title: Critical loads and their exceedances at intensive forest monitoring sites in Europe.
abstract: Intensive forest monitoring by means of harmonised methods has been conducted in Europe for more than a decade. Risks of atmospheric nitrogen and sulphur deposition are assessed by means of calculations of critical loads and their exceedances. In the present study throughfall and bulk deposition of nitrate (N-NO(3)), ammonium (N-NH(4)) and sulphate (S-SO(4)) show marked spatial patterns and temporal trends. In the period of observation (1999-2004), sulphate deposition on intensive monitoring plots decreased by about one quarter. This is in line with the reduction of S deposition by 70% since 1981 in Europe as a result of successful air pollution control politics under the Convention on Long-range Transboundary Air Pollution (CLRTAP). However, sulphate and especially nitrate and ammonium deposition were found to still exceed critical loads at many forest sites, indicating a continued need for further implementation of air pollution abatement strategies.
authors.affiliation: Federal Research Centre for Forestry and Forest Products, Leuschnerstr. 91, D-21031 Hamburg, Germany. martin.lorenz@vti.bund.de
authors.forename: Martin
authors.initials: M
authors.lastname: Lorenz
authors.forename: Hans-Dieter
authors.initials: HD
authors.lastname: Nagel
authors.forename: Oliver
authors.initials: O
authors.lastname: Granke
authors.forename: Philipp
authors.initials: P
authors.lastname: Kraft
mesh_terms: D015258:Acid Rain; D000393:Air Pollutants / Q000032:analysis / Q000633:toxicity*; D004784:Environmental Monitoring / Q000379:methods*; D005060:Europe; D009584:Nitrogen / Q000032:analysis / Q000633:toxicity; D000644:Quaternary Ammonium Compounds / Q000032:analysis / Q000633:toxicity; D012306:Risk; D012621:Seasons; D013431:Sulfates / Q000032:analysis / Q000633:toxicity; D013995:Time; D014197:Trees / Q000187:drug effects / Q000254:growth & development*
chemical_list: D015258:Acid Rain; D000393:Air Pollutants; D000644:Quaternary Ammonium Compounds; D013431:Sulfates; D009584:Nitrogen