Deposition nitrogen

In heavily polluted areas, such as The Netherlands, the nitrogen deposition is so large that the N-uptake is comparably small. In such areas, throughfall can be used to quantify the total deposition. In normally polluted areas, the inorganic nitrogen flux in throughfall will to some extent be an underestimate of the atmospheric deposition. 

Stem flow is important for deciduous stands and young coniferous stands. Total stand precipitation might be underestimated by up to 30% in such sites when stem flow is not taken into account. In beech stands, the stem flow makes up a considerable part of the total deposition. 

Forests are efficient filters of dust. Dust influences photosynthesis and transpiration, and in part it also corrodes the plant surface. An accumulation of dust takes place near the emittent as well as in forests of higher altitudes after transport. 

Deposition rates of locally generated dust, which is rich in calcium and magnesium, are high in the Limestone Alps of Austria. Alkaline dust particles have the size range of 1 to 20 xm. Dusts containing lime react as alkaline. 

Larger parts of the heavy metal emission of smelters and power plants are deposited in the vicinity (up to 10 km distance) of the emitters. Pb is deposited after long-range transport of fine dust in forests of higher altitudes of the mountain area up to 0.5 kg ha 2T. In Germany, Pb deposition has been decreasing since 1974, mainly due to reduction of the Pb content in petrol (Ulrich 1991). 

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Impacts of Nitrogen Deposition on Terrestrial Ecosystems, Report of the United Kingdom Review Group on Impacts of Atmospheric Nitrogen, Department of the Environment, London, 1994. Report of the AERC Institute of Arable Crops Research for 1991, AERC, London, 1992, p. 36. 

Assessing the spatial distribution of NHj emissions is of particular interest because of the link with ecological impacts of nitrogen deposition. Using statistical atmospheric transport models, such emission maps may be used to... 

INDITE, Impacts of Nitrogen Deposition in Terrestrial Ecosystems in the United Kingdom,... 

Schindler, D. W. and Bayley, S. E. (1993). The biosphere as an increasing sink for atmospheric carbon Estimates from increased nitrogen deposition. Global Biogeochem. Cycles 7,717-733. 

This surface had an Auger spectrum similar to that of the surface produced during the reaction and exhibited a catalytic activity similar to that of the clean surface. This suggests that during the reaction the amount of nitrogen deposited on the surface is close to that present in the compound PeN and possibly that this is actually present at the surface during the reaction (6). 

FIG. 17. Schemaiics of Ihe process involved in the interaction of C and N species incident upon a carbon-nitrogen deposit. (Reproduced from [72].)... 

S.J. Langan (ed.) The Impact of Nitrogen Deposition on Natural and Semi-Natural... 

Yano Y, McDowell WH, Aber JD (2000) Biodegradable dissolved organic carbon in forest soil solution and effects of chronic nitrogen deposition. Soil Biol Biochem 32 1743-1751... 

Johnson D, Leake JR, Lee JA (1999) The effects of quantity and duration of simulated pollutant nitrogen deposition on root-surface phosphatase activities in calcareous and acid grasslands a bioassay approach. New Phytol 141 433 142. doi http //www.blackwell-synergy.com/doi/ abs/10.1046/j. 1469-8137.1999.00360.x... 

Goulding KWT, Bailoy NJ, Bradbury NJ, Hargreaves P, Howe M, Murphy DV, Poulton PR, Willison TW (1998) Nitrogen deposition and its contribution to nitrogen cycling and associated processes. New Phytol 139 49-58... 

Kristensen HL, Gundersen P, Callesen I, Reinds GJ (2004) Throughfall nitrogen deposition has different impacts on soil solution nitrate concentration in European coniferous and deciduous forests. Ecosystems 7 180-192... 

Excess nitrogen deposition contributes not only to acidification, but can also lead to the eutrophication of soils and surface waters. 

Figure 4. Top The percentage of ecosystem area protected (i.e., non-exceedance of critical loads) from acidifying deposition of sulfur and nitrogen in 1990 (left) and in the year 2010 according to current emission reduction plans in Europe (right). Bottom The accumulated average exceedance (AAE) of the acidity critical loads by sulfur and nitrogen deposition in 1990(left) and 2010 (right). Sulfur deposition data were provided by the FMEP/MSC-W (Posch etal., 1999).

Spatial patterns of atmospheric nitrogen deposition in (a) 1860, (b) early 1990s, and (c) 2050. Source-. After Galloway, J. N., et al. (2004). Biogeochemistry 70, 153-226. (See companion website for color version.)... 

Data for wet deposition of nitrogen compounds, however, are not comparable to those for sulfates. Measurements at the same three locations reveal that nitrogen deposition decreased by only 5 and 4 percent, respectively, in the first two regions, and actually increased by 11 percent in the third. Overall trends throughout the eastern United States indicate a reduction in nitrogen wet deposition of only 2 percent. 

Similar trends were detected in a more limited study conducted by the Adirondack Lakes Survey Commission during the 1990s. The commission found a reduction of 92 percent in sulfate deposition in a selected sample of lakes in the Adirondack Mountains between 1992 and 1999, but an increase of 48 percent in nitrogen deposition in the same lakes. 

Historically, nitrogen deposition has not been considered a serious threat to the integrity of aquatic systems. Most terrestrial systems have been assumed to retain N strongly. In such cases there is a small probability that deposited N would make its way to the surface waters that drain these terrestrial systems. Nitrogen within aquatic ecosystems can arise from a... 

Table I. Rates of Nitrogen Deposition in Several Areas of North America...

Atmospheric N can enter aquatic systems either as direct deposition to water surfaces or as N deposition to the terrestrial portions of a watershed. Nitrogen deposited to the watershed is routed and transformed by watershed processes. It may eventually reach aquatic systems in forms only indirectly related to the original deposition. The transformations that N undergoes within the watershed (e.g., in soils, by microbial action, and in plants) play a major role in determining what forms and amounts of N eventually reach surface waters. Much of the challenge of determining when N deposition is... 

Links Between Nitrogen Loss and Nitrogen Deposition... 

Fig. 12 High-resolution assessment of atmospheric nitrogen deposition in Denmark accounting for emissions from single farms. Figure obtained from Geels et al. [80]...

Hertel O, Skj0th CA, L0fstr0m P, Geels C, Frohn LM, Ellermann T, Madsen PV (2006) Modelling nitrogen deposition on a local scale - a review of the current state of the art. Environ Chem 3 317-337... 

Bobbink R, Hicks K, Galloway J, Spranger T, Alkemade R, Ashmore M, Bustamante M, Cinderby S, Davidson E, Dentener F, Emmett B, Erisman JW, Fenn M, Gilliam F, Nordin A, Pardo L, de Vries W (2010) Global assessment of nitrogen deposition effects on terrestrial plant diversity a synthesis. Ecol Appl 20 30-59... 

Stevens CJ, Dise NB, Mountford JO, Gowing DJ (2004) Impact of nitrogen deposition on the species richness of grasslands. Science 303 1876—1879... 

Stevens CJ, Dupre C, Dorland E, Gaudnik C, Gowing DJG, Bleeker A, Diekmann M, Alard D, Bobbink R, Fowler D, Corcket E, Mountford JO, Vandvik V, Aarrestad PA, Muller S, Dise NB (2010) Nitrogen deposition threatens species richness of grasslands across Europe. Environ Pollut 158 2940-2945... 

Hertel O, Geels C, Frohn LM, Ellermann T, Skjoth CA, Lofstrom P, Christensen JH, Andersen, HV, Peel RG (2012) Assessing atmospheric nitrogen deposition to natural and semi-natural ecosystems experience from Danish studies using the DAMOS system. Atmos Environ, in press, http //dx.doi.Org/10.1016/j.atmosenv.2012.02.071... 

Dore AJ, Kryza M, Hall JR, Hallsworth S, Keller VJD, Vieno M, Sutton MA (2012) The influence of model grid resolution on estimation of national scale nitrogen deposition and exceedance of critical loads. Biogeosciences 9 1597-1609... 

Cape JN, Tang YS, van Dijk N, Love L, Sutton MA, Palmer SCF (2004) Concentrations of ammonia and nitrogen dioxide at roadside verges, and their contribution to nitrogen deposition. Environ Pollut 132 469 -78... 

Zhang Y, Dore AJ, Liu X, Zhang F (2011) Simulation of nitrogen deposition in the North China Plain by the FRAME model. Biogeosciences 8 3319-3329... 

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