastal wetlands on the Kenai Peninsula [dataset]. PANGAEA, https://doi.pangaea.de/10.1594/PANGAEA.960156 (dataset in review)

Show MapGoogle Earth

Abstract:
The methane (CH4) flux was measured during a field campaign in August 2021 on the Kenai Peninsula, Alaska. We chose locations in coastal wetlands along transects to cover a gradient from freshwater flooded into tidal, saltwater flooded wetlands. In total, we measured at 27 different locations including saltwater tidal regularly flooded bare grounds, temporarily irregularly flooded, as well as seasonally flooded, vegetated coastal wetlands.
Flux measurements were made with a micro-portable LosGatos greenhouse gas analyzer (LosGatos Research) and a light-weight custom-made bucket chamber consisting of non-transparent PVC (diameter = 26 cm, volume ~ 19,000 cm3). We chose this small, lightweight equipment in order to be highly mobile in muddy, shrubby terrain and measure at field sites which were not easy to access. At each site we measured three replicates for 7 to 10 minutes, described the vegetation cover (if present), and measured the chamber and air temperature. The bucket chamber was equipped with a venting tube and a small fan to have well-mixed conditions in the chamber.
The CH4 flux (in mg CH4 m-2 h-1) for each replicate measurement was calculated based on the volume and temperature of the bucket chamber, and the ideal gas law. We manually removed the first 30 sec of each measurement, because of potential disturbance while placing the bucket chamber on the site (we did not use pre-installed collars). Fluxes were calculated by applying a linear regression to the CH4 concentration and were given in mg CH4 m-2 h-1. The r squared was used to determine the quality of the linear regression. Fluxes that had a linear regression with a r squared below 0.9 were discarded. However, we did not want to exclude all the near-zero measurements as these indicate important data as well (no CH4 fluxes). Therefore, all measurements, which were below the precision of the greenhouse gas analyzer of 0.5 ppb (~0.44 mg CH4 m-2 h-1, depending on chamber volume) were included in the analysis as zero fluxes.
In a final step, we averaged all the replicates from a measurement site in order to have one CH4 flux value per measurement site and calculated the CH4 flux for the growing season of 153 days in g CH4 m-2 yr-1, which served as input data for the bootstrapping of the Beringia coastal wetland CH4 estimation.
Keyword(s):
chamber measurements; Flux; Kenai; Methane
Supplement to:
Fuchs, Matthias; et al. (in review): Methane flux from Beringian coastal wetlands for the past 20,000 years.
Project(s):
The role of non-growing season processes in the methane and nitrous oxide budgets in pristine northern ecosystems (FluxWIN)
Funding:
European Research Council (ERC), grant/award no. 851181: The role of non-growing season processes in the methane and nitrous oxide budgets in pristine northern ecosystems
National Science Foundation (NSF), grant/award no. 1903623: Collaborative Research: Sea-level rise, coastal wetland expansion, and proglacial lake contributions to abrupt increases in northern atmospheric CH4 during the last deglaciation
National Science Foundation (NSF), grant/award no. 1903735: Collaborative Research: Sea-level rise, coastal wetland expansion, and proglacial lake contributions to abrupt increases in northern atmospheric CH4 during the last deglaciation
National Science Foundation (NSF), grant/award no. 1927553: Collaborative Research: AccelNet: Permafrost Coastal Systems Network (PerCS-Net) -- A Circumpolar Alliance for Arctic Coastal Community Information Exchange
Coverage:
Median Latitude: 60.537113 * Median Longitude: -151.215966 * South-bound Latitude: 60.523670 * West-bound Longitude: -151.266890 * North-bound Latitude: 60.546660 * East-bound Longitude: -151.186070
Date/Time Start: 2021-08-04T00:00:00 * Date/Time End: 2021-08-24T00:00:00
Event(s):
AK-Land_2021_SAlaska_KEN21-T1-1 (KEN21-T1-1) * Latitude: 60.523670 * Longitude: -151.191500 * Location: Kenai River, Alaska * Campaign: AK-Land_2021_SAlaska (Perma-X Land 2021) * Basis: AWI Arctic Land Expedition * Method/Device: Greenhouse Gas Analyzer, LosGatos
AK-Land_2021_SAlaska_KEN21-T1-2 (KEN21-T1-2) * Latitude: 60.525890 * Longitude: -151.190730 * Location: Kenai River, Alaska * Campaign: AK-Land_2021_SAlaska (Perma-X Land 2021) * Basis: AWI Arctic Land Expedition * Method/Device: Greenhouse Gas Analyzer, LosGatos
AK-Land_2021_SAlaska_KEN21-T1-3 (KEN21-T1-3) * Latitude: 60.528100 * Longitude: -151.189870 * Location: Kenai River, Alaska * Campaign: AK-Land_2021_SAlaska (Perma-X Land 2021) * Basis: AWI Arctic Land Expedition * Method/Device: Greenhouse Gas Analyzer, LosGatos
Parameter(s):
#NameShort NameUnitPrincipal InvestigatorMethod/DeviceComment
1Event labelEventFuchs, Matthias
2Area/localityAreaFuchs, Matthias
3LocationLocationFuchs, Matthias
4TransectTransectFuchs, Matthias
5SiteSiteFuchs, Matthias
6ReplicateReplFuchs, Matthias
7DATE/TIMEDate/TimeFuchs, MatthiasGeocode – Measurement Date
8TypeTypeFuchs, MatthiasWetland
9ClassClassFuchs, MatthiasWetland Class
10Analytical methodMethodFuchs, MatthiasMeasuring method
11Major vegetationMajor vegetationFuchs, MatthiasDominant Vegetation
12VolumeVolcm3Fuchs, MatthiasChamber Volume
13AreaAream2Fuchs, MatthiasChamber Area
14Temperature, technicalT tech°CFuchs, MatthiasChamber temperature
15Methane, fluxCH4 fluxmg/m2/hFuchs, MatthiasGreenhouse Gas Analyzer, LosGatos
16Coefficient of determinationR**2Fuchs, Matthias
17Methane, flux, limit of detectionCH4 flux LODmg/m2/hFuchs, Matthias
18CommentCommentFuchs, Matthias
License:
Creative Commons Attribution 4.0 International (CC-BY-4.0) (License comes into effect after moratorium ends)
Status:
Curation Level: Enhanced curation (CurationLevelC) * Processing Level: PANGAEA data processing level 3 (ProcLevel3)
Size:
2061 data points

Download Data

Download dataset as tab-delimited text — use the following character encoding:

View dataset as HTML (shows only first 2000 rows)