Spatial and temporal assessment of soil nitrogen availability and relationships to biophysical variables in a high Arctic wetland
thesisposted on 2021-05-23, 13:43 authored by Jacqueline K.Y. Hung
Increased soil nutrient availability, and associated increase in ecosystem productivity, could create a negative feedback between Arctic ecosystem and the climate system, reducing the contribution of Arctic ecosystems to future climate change. This study explores the environmental controls over spatial patterns of soil nitrogen availability in a High Arctic wet sedge meadow and how they influence carbon exchange processes to predict whether this feedback will develop. Ion exchange resin membranes measured available inorganic nitrogen throughout the growing season at a high spatial resolution, while environmental variables and carbon flux measurements were taken at frequent intervals during the 2016 field season. Environmental measures correlated highly with total and late season nitrate with soil temperatures having the greatest effect. The results suggest that finer scale processes altering nitrogen availability may influence the C balance of wet sedge meadows in the High Arctic and how these ecosystems may respond to changes in climate.