Advances in understanding, models and parameterizations of biosphere-atmosphere ammonia exchange
Journal article, 2013

Atmospheric ammonia (NH3) dominates global emissions of total reactive nitrogen (N-r), while emissions from agricultural production systems contribute about two-thirds of global NH3 emissions; the remaining third emanates from oceans, natural vegetation, humans, wild animals and biomass burning. On land, NH3 emitted from the various sources eventually returns to the biosphere by dry deposition to sink areas, predominantly semi-natural vegetation, and by wet and dry deposition as ammonium (NH4+) to all surfaces. However, the land/atmosphere exchange of gaseous NH3 is in fact bi-directional over unfertilized as well as fertilized ecosystems, with periods and areas of emission and deposition alternating in time (diurnal, seasonal) and space (patchwork landscapes). The exchange is controlled by a range of environmental factors, including meteorology, surface layer turbulence, thermodynamics, air and surface heterogeneous-phase chemistry, canopy geometry, plant development stage, leaf age, organic matter decomposition, soil microbial turnover, and, in agricultural systems, by fertilizer application rate, fertilizer type, soil type, crop type, and agricultural management practices. We review the range of processes controlling NH3 emission and uptake in the different parts of the soil-canopy-atmosphere continuum, with NH3 emission potentials defined at the substrate and leaf levels by different [NH4+] / [H+] ratios (0).

MICROMETEOROLOGICAL FLUX MEASUREMENTS

FERTILIZED CUT GRASSLAND

GASEOUS DRY DEPOSITION

AIR-QUALITY MODELS

GRAMINAE INTEGRATED EXPERIMENT

STOMATAL COMPENSATION POINT

GAS-PARTICLE INTERACTIONS

RELAXED EDDY ACCUMULATION

REACTIVE NITROGEN-COMPOUNDS

INTENSIVELY MANAGED GRASSLAND

Author

C. R. Flechard

R.-S. Massad

B. Loubet

E. Personne

David Simpson

Chalmers, Earth and Space Sciences, Global Environmental Measurements and Modelling

J. O. Bash

E. J. Cooter

E. Nemitz

M. A. Sutton

Biogeosciences

1726-4170 (ISSN) 1726-4189 (eISSN)

Vol. 10 7 5183-5225

Driving Forces

Sustainable development

Roots

Basic sciences

Subject Categories

Earth and Related Environmental Sciences

DOI

10.5194/bg-10-5183-2013

More information

Created

10/6/2017