Alberta Bog Net Nitrogen Mineralization, 2013-2015

Alberta bogs are subject to periodic wildfire. Although these bogs
have persisted under low atmospheric nitrogen deposition (less than 2
kg N/ha/yr), nitrogen deposition in northern Alberta is increasing due
to ongoing oil sands development. This study examined how time since
fire and experimental N deposition affects nitrogen mineralization in
near-surface bog peat. Net nitrogen mineralization (ammonification,
nitrification, dissolved organic N production) was quantified using
the buried bag technique in 5 Alberta bogs differing in time since
fire. At each site, 24 2.4 _ 4.8 m plots were established, with 6
replicate plots receiving one of four N addition treatments: controls
(receiving no water or N), H2O controls (receiving water, but no N; 0
kg N ha-1 yr-1), and 10 and 20 kg N ha-1 yr-1, applied as NH4NO3
dissolved in 15 L of H2O and applied via backpack sprayer eight times
during each summer field season. We established plots and began N
additions in 2011 at the Utikuma Bog site and in 2013 for the other
four sites. This study is published as: Stuart JEM, Wieder RK, Vile MA
(2018) Net Nitrogen Mineralization in Alberta Bog Peat is Insensitive
to Experimentally Increased Nitrogen Deposition and Time Since
Wildfire. Biogeochemistry, in press.