Bioreactivity of Dissolved Organic Carbon in Ponds on Degrading Ice-Wedge Polygonal Terrain, Bylot Island, Nunavut, Canada (2017)

The ponds are located on a 3–5 m thick terrace resulting from the aggradation of Holocene deposits composed of peat mixed with aeolian sands and silts (syngenetic permafrost). The ponds were categorized based on their morphology and the degree of soil erosion linked to permafrost degradation: erosive ice-wedge trough (eIWT) ponds, stable ice-wedge trough (sIWT) ponds, and coalescent polygon (CP) ponds.

Water samples were collected approximately 20 centimeters below the surface, filtered using pre-combusted grade D glass fiber filters (2.7 µm nominal retention, Whatman), and incubated in the dark for 188 days at 15C°. To simulate nutrient-replete conditions, replicate incubation units were amended with sodium nitrate (NaNO3), ammonium chloride (NH4Cl), and monopotassium phosphate (KH2PO4), increasing ambient NO3-–NH4+ and PO43- concentrations by 80 and 10 µM, respectively.