Reassessment of Critical Levels for Atmospheric Ammonia

Cape, J. N.; Eerden, L.J. van der; Sheppard, Lucy J.; Leith, Ian D.; Sutton, Mark A.

doi:10.1007/978-1-4020-9121-6_2

Cited by 17 publications

(15 citation statements)

References 22 publications

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“…We rarely had data to distinguish biotic or ecosystem response to reduced forms vs. oxidized forms of N. There is some evidence that, for some species, reduced forms of N may have more substantial impacts than oxidized forms (Bobbink et al 2003, Kleijn et al 2008, Cape et al 2009). Differences in uptake rates and preference for NH 4 þ vs. NO 3 À across different plant taxa (Falkengren-Grerup 1995, McKane et al 2002, Miller and Bowman 2002, Nordin et al 2006) lead to differences in sensitivity to NH x (Krupa 2003) and NO y .…”

Section: Depositionmentioning

confidence: 99%

Effects of nitrogen deposition and empirical nitrogen critical loads for ecoregions of the United States

Pardo

Fenn

Goodale

et al. 2011

Ecological Applications

402

342

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Abstract. Human activity in the last century has led to a significant increase in nitrogen (N) emissions and atmospheric deposition. This N deposition has reached a level that has caused or is likely to cause alterations to the structure and function of many ecosystems across the United States. One approach for quantifying the deposition of pollution that would be harmful to ecosystems is the determination of critical loads. A critical load is defined as the input of a pollutant below which no detrimental ecological effects occur over the long-term according to present knowledge.The objectives of this project were to synthesize current research relating atmospheric N deposition to effects on terrestrial and freshwater ecosystems in the United States, and to estimate associated empirical N critical loads. The receptors considered included freshwater diatoms, mycorrhizal fungi, lichens, bryophytes, herbaceous plants, shrubs, and trees. Ecosystem impacts included: (1) biogeochemical responses and (2) individual species, population, and community responses. Biogeochemical responses included increased N mineralization and nitrification (and N availability for plant and microbial uptake), increased gaseous N losses (ammonia volatilization, nitric and nitrous oxide from nitrification and denitrification), and increased N leaching. Individual species, population, and community responses included increased tissue N, physiological and nutrient imbalances, increased growth, altered root : shoot ratios, increased susceptibility to secondary stresses, altered fire regime, shifts in competitive interactions and community composition, changes in species richness and other measures of biodiversity, and increases in invasive species.The range of critical loads for nutrient N reported for U.S. ecoregions, inland surface waters, and freshwater wetlands is 1-39 kg NÁha , spanning the range of N deposition observed over most of the country. The empirical critical loads for N tend to increase in the following sequence for different life forms: diatoms, lichens and bryophytes, mycorrhizal fungi, herbaceous plants and shrubs, and trees.The critical load approach is an ecosystem assessment tool with great potential to simplify complex scientific information and communicate effectively with the policy community and the public. This synthesis represents the first comprehensive assessment of empirical critical loads of N for major ecoregions across the United States.

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Section: Depositionmentioning

confidence: 99%

Effects of nitrogen deposition and empirical nitrogen critical loads for ecoregions of the United States

Pardo

Fenn

Goodale

et al. 2011

Ecological Applications

402

342

View full text Add to dashboard Cite

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“…Studies suggest the emission of NH 3 gas is likely to negatively impact local 51 ecosystems causing acidification and eutrophication, which has been shown to alter 52 local interspecies competition and biodiversity (Cape et al, 2009;Sutton et al, 2011Sutton et al, , 53 2012. Currently, the biogeochemical processes following the addition of seabird 54 derived N r to the surface of land are not well understood.…”

Section: A C C E P T E D Accepted Manuscriptmentioning

confidence: 99%

Measurement of ammonia emissions from temperate and sub-polar seabird colonies

Riddick

Blackall

Dragosits

et al. 2016

Atmospheric Environment

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“…In tandem, revised UNECE "Critical Levels" (CLe) of NH 3 concentrations to protect sensitive vegetation and ecosystems were adopted in 2007 (UN- ECE, 2007). These set limits of NH 3 concentrations to 1 and 3 µg NH 3 m −3 annual mean for the protection of lichensbryophytes and other vegetation, respectively (Cape et al, 2009b). The new CLes replaced the previous single value of 8 µg NH 3 m −3 (annual mean) and have since been adopted as part of the revised Gothenburg Protocol.…”

Section: Introductionmentioning

confidence: 99%

Drivers for spatial, temporal and long-term trends in atmospheric ammonia and ammonium in the UK

et al. 2018

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Abstract. A unique long-term dataset from the UK National Ammonia Monitoring Network (NAMN) is used here to assess spatial, seasonal and long-term variability in atmospheric ammonia (NH 3 : 1998(NH 3 : -2014) and particulate ammonium (NH + 4 : 1999-2014) across the UK. Extensive spatial heterogeneity in NH 3 concentrations is observed, with lowest annual mean concentrations at remote sites (< 0.2 µg m −3 ) and highest in the areas with intensive agriculture (up to 22 µg m −3 ), while NH + 4 concentrations show less spatial variability (e.g. range of 0.14 to 1.8 µg m −3 annual mean in 2005). Temporally, NH 3 concentrations are influenced by environmental conditions and local emission sources. In particular, peak NH 3 concentrations are observed in summer at background sites (defined by 5 km grid average NH 3 emissions < 1 kg N ha −1 yr −1 ) and in areas dominated by sheep farming, driven by increased volatilization of NH 3 in warmer summer temperatures. In areas where cattle, pig and poultry farming is dominant, the largest NH 3 concentrations are in spring and autumn, matching periods of manure application to fields. By contrast, peak concentrations of NH + 4 aerosol occur in spring, associated with long-range transboundary sources. An estimated decrease in NH 3 emissions by 16 % between 1998 and 2014 was reported by the UK National Atmospheric Emissions Inventory. Annually averaged NH 3 data from NAMN sites operational over the same period (n = 59) show an indicative downward trend, although the reduction in NH 3 concentrations is smaller and nonsignificant: Mann-Kendall (MK), −6.3 %; linear regression (LR), −3.1 %. In areas dominated by pig and poultry farming, a significant reduction in NH 3 concentrations between 1998 and 2014 (MK: −22 %; LR: −21 %, annually averaged NH 3 ) is consistent with, but not as large as the decrease in estimated NH 3 emissions from this sector over the same period (−39 %). By contrast, in cattle-dominated areas there is a slight upward trend (non-significant) in NH 3 concentrations (MK: +12 %; LR: +3.6 %, annually averaged NH 3 ), despite the estimated decline in NH 3 emissions from this sector since 1998 (−11 %). At background and sheep-dominated sites, NH 3 concentrations increased over the monitoring period. These increases (non-significant) at background (MK: +17 %; LR: +13 %, annually averaged data) and sheep-dominated sites (MK: +15 %; LR: +19 %, annually averaged data) would be consistent with the concomitant reduction in SO 2 emissions over the same period, leading to a longer atmospheric lifetime of NH 3 , thereby increasing NH 3 concentrations in remote areas. The observations for NH 3 concentrations not decreasing as fast as estimated emission trends are consistent with a larger downward trend in annual particulate NH + 4 concentrations (1999-2014: MK: −47 %; LR: −49 %, p < 0.01, n = 23), associated with a lower formation of particulate NH

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Reassessment of Critical Levels for Atmospheric Ammonia

Cited by 17 publications

References 22 publications

Effects of nitrogen deposition and empirical nitrogen critical loads for ecoregions of the United States

Effects of nitrogen deposition and empirical nitrogen critical loads for ecoregions of the United States

Measurement of ammonia emissions from temperate and sub-polar seabird colonies

Drivers for spatial, temporal and long-term trends in atmospheric ammonia and ammonium in the UK

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