Nutrient availability, greenhouse gas fluxes, and environmental variables across burn treatments in the Yukon-Kuskokwim Delta, 2022-2023

The Yukon-Kuskokwim Delta (YKD) in southwestern Alaska in the discontinuous permafrost region is undergoing rapid change as a result of climate warming and disturbance. This area is made up upland peat plateau tundra interspersed with patchwork steams, fens, ponds, and lakes. In 2015, a tundra wildfire burned more than 541.54 square kilometers (km2) in the YKD, which is one of the larger tundra fires recorded in the area. This region has a wildfire history dating back to the last century. Researchers at the Woodwell Climate Research Center have been working in this region conducting terrestrial and aquatic studies to determine wildfire and permafrost thaw effects on carbon and nutrient cycling and vegetation change. These datasets were collected from the Izaviknek Uplands of the Yukon-Kuskokwim Delta during the growing seasons of 2022 and 2023. Ten 30-meter transects, each with 3 plots spaced out by 10-meters, were established across unburned tundra, the Izaviknek River fire scar (2015 wildfire), and Smitty fire scar (1972 wildfire), where co-located environmental variables (soil temperature, soil moisture, active layer depth), inorganic nitrogen availability (ammonium and nitrate), and greenhouse gas fluxes (carbon dioxide, methane, and nitrous oxide) were measured.