Moss-associated Nitrogen (N2) fixation rate measurements from Toolik Field Station, Anchorage, and Fairbanks in 2016 and 2017

• Main Authors: Stuart, Julia, Mack, Michelle
• Format: Dataset
• Language: English
• Published: NSF Arctic Data Center 2020
• Subjects: N2 fixation; Alaska; bryophytes; boreal forest; Arctic tundra; Arctic; Fairbanks; Anchorage; Tundra
• Online Access: https://dx.doi.org/10.18739/a2qv3c475; https://arcticdata.io/catalog/view/doi:10.18739/A2QV3C475

During late June 2016, 10 sites were sampled near Fairbanks, Alaska and 4 sites sampled near Toolik Field Station, Alaska. The following year, in June 2017, an additional 10 sites were sampled in the Anchorage, Alaska area. Sites were selected for accessibility, lack of disturbance, and presence of moss. Each site was comprised of one 30 meters (m) transect and 6 subplots at 5 m intervals along the transect. Environmental variables of interest such as moisture, organic layer depth, active layer depth, pH, and tree density were measured for each site or subplot. Global positioning system points of location were used to extract altitude, mean annual temperature, and mean annual precipitation from Climate North America. Common and uncommon mosses were collected once in each subplot in which they appeared. Moss samples were cleaned and sorted into subsamples. One subsample was measured for 15Nitrogen (N2) natural abundance values. The other subsample was incubated in a closed syringe for 14 hours with 15N gas and then measured for the enriched 15N value. Paired samples were compared to calculate a rate of N fixation, in micrograms Nitrogen per gram dry moss per day. This dataset includes environmental data collected at each site/subplot as well as the d15N values and calculated N fixation rates associated with 35 distinct moss species across three geographic zones of Alaska, USA: Toolik Field Station, Fairbanks, and Anchorage.