The contribution of various microbial processes to nitrogen cycling in terrestrial and aquatic ecosystems is poorly understood. Most studies concentrate on two major processes of denitrification and nitrification, but currently there is also a growing attention for other microbial N-transformations like co-denitrification, nitrifier-denitrification, nitrate ammonification (DNRA) or anerobic ammonia oxidation (ANAMMOX).
Emissions of gaseous N species due to microbial transformations in soils, aquifers and surface waters are of importance to ecosystem N budgets as well as to global warming scenarios and stratospheric ozone degradation.
Quantification of gaseous N exchange rates is a great analytical challenge because of high ambient backgrounds and quantitatively small mass fluxes. Similarly, the distinction between various microbial pathways contributing to N2O emissions is still ambiguous, but crucial for development of effective mitigation strategies. Since dynamics of microbial processes have mostly been investigated under laboratory conditions, their effective control at the field scale and the spatial variability is still not sufficiently clarified. We invite contributions from the following fields:
Methodical advances in measuring and modelling of microbial N-transformation processes in soils, wetlands, aquifers and open water bodies; measuring N2 and N2O fluxes and investigating controlling factors under field-like conditions using methods like incubation under He atmosphere, 15N-Tracer technique, natural abundance stable isotopes signatures or N2/Ar ratios; innovative methods on controlling factors; method comparisons; process-based modelling at various scales; microbial community structures; molecular techniques.