Soil water chemistry in acidic and non-acidic tundra, Toolik, Alaska (2022)

The motivation of this study was to show soil water chemistry across the thaw season in response to changing environmental conditions and site moisture and acidity. The research took place during the 2022 thaw seasons at two tundra hillslopes (acidic and non-acidic tundra) near Toolik Lake. Each study hillslope had three sites delineated across soil moisture conditions (dry, mesic, and wet), with three replicate 5 x 5 meter (m) plots at each site. In 2022, soil water was sampled from ponded surface water (0 centimeter [cm] depth) and from sippers installed at three depths (10 cm, 20 cm, and 40 cm) in each plot (n = 18). Sippers were constructed from hollow Teflon tubing with holes drilled along a ~5 cm interval on one end to allow water to flow in from the surrounding soil under vacuum generated by an attached syringe. Soil water was collected every week (nine samplings per area throughout the thaw season) and analyzed from pH, temperature, and specific conductance, as well as major element analyses, anion and nutrient analyses, dissolve organic carbon analyses, and dissolved ferrous iron.