Atmospheric Deposition Of Nitrogen Compounds Research Articles

Influence of Deposition of Atmospheric Nitrogen Compounds to the Surface Chlorophyll-a Concentration over Japan Sea

Influence of Deposition of Atmospheric Nitrogen Compounds to the Surface Chlorophyll-a Concentration over Japan Sea

The impact of atmospheric acid deposition on tree growth and forest understory vegetation in the Athabasca Oil Sands Region

Atmospheric acid deposition is of major concern in the Athabasca Oil Sands Region (AOSR) in northern Alberta, Canada, which is home to the third largest oil reserve in the world. After decades of oil sands production in the AOSR, the potential impact of deposition on forest health, including tree growth and understory biodiversity, is still not clear. We evaluated the relationship of modelled/interpolate atmospheric deposition of nitrogen (N), sulphur (S), base cations (BC), and derived potential acid input (PAI) from surface oil sands mining with: (1) the radial growth (i.e. basal area increment; BAI) of jack pine (Pinus banksiana Lamb.) trees using data from two decadal time periods, prior to (1957–1966) and during (2001−2010) active oil sands development in the AOSR; and (2) forest understory vegetation (abundance, diversity, and composition), which is an important component of forest biodiversity. BAI of jack pine trees varied with N, S, and BC deposition between the two time periods, and with the direction of the site relative to main emission sources. Growth was higher in areas close to the oil sands surface mining operations prior to and after oil sands development. BAI was also positively related to atmospheric deposition in the recent period, but these relationships were weaker in the active period versus the non-active period. Understory vegetation – including vascular plant cover, richness, and diversity – increased in relation to modelled atmospheric N and S deposition. There was limited correlation between soil pH or the BC:Al ratio (indicators of soil acidification) and BAI and understory vegetation responses. No evidence was found for detrimental effects of atmospheric emissions (and subsequent deposition) from oil sands production on tree growth or forest understory vegetation. The results, if anything, suggest a fertilization effect due to enhanced atmospheric deposition of nitrogen compounds.

Efficacy of passive sampler collection for atmospheric NO2 isotopes under simulated environmental conditions.

Nitrogen oxides or NOx (NOx = NO + NO2 ) play an important role in air quality, atmospheric chemistry, and climate. The isotopic compositions of anthropogenic and natural NO2 sources are wide-ranging, and they can be used to constrain sources of ambient NO2 and associated atmospheric deposition of nitrogen compounds. While passive sample collection of NO2 isotopes has been used in field studies to determine NOx source influences on atmospheric deposition, this approach has not been evaluated for accuracy or precision under different environmental conditions. The efficacy of NO2 passive sampler collection for NO2 isotopes was evaluated under varied temperature and relative humidity (RH) conditions in a dynamic flux chamber. The precision and accuracy of the filter NO2 collection as nitrite (NO2- ) for isotopic analysis were determined using a reference NO2 gas tank and through inter-calibration with a modified EPA Method 7. The bacterial denitrifer method was used to convert 20 μM of collected NO2- or nitrate (NO3- ) into N2 O and was carried out on an Isoprime continuous flow isotope ratio mass spectrometer. δ15 N-NO2 values determined from passive NO2 collection, in conditions of 11-34 °C, 1-78% RH, have an overall accuracy and precision of ±2.1 ‰, and individual run precision of ±0.6 ‰. δ18 O-NO2 values obtained from passive NO2 sampler collection, under the same conditions, have an overall precision of ± 1.3 ‰. Suitable conditions for passive sampler collection of NO2 isotopes are in environments ranging from 11 to 34 °C and 1 to 78% RH. The passive NO2 isotope measurement technique provides an accurate method to determine variations in atmospheric δ15 N-NO2 values and a precise method for determining atmospheric δ18 O-NO2 values. The ability to measure NO2 isotopes over spatial gradients at the same temporal resolution provides a unique perspective on the extent and seasonality of fluctuations in atmospheric NO2 isotopic compositions. Copyright © 2017 John Wiley & Sons, Ltd.

Eutrophication trends in forest soils in Galicia (NW Spain) caused by the atmospheric deposition of nitrogen compounds

We calculated the sensitivity of Galician forest soils to eutrophication caused by atmospheric deposition of nitrogen compounds, using the Simple Mass Balance (SMB) method as described by [Posch, M., de Vries, W., Hettelingh, J.-P., 1995. Critical loads of sulphur and nitrogen. In: Posch, M., de Smet, P.A.M., Hettelingh, J.-P., Downing, R.J. Calculation and Mapping of Critical Thresholds in Europe. Status Report 1995, Coordination Center for Effects, National Institute for Public Health and the Environment, Bilthoven, The Netherlands, pp. 31–42]. Deposition values were used to calculate critical loads exceedance. Galician natural forest ecosystems can support nitrogen deposition loads of more than 10 kg N ha −1 yr −1. The lowest critical loads (approximately 10 kg N ha −1 yr −1) mainly occurred in forest stands in the interior zone, while highest critical load values (approximately 68 kg N ha −1 yr −1) were observed in eucalyptus stands at low altitudes in the littoral area. Exceedances based on N deposition levels, calculated from data recorded in 2001, occurred in 40% of the forest soils, showing the need to control N emissions in these areas to prevent possible eutrophication of soils and waters. Analysis of rainfall bulk composition revealed that ammonium, probably derived from agricultural and cattle activities, was the main compound responsible for N deposition in Galicia.

Atmospheric input of nitrogen into the North Sea: ANICE project overview

The aim of the atmospheric nitrogen inputs into the coastal ecosystem (ANICE) project is to improve transport–chemistry models that estimate nitrogen deposition to the sea. To achieve this, experimental and modelling work is being conducted which aims to improve understanding of the processes involved in the chemical transformation, transport and deposition of atmospheric nitrogen compounds. Of particular emphasis within ANICE is the influence of coastal zone processes. Both short episodes with high deposition and chronic nitrogen inputs are considered in the project. The improved transport–chemistry models will be used to assess the atmospheric inputs of nitrogen compounds into the European regional seas (the North Sea is studied as a prototype) and evaluate the impact of various emission reduction strategies on the atmospheric nitrogen loads. Assessment of the impact of atmospheric nitrogen on coastal ecosystems will be based on comparisons of phytoplankton nitrogen requirements, other external nitrogen inputs to the ANICE area of interest and the direct nitrogen fluxes provided by ANICE. Selected results from both the experimental and modelling components are presented here. The experimental results show the large spatial and temporal variability in the concentrations of gaseous nitrogen compounds, and their influences on fluxes. Model calculations show the strong variation of both concentrations and gradients of nitric acid at fetches of up to 25 km. Aerosol concentrations also show high temporal variability and experimental evidence for the reaction between nitric acid and sea salt aerosol is provided by size-segregated aerosol composition measured at both sides of the North Sea. In several occasions throughout the experimental period, air mass back trajectory analysis showed connected flow between the two sampling sites (the Weybourne Atmospheric Observatory on the North Norfolk coast of the UK and Meetpost Noordwijk, a research tower at 9 km off the Dutch coast). Results from the METRAS/SEMA mesoscale chemistry transport model system for one of these cases are presented. Measurements of aerosol and rain chemical composition, using equipment mounted on a commercial ferry, show variations in composition across the North Sea. These measurements have been compared to results obtained with the transport–chemistry model ACDEP which calculates the atmospheric inputs into the whole North Sea area. Finally, the results will be made available for the assessment of the impact of atmospheric nitrogen on coastal ecosystems.

Environmental scenarios for the future nitrogen policy in Flanders, Belgium.

The agricultural sector accounts for two thirds of nitrogen losses in Flanders, Belgium. Since 1991 both the government and the farmers have been taking measures to reduce the nitrogen surplus. Initially, the manure policy was aimed at distributing the manure surplus equally across Flanders. At the same time, the growth of livestock was stopped by a strict licensing policy, which required “command and control” measures. In recent years, the policy has switched to the use of individual target commitments by farmers. The Flemish manure policy will be tightened even more as a result of international pressures. An ex ante evaluation of possible policy options was carried out using three different scenarios spread out until 2010 (Business As Usual, Additional Measures, and Sustainable Development). To do this, a sector-economic, regionalized, environmental, comparative static, partial equilibrium, mathematical programming model of the Flemish agriculture was developed. The nitrogen emission into the agricultural soil was calculated by means of a regional soil balance. European targets can only be reached with manure processing, reduced fertilizer usage, and a strong reduction of intensive livestock breeding activities. The atmospheric deposition of nitrogen compounds will strongly decrease in 2010 if additional measures are taken. This will also result in a strong reduction of nitrous oxide emissions.

Deposition of atmospheric nitrogen compounds in humid tropical Cuba.

Acid deposition, a direct effect of gaseous air pollutants, is causing widespread damage to terrestrial and aquatic ecosystems. Further, these pollutants are responsible for the corrosion of building materials and cultural objects, as well as having an impact on human health. In Cuba, main atmospheric deposition of nitrogen compounds varies from approximately 12.0 to 65.0 kg N ha(-1) year(-1) in rural areas. Ammonia and ammonium are the most important elements in Cuba's tropical conditions.

Modelling the effect of atmospheric deposition on shallow heathland lakes in the Netherlands: dry deposition on water — now you see it, now you don't

The most important nitrogen source for isolated heathland lakes in the Netherlands is the atmospheric deposition of nitrogen compounds. Calculations were performed to relate in-lake concentrations with deposition. Using a dynamic retention model, all major components deposited (NH 4 +, NO 3 − and SO 4 2−) appeared to be retained by the lake. Simulations with the aquatic ecosystem model Aqu. Acid showed a big discrepancy between calculated and measured concentrations when using the estimated total deposition. However, using only wet deposition data, a reasonable fit with measured data was obtained. It was concluded that the dry deposition of nitrate and ammonium actually entering the lakes was far lower than the deposition estimated. The reasons for the apparent absence of dry deposition of nitrogen compounds on heathland lakes in general, and the impact on estimates of critical nitrogen deposition, are discussed.

Atmospheric deposition of nitrogen compounds in the Czech Republic

This study presents estimates of dry and wet deposition of nitrogen compounds in the Czech Republic. Deposition has been estimated from monitored and modelled concentrations in the atmosphere and in precipitation, where the most important nitrogen compounds are nitrogen oxides and ammonia, and their reaction products. Measured atmospheric concentrations of NO x, NH 3 and of aerosol particles (NO 3 − and NH 4 +), along with measured concentrations of NO 3 − and NH 4 + in precipitation, weighted by precipitation amounts, were interpolated with a properly used Kriging technique on a 10 × 10 km grid covering the whole Czech Republic. Wet deposition was derived from concentration values for NO 3 − and NH 4 + in precipitations and from precipitation amounts. Dry deposition was derived from concentrations of gaseous components and aerosol in the air, and from their deposition velocities. A resistance model was used for calculating NO x, NH 3 deposition velocities; deposition velocities of HNO 3 were derived from the literature and deposition velocities of particles were parameterized. The annual average NO y deposition in the Czech Republic in 1994 was estimated at 972 eq H + ha −1 a −1 and the annual average NH x deposition at 887 eq H + ha −1 a −1.

Nitrogen pollution in the European Union – origins and proposed solutions

SummaryThe European Union is faced with major environmental problems related to nitrogen (N) compounds. The origins of three such problems, the atmospheric deposition of N compounds, the leaching of nitrates to ground-water and the anthropogenic N-input to the North Sea, are investigated by means of a Substance Flow Analysis (SFA); the reference year is 1988. Although the problems occur at various scales and have varying direct causes, food production and consumption together are the main responsible sectors, and the production and import of fertilizer appear to be the major ultimate sources in all three cases. Measures to combat these problems have been agreed to in various international frameworks: the European Community, the International North Sea Conference and the Rhine States Conference. These measures include technical emission reduction for acidifying compounds resulting in a 30% emission reduction; extension of the sewage treatment network and application of denitrification with 50% effectiveness; and introduction of measures directed at efficiency increase and emission reduction in agricultural practice in 10% of the agricultural area. The recent changes in the Common Agricultural Policy (CAP) are not expected to lead to significant changes in N flows. Assuming full implementation, an almost sufficient 45% reduction is expected for the anthropogenic nitrogen input into the North Sea. The atmospheric deposition of nitrogen compounds will be reduced by approximately 20%. The leaching of nitrates to the ground-water is expected to remain at the current level or even to increase a little. In all, these measures are conducive to solving, but do not satisfactorily solve, the three problems, mainly because the ultimate origins of the problems are not sufficiently influenced and measures therefore inevitably result in a shifting of problems.

Atmospheric nitrogen input to the Kattegat

Abstract An overview is given of the processes involved in the atmospheric deposition of nitrogen compounds. These processes are incorporated in an atmospheric transport model that is used to calculate the nitrogen input to the Kattegat, the sea area between Denmark and Sweden. The model results show that the total atmospheric nitrogen input to the Kattegat is approximately 960 kg N km2 yr1. The nitrogen input to the Kattegat is dominated by the wet depositions of NHx (42%) and NOy (30%). The contribution from the dry deposition of NHx is 17% and that of the dry deposition of NOy is 11 %. The contribution of the atmospheric input of nitrogen to the Kattegat is about 30% of the total input including the net transport from other sea areas, runoff etc.

Vulnerability to diffuse pollution and average nitrate contamination of european soils and groundwater

From the Atlantic Ocean to the Ural Mountains, European soils are threatened by diffuse pollution from modern agriculture and increased atmospheric deposition. The vulnerability of the soil to diffuse pollution depends on land cover, topsoil features, net precipitation, aquifer type, groundwater recharge and age. The elaboration of the various elements was realized by applying Geographical Information Systems (GISs). Precipitation and the actual evapotranspiration were estimated using meteorological data. The resulting net precipitation is discharged by groundwater recharge and surfacial runoff, with the division of net precipitation in groundwater recharge and surfacial flow following from climate and soil features. The average groundwater age was based on aquifer depth, porosity and the recharge. The vulnerabilities of the soil and groundwater were estimated by establishing a ranking of the combined risks of a diffuse contamination for the topsoil and for groundwater in aquifers. Nitrogen compounds in soils are caused mainly by manuring and fertilization of agricultural lands and atmospheric deposition. The varying doses of fertilizer and manure and the atmospheric deposition of nitrogen compounds were assessed for an actual situation. Only part of the applied doses leached into the soil. The leaching of nitrate to a level of 1 m below land surface was estimated by applying empirical relations derived from the northwest European experience, based on land use, features of the topsoil and net precipitation. The subsequent leaching to deeper strata and a further denitrification also depend on groundwater recharge and aquifer type. The average nitrate concentration in the various aquifers was assessed by estimating the nitrogen doses to European soils in the course of time in combination with the groundwater age. Results, attained using GIS and presented in the form of maps, show the leaching of nitrate concentrations to a level of 1 m below land surface and also the average concentration in the upper aquifer system.

Vulnerability to diffuse pollution and average nitrate contamination of European soils and groundwater

From the Atlantic Ocean to the Ural Mountains, European soils are threatened by diffuse pollution from modem agriculture and increased atmospheric deposition. The vulnerability of the soil to diffuse pollution depends on land cover, topsoil features, net precipitation, aquifer type, groundwater recharge and age. The elaboration of the various elements was realized by applying Geographical Information Systems (GISs). Precipitation and the actual evapotranspiration were estimated using meteorological data. The resulting net precipitation is discharged by groundwater recharge and surfacial runoff, with the division of net precipitation in groundwater recharge and surfacial flow following from climate and soil features. The average groundwater age was based on aquifer depth, porosity and the recharge. The vulnerabilities of the soil and groundwater were estimated by establishing a ranking of the combined risks of a diffuse contamination for the topsoil and for groundwater in aquifers. Nitrogen compounds in soils are caused mainly by manuring and fertilization of agricultural lands and atmospheric deposition. The varying doses of fertilizer and manure and the atmospheric deposition of nitrogen compounds were assessed for an actual situation. Only part of the applied doses leached into the soil. The leaching of nitrate to a level of 1 m below land surface was estimated by applying empirical relations derived from the northwest European experience, based on land use, features of the topsoil and net precipitation. The subsequent leaching to deeper strata and a further denitrification also depend on groundwater recharge and aquifer type. The average nitrate concentration in the various aquifers was assessed by estimating the nitrogen doses to European soils in the course of time in combination with the groundwater age. Results, attained using GIS and presented in the form of maps, show the leaching of nitrate concentrations to a level of 1 m below land surface and also the average concentration in the upper aquifer system.

Does (K+Mg+Ca+P) fertilization lead to recovery of tree health in a nitrogen stressed Quercus rubra L. stand?

In The Netherlands atmospheric deposition of nitrogen compounds to forest ecosystems has been very high for some decades and has led to severe nutritional imbalances in soils as well as in trees. At this moment legislation is not fully in effect with respect to lowering emission/deposition fluxes, particularly of nitrogen. The trees suffer mainly from severe magnesium, potassium and calcium and sometimes phosphorus deficiencies. In this study it was investigated whether fertilization with potassium, magnesium, calcium and phosphorus could prevent a Quercus rubra stand from further decline by restoring the nutritional balance, though the detrimental input of nitrogen compounds still continues. Three fertilization treatments were applied: (i) a standard dose of 1250 kg.ha −1 containing 60 kg P.ha −1 (as P 2O 5), 100 kg K.ha −1 (as K 2O), 80 kg Mg.ha −1 (as MgO) and 340 kg Ca.ha −1 (as CaCO 3); (ii) two times the standard dose; and (iii) three times the standard dose. Soil solution chemistry showed that the highest dose led to the most significant results: an improved nutrient balance and an increased availability of nutrients. After one growing season following fertilization, the trees looked much healthier and crown density had increased. This revitalization lasted for at least four years. For tree health the mid dose seemed appropriate. After the first growing season potassium is the most mobile nutrient, in the soil and also in the trees, but tended to decrease in the fourth year after fertilization. Magnesium and calcium reached normal values in the leaves after four growing seasons. No obvious effects of phosphorus were found.

Enhancement of nitrogen deposition to forest trees exposed to SO2

DEPOSITION of atmospheric nitrogen compounds, particularly ammonia, is postulated to have a variety of deleterious effects1, including damage to soils, trees and other vegetation1-6. We report here that fumigation of coniferous trees in the open air with sulphur dioxide (13 and 22 p.p.b.–parts in 109 by volume) produced an increased deposition of atmospheric NH3 to foliage. A mechanism for co-deposition of NH3 and SO2 to wet surfaces has been suggested7,8. As concentrations of NH3 at the site are not unusually high (annual mean, 4p.p.b.)9, this mechanism may enhance nitrogen deposition over large areas of Europe. It may also account for some results of experimental fumigations previously attributed to SO2 alone.