Nitrogen cycling in tropical Atlantic Forest differing in exposure to urban atmospheric nitrogen deposition

摘要

Inorganic nitrogen (N)--ammonium (NH4 (+)-N) and nitrate (NO3 (-)-N)--deposition to tropical forests near urban areas frequently exceeds 5-10 kg ha(-1) yr(-1), surpassing critical loads for many forest types. We hypothesized that throughfall N fluxes to Atlantic Forest and effects on soil N cycling and availability would increase with proximity to a megacity (population 12 M) on Brazil's Atlantic Coast.