Atmospheric Ammonia

Ammonia Critical Thresholds.- Reassessment of Critical Levels for Atmospheric Ammonia.- Potential for the Further Development and Application of Critical Levels to Assess the Environmental Impacts of Ammonia.- Long-Term Cumulative Exposure Exacerbates the Effects of Atmospheric Ammonia on an Ombrotrophic Bog: Implications for Critical Levels.- The Application of Transects to Assess the Effects of Ammonia on Woodland Groundflora.- Estimation of the Ammonia Critical Level for Epiphytic Lichens Based on Observations at Farm, Landscape and National Scales.- Mapping Ammonia Emissions and Concentrations for Switzerland - Effects on Lichen Vegetation.- Over Which Averaging Period is the Ammonia Critical Level Most Precautionary?.- Macrolichens on Twigs and Trunks as Indicators of Ammonia Concentrations Across the UK - a Practical Method.- Assessment of Critical Levels of Atmospheric Ammonia for Lichen Diversity in Cork-Oak Woodland, Portugal.- Temporal Trends in Atmospheric Ammonia.- Linking Ammonia Emission Trends to Measured Concentrations and Deposition of Reduced Nitrogen at Different Scales.- Long-Term Record (1981-2005) of Ammonia and Ammonium Concentrations at K-Puszta Hungary and the Effect of Sulphur Dioxide Emission Change on Measured and Modelled Concentrations.- Assessment of Ammonia and Ammonium Trends and Relationship to Critical Levels in the UK National Ammonia Monitoring Network (NAMN).- Review of Published Studies Estimating the Abatement Efficacy of Reduced-Emission Slurry Spreading Techniques.- Analysis of Ammonia Hotspots.- Ammonia Deposition Near Hot Spots: Processes, Models and Monitoring Methods.- Standardised Grasses as Biomonitors of Ammonia Pollution Around Agricultural Point Sources.- Soluble Ammonium in Plants as a Bioindicator forAtmospheric Nitrogen Deposition: Refinement and Testing of a Practical Method.- Spatial Planning as a Complementary Tool to Abate the Effects of Atmospheric Ammonia Deposition at the Landscape Scale.- Regional Modelling of Atmospheric Ammonia.- Modelling of the Atmospheric Transport and Deposition of Ammonia at a National and Regional Scale.- Application of a Lagrangian Model FRAME to Estimate Reduced Nitrogen Deposition and Ammonia Concentrations in Poland.- Application of the EMEP Unified Model to the UK with a Horizontal Resolution of 5 × 5 km2.- Conclusions and Outlook.- Critical Levels for Ammonia.- Detecting Change in Atmospheric Ammonia Following Emission Changes.- Assessment Methods for Ammonia Hot-Spots.- Modelling the National and Regional Transport and Deposition of Ammonia.- Reliability of Ammonia Emission Estimates and Abatement Efficiencies.- Ammonia Policy Context and Future Challenges.- Synthesis and Summary for Policy Makers.