Professor David Biesboer, former director of the Itasca Biological Station, conducted research on nitrogen cycling at Iron Springs Bog. In 2000, Biesboer demonstrated that nitrogen fixation rates in Iron Springs Bog were very low, ranging from 0.43 μmol N fixed/m2/day to 1.20 μmol N fixed/m2/day. Because the bog has very low rates of nitrification, it also had no detectable signs of denitrification occurring. These low rates of nitrogen cycling processes in the bog likely stem from the low concentrations of nitrites and nitrates in the groundwater that feeds it and low rates of nitrification, mineralization, and ammonification. In a follow-up study in 2002, Biesboer examined the fluxes of nitrogen in Iron Springs Bog. This work determined that the primary source of nitrogen in the bog is from atmospheric deposition, accounting for 66% of nitrogen input. Atmospheric deposition is followed by fixation (19%), mineralization (12%), and surface water (3%). Biesboer hypothesized that most nitrogen fixation in the bog takes place in the Sphagnum layer since it dominates the understory. The high proportion of nitrogen input from atmospheric deposition could prove problematic because it can lead to surface water acidification and disturbances in nitrogen cycling in the bog. However, research has yet to determine the effects of high atmospheric nitrogen deposition in Iron Springs Bog.
