Water, Air and Soil Pollution: Focus

, Volume 1, Issue 1–2, pp 91–101 | Cite as

Critical Loads of Acidity for Forest Soils: Tentative Modifications

  • Maria Holmberg
  • Jan Mulder
  • Maximilian Posch
  • Michael Starr
  • Martin Forsius
  • Matti Johansson
  • Jesper Bak
  • Hannu Ilvesniemi
  • Harald Sverdrup


We reviewed the current methods for calculatingcritical loads of acidity for forest soils. The consequencesof four sets of assumptions concerning the soil modelstructure, parameter values and the critical loads criterionwere explored by comparing the values of the averageaccumulated exceedance (AAE) calculated for Finland withdeposition values for the year 1995. The AAE index is given inthe unit of deposition and is a measure of how far a region isfrom being protected in terms of fulfilling a certaincriterion, taking into account the size of the ecosystem areas.Using a critical limit for the molar ratio of theconcentrations of base cations to aluminium in soil solutiongave the lowest average accumulated exceedance. Assumingorgano-aluminium complexes and leaching of organic anions gaveAAE = 4 eq ha-1 a-1, which was close to the valueobtained with the standard approach used in Finland, assuminggibbsite equilibrium and no leaching of organic anions,yielding AAE = 5 eq ha-1 a-1. With a critical basesaturation limit, instead of the concentrations criterion, theAAE index was 17 eq ha-1 a-1. The highest averageaccumulated exceedance (AAE = 25 eq ha-1 a-1),corresponding to the lowest critical load, was obtained whenthe effects-based criterion (critical concentration or criticalbase saturation) was substituted with one restricting thedeterioration of the neutralizing capacity of the soil, ANCle(crit) = 0. These tests illustrate the variabilityof the critical load values for acidity that can be introducedby changing the criterion or by varying the calculation method,without, however, representing the extreme values of criticalloads that could be derived.

acid neutralizing capacity base saturation critical loads forest soils organic complexes 


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  1. Berge, E. (ed.): 1997, Transboundary Air Pollution in Europe. Part 1: Emissions, Dispersion and Trends of Acidifycing and Eutrophying Agents, Meteorological Synthesizing Centre West, The Norwegian Meteorological Institute, Oslo, Norway, EMEP/MSC-W Report 1/97, 108 pp.Google Scholar
  2. Berggren, D. and Mulder, J.: 1995, 'The role of organic matter in controlling aluminium solubility in acidic soil horizons', Geochim. Cosmochim. Acta 59, 4167-4180.Google Scholar
  3. Bergström, I., Mäkelä, K. and Starr, M. (eds): 1995, Integrated Monitoring Programme in Finland. First National Report. Ministry of the Environment, Environmental Policy Department, Helsinki, Report 1, 138 pp.Google Scholar
  4. Cronan, C. S. and Grigal, D. F.: 1995, 'Use of calcium/aluminum ratios as indicators of stress in forest ecosystems', J. Environ. Qual. 24, 209-226.Google Scholar
  5. De Vries, W.: 1991, Methodologies for the Assessment and Mapping of Critical Loads and of the Impact of Abatement Strategies on Forest Soils, The Winand Staring Centre for Integrated Land, Soil and Water Research, Report 46, Wageningen, The Netherlands, 109 pp.Google Scholar
  6. Driscoll, C. T., Lehtinen, M. D. and Sullivan, T. J.: 1994, 'Modeling the acid-base chemistry of organic solutes in Adirondack, New York, lakes', Wat. Resour. Res. 30, 297-306.Google Scholar
  7. Gaines, G. L. and Thomas, H. C.: 1953, 'Adsorption studies on clay minerals. II. A formulation of the thermodynamics of exchange adsorption', J. Chem. Phys. 21(4), 714-718.Google Scholar
  8. Forsius, M., Kämäri, J. and Posch, M.: 1992, 'Critical loads for Finnish lakes: Comparison of three steady-state models', Env. Poll. 77, 185-193.Google Scholar
  9. Johansson, M.: 1999, 'Integrated models for the assessment of air pollution control requirements', Monographs of the Boreal Environment Research 13, Helsinki, 73 pp.Google Scholar
  10. Johansson, M., Ahonen, J., Amann, M., Bartnicki, J., Ekqvist, M., Forsius, M., Karvosenoja, N., Lindström, M., Posch, M., Suutari, R. and Syri, S.: 2000, Integrated Environmental Assessment Modelling. Final Report of the Finnish Subproject EU/Life Project. Finnish Environment Institute 387, Helsinki, 105 pp.Google Scholar
  11. Jongmans, A. G. et al.: 1997, 'Rock-eating fungi', Nature 389, 682-683.Google Scholar
  12. Kleemola, S. and Forsius, M.: 1998, 'ICP IM Activities, Monitoring Sites and Available Data' in S. Kleemola and M. Forsius (eds.), 7th Annual Report 1998. UN ECE ICP Integrated Monitoring', The Finnish Environment 217, pp. 6-14.Google Scholar
  13. Løkke, H., Bak, J., Falkengren-Grerup, U., Finlay, R. D., Ilvesniemi, H., Nygaard, P.-H. and Starr, M.: 1996, 'Critical loads of acidic deposition for forest soils: Is the current approach adequate?', Ambio 25, 510-516.Google Scholar
  14. Meiwes, K. J., Khanna, P. K. and Ulrich, B.: 1986, 'Parameters for describing soil acidification and their relevance to the stability of forest ecosystems', For. Ecol. Manage. 15, 161-179.Google Scholar
  15. Mulder, J.: 2000, 'Including the role of soil organic matter on Al3+-concentrations in critical load calculations' in Critical Loads Calculations: Developments and Tentative Applications, Tema Nord 566, 6-7, Copenhagen Nordic Council of Ministers.Google Scholar
  16. Mulder J. and Stein A.: 1994, 'The solubility of aluminum in acidic forest soils: Long-term changes due to acid deposition', Geochim. Cosmochim. Acta 58, 85-94.Google Scholar
  17. Müller-Edzards, C., De Vries, W. and Erisman, J. (eds.): 1997, Ten Years of Monitoring Forest Condition in Europe. Studies on Temporal Development, Spatial Distribution and Impacts of Natural and Anthropogenic Stress Factors, EC-UN/ECE, Brussels, Geneva, 386 pp.Google Scholar
  18. Nissinen, A., Kareinen T., Tanskanen N. and Ilvesniemi H.: 1999, 'Apparent cation-exchange equilibria and aluminium solubility in solutions obtained from two acidic forest soils by centrifuge drainage method and suction lysimeters', Water, Air, and Soil Pollut. 119, 23-43.Google Scholar
  19. Oliver, B. G., Thurman E. M. and Malcolm R. I.: 1983, 'The contribution of humic substances to the acidity of colored natural waters', Geochim. Cosmochim. Acta 47, 2031-2035.Google Scholar
  20. Posch, M.: 2000, 'Critical Loads of Acidity: PossibleModifications', in Critical Loads Calculations: Developments and Tentative Applications, Tema Nord 2000: 566, 8-23, Copenhagen, Nordic Council of Ministers.Google Scholar
  21. Posch, M., de Smet, P. A. M., Hettelingh, J.-P. and Downing, R. J. (eds.): 1999, Calculation and Mapping of Critical Thresholds in Europe: CCE Status Report 1999. National Institute of Public Health and the Environment (RIVM) Rep. 259101009, Bilthoven, The Netherlands, 165 pp.Google Scholar
  22. Reuss, J. O.: 1977, 'Chemical and biological relationships relevant to the effect of acid rainfall on the soil-plant system', Water, Air, and Soil Pollut. 7, 461-478.Google Scholar
  23. Reuss, J.O.: 1983, 'Implications of the calcium-aluminium exchange system for the effect of acid precipitation in soils', J. Environ. Qual. 12, 591-595.Google Scholar
  24. Reuss, J. O. and Johnson D. W.: 1986, Acid Deposition and the Acidification of Soils and Waters, Ecological Studies 59, Springer, New York, 120 pp.Google Scholar
  25. Starr, M.: 2000, 'Soil Chemical Criteria and Biological Indicator Effects', in Critical Loads Calculations: Developments and Tentative Applications, Tema Nord 2000: 566, 2-5, Copenhagen, Nordic Council of Ministers.Google Scholar
  26. Starr, M. and Ukonmaanaho, L.: 1995, 'Soil Water', in I. Bergström, K. Mäkelä and M. Starr (eds.), Integrated Monitoring Programme in Finland. First National Report, Ministry of the Environment, Environmental Policy Department, Helsinki, Report 1, pp. 74-75.Google Scholar
  27. Sverdrup, H. and de Vries, W.: 1994, 'Calculating critical loads for acidity with the simple mass balance method', Water, Air, and Soil Pollut. 72, 143-162.Google Scholar
  28. Sverdrup, H. and Warfvinge, P.: 1993, 'The effect on soil acidification on the growth of trees, grass and herbs as expressed by the (Ca+Mg+K)/Al ratio', Reports in Ecology and Environmental Engineering 2, Lund University, 104 pp.Google Scholar
  29. Tipping, E., Berggren, D., Mulder, J. and Woof, C.: 1995, 'Modelling the solid-solution distribution of protons, aluminium, base cations and humic substances in acid soils', Eur. J. Soil Sci. 46, 77-94.Google Scholar
  30. Ulrich, B.: 1966, 'Kationenaustauschgleichgewichte in Böden', Z. Pflanzenernähr. Bodenkd. 113, 141-159.Google Scholar
  31. UBA: 1996, Manual on Methodologies and Criteria for Mapping Critical Levels/Loads and Geographical Areas Where They Are Exceeded, Texte 71/96. Umweltbundesamt, Berlin, Germany, 144 + LXXIV pp.Google Scholar
  32. UN/ECE: 1999, Draft Protocol to the Convention on Long-Range Transboundary Air Pollution to abate acidification, eutrophication and ground-level ozone, Document EB.AIR/1999/1, UN/ECE, Geneva.Google Scholar
  33. UN/ECE and EC: 1999, Forest Condition in Europe, 1999 Executive Report, UN/ECE, EC, Geneva, Brussels, 31 pp.Google Scholar
  34. Vanmechelen, L., Groenemans, R., and Van Ranst, E. (eds): 1997, Forest Soil Condition in Europe. Results of a Large-Scale Soil Survey, EC, UN/ECE, and the Flemish Community, Brussels, Geneva, 259 pp.Google Scholar
  35. Walker, W. J., Cronan, C. S. and Bloom, P. R.: 1990, 'Aluminum solubility in organic horizons from northern and southern forested watersheds', Soil Sci. Soc. Am. J. 54, 369-374.Google Scholar

Copyright information

© Kluwer Academic Publishers 2001

Authors and Affiliations

  • Maria Holmberg
    • 1
  • Jan Mulder
    • 2
  • Maximilian Posch
    • 3
  • Michael Starr
    • 4
  • Martin Forsius
    • 5
  • Matti Johansson
    • 5
  • Jesper Bak
    • 6
  • Hannu Ilvesniemi
    • 7
  • Harald Sverdrup
    • 8
  1. 1.Finnish Environment InstituteHelsinkiFinland
  2. 2.Agr. UnivNorway
  3. 3.RIVM/CCEThe Netherlands
  4. 4.Finnish Forest Research InstituteFinland
  5. 5.Finnish Environment InstituteHelsinkiFinland
  6. 6.National Environmental Research InstituteDenmark
  7. 7.University of HelsinkiFinland
  8. 8.Lund UniversitySweden

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