Dataset: Bulk sediment organic matter composition
Deployment: Plum_Island

The three ponds are located in the high marsh (1.43-1.46 m above North American Vertical Datum of 1988) of the Plum Island Ecosystems – Long Term Ecological Research (PIE-LTER) site. Surface sediments were collected weekly for TOC, TN, δ¹³C, and δ¹⁵N (June 25-August 13 and November 11-25, 2014). Cores (5 cm diameter x 2 cm deep) were collected from three 1 m² quadrats placed at random locations along two crisscrossing transects in each pond. Sediments were combined in combusted glass vials to form composite samples and stored (-80 ℃) until analysis. sediment samples were prepared for elemental and isotopic analyses by drying to constant mass (60 °C), homogenizing with a Retsch Mixer Mill 200 (plants and sediments), and fuming with hydrochloric (HCl) acid to remove carbonates (Hedges and Stern 1984). Analyses were performed by the Stable Isotope Laboratory at the Marine Biological Laboratory (Woods Hole, MA). Isotopic data are reported in the conventional δ-notation in units of per mil (‰).