Biosphere Atmosphere Transfer. Part C: Integrative Modelling of Fluxes

Abstract

roject phase. A highly qualified graduate student was finally found to work on this project: Christopher E. Sidle. He joined our research group in late October 1998. Principal results Within the region studied (Fig. 1) the total nitrogen input from the atmosphere to ecosystems is estimated to range between 22 and 51 kg of nitrogen per hectar per year. The results indicate that the critical loads of ecosystems sensitive to nitrogen inputs are exceeded by several kg of nitrogen per year. 13-42 kg of total annual deposition are deposited in gaseous form, 7-8 kg originate from precipitation (wet deposition), and roughly 2 kg are additional deposits of aerosol particles. Between 54% and 80% of total nitrogen deposition is reduced (NH x ) which is lost to the atmosphere from agricultural sources and losses from stables and manure storages. The greatest regional variation was found for dry deposition. In rural areas the deposition of reduced nitrogen dominates over oxidized forms (Fig. 1