Plant leaf tissue nitrogen and carbon content for samples collected under experimental warming or ambient conditions near Kangerlussuaq, Greenland, summer 2023

During the 2023 field season at a study site near Kangerlussuaq, Greenland, we collected multiple samples of three key caribou forage plants for chemical analysis. These included a graminoid (Poa pratensis), dwarf birch (Betula nana), and gray willow (Salix glauca). These samples were collected on multiple dates throughout the 2023 growing season for assessment of within season variation in plant leaf nitrogen content (%N by dry mass), carbon content (%C by dry mass), and carbon to nitrogen ratio (by dry mass, an index of forage quality). We also conducted a warming experiment using standardized protocols of the International Tundra Experiment to elevate near surface temperature on multiple plots from which Betula and Salix samples were collected at the end of the 2023 growing season. Our original plan included collecting graminoid (Poa) samples from experimentally-warmed plots as well, but unforeseen conditions at the field site, including unusual flooding of graminoid meadows, precluded such collections. Data on %N, %C, and C:N ratios of samples are provided here. All plant tissue samples were dried at 60C for at least 24 hours and submitted to the UC Davis Analytical Laboratory for ashing and determination of chemical content.