The Nitrogen Budget of Thoreau's Bog

Publisher Website
Google Scholar
Abstract
Dinitrogen fixation and atmospheric deposition are the dominant sources of nitrogen to Thoreau's Bog, contributing °1.0 and 0.7 g·m—2°yr—1, respectively. Denitrification must compete with nitrate uptake and the reduction of NO3— to NH4+; the latter process accounts for the fate of °25% of nitrate input to the bog. Gaseous ammonia is not an input, but appears to be lost in small amounts from the bog surface. Organic N is deposited into the peat by plants at an annual rate of almost mg/m2. About a third of this amount is "permanently" deposited, and the balance is recycled through mineralization and uptake. Compared to other ecosystems, the bog processes nitrogen in a parsimonious fashion. Annual fluxes are small compared to total N stored in the ecosystem, and nearly 80% of annual N input is retained with the system.