Biogeochemistry

, Volume 8, Issue 1, pp 39–54 | Cite as

An empirical analysis of the factors contributing to 20-year decrease in soil pH in an old-field plantation of loblolly pine

  • Dan Binkley
  • David Valentine
  • Carol Wells
  • Ute Valentine
Article

Abstract

The pH of weak-acid solutions is controlled by acid concentration (HA + A), the degree of acid dissociation (A/HA), and the strength of the acids present (pKa). We developed an empirical approach that allows the relative importance of each of these factors to be estimated for soils. This empirical model was applied to soils collected from an old-field plantation of loblolly pine (Pinus taeda L.) at 5 and 25 years of age. During this period, soil pH dropped by 0.3 to 0.8 units, and extractable calcium, magnesium and potassium declined by 20 to 80%. The empirical model indicates that the decline in pH resulted largely from the reduction in base saturation of the exchange complex. However, the average acid strength of the exchange complex decreased during the 20 years, preventing a greater decline of perhaps 0.1 to 0.2 units in the observed pH. The rate of decrease in the acid neutralizing capacity to pH 3.5 was about 1.3 kmolc/ha annually, while the increase in base neutralizing capacity was about 2.7 and 1.6 kmolc/ha annually to pH 5.5 and 8.2, respectively. Extractable alkali and alkaline earth cations declined by about 2.2 kmolc/ha annually, matched by the rate of increase in aluminium. These changes demonstrated the dynamic nature of poorly buffered soils, and indicated that changes in soil acidity may be expected over a period of decades (especially following changes in land-use).

Key words

acid deposition forest decline soil acidification 

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References

  1. Anderson M (1987) The effects of forest plantations in some lowland soils. I. A second sampling of nutrient stocks. Forestry 60: 69–85Google Scholar
  2. Balmer WE, Owens EG & Jorgenson JR (1975) Effects of various spacings on loblolly pine growth 15 years after planting. USDA Forest Service Research Note SE-211, Asheville, NC. 7 pGoogle Scholar
  3. Binkley D (1986) Soil acidity in loblolly pine stands with interval burning. Soil Science Society of America Journal 50: 1590–1594Google Scholar
  4. Binkley D & Richter D (1987) Nutrient cycles and H+ budgets of forest ecosystems. Advances in Ecological Research 16: 1–51Google Scholar
  5. Binkley D, Driscoll CT, Allen HL, Schoeneberger P & D (1989) Acidic Deposition and Forest Soils: Context and case studies of the Southeastern U S. Ecological studies,volume 72. Springer-Verlag, New York. 150 pGoogle Scholar
  6. Bloom PR & Grigal DF (1985) Modeling soil response to acidic deposition in nonsulfate adsorbing soils. Journal of Environmental Quality 14: 489–495Google Scholar
  7. Bohn H, McNeal B & O'Connor G (1985) Soil Chemistry. Wiley, New York. 341 pGoogle Scholar
  8. Brand D, Kehoe P & Connors M (1986) Coniferous afforestation leads to soil acidification in central Ontario. Canadian Journal of Forest Research 16: 1389–1391Google Scholar
  9. Falkengren-Grerup U (1987) Long-term changes in pH of forest soils in Southern Sweden. Environmental Pollution 43: 79–90Google Scholar
  10. Hesse PR (1971) A Textbook of Soil Chemical Analysis. Chemical Publishing, New YorkGoogle Scholar
  11. McLean EO (1982) Soil pH and lime requirement. In: Page A, Miller R & Keeney D (Eds) Methods of Soil Analysis. Part 2, Chemical and Microbiological Properties (pp 199–224) American Society of Agronomy, MadisonGoogle Scholar
  12. Nilsson SI (1986) Critical deposition limits for forest soils. In: Nilsson J (Ed) Critical Loads for Nitrogen and Sulfur: Report from a Nordic Working Group (pp 37–69) Nordisk Ministerrad Miljo Rapport 1986: 11Google Scholar
  13. Perdue EM (1985) Acidic functional groups of humic substances. In: Aiken GR, McKnight DM, Wershaw RL & MacCarthy P (Eds) Humic Substances in Soil, Sediment and Water (pp 493–526) Wiley, New YorkGoogle Scholar
  14. Reuss JO & Johnson DW (1986) Acid deposition and acidification of soils and waters. Springer-Verlag, New York. 119 pGoogle Scholar
  15. Reuss JO, Christophersen N & Seip HM (1986) A critique of models for freshwater and soil acidification. Water, Air, and Soil Pollution 30: 909–930Google Scholar
  16. Schnoor JL Modeling of total acid precipitation impacts. Butterworth, New YorkGoogle Scholar
  17. Tabatabai MA (1985) Effect of acid rain on soils. CRC Critical Reviews in Environmental Control 15: 65–110Google Scholar
  18. Tamm CO & Hallbacken L (1986) Changes in soil pH over a 50-yr period under different forest canopies in SW Sweden. Water, Air, and Soil Pollution 31: 337–341Google Scholar
  19. Thomas GW (1982) Exchangeable cations. In: Page A, Miller R & Keeney D (Eds) Methods of Soil Analysis. Part 2, Chemical and Microbiological Properties (pp 159–166) American Society of Agronomy, MadisonGoogle Scholar
  20. Thomas GW & Hargrove WL (1984) The chemistry of soil acidity. In: Adams F (Ed) Soil Acidity and Liming (pp 3–56) American Society of Agronomy, MadisonGoogle Scholar
  21. Turner RS, Olson RJ & Brandt CC (1986) Areas having soils characteristics that may indicate sensitivity to acidic deposition under alternative forest damage hypotheses. Environmental Sciences Division Publication # 2720, Oak Ridge National Laboratory, TennesseeGoogle Scholar
  22. Turvey ND & Allen HL (1987) Site and cultural treatment effects and their interactions on four-year growth of loblolly pine. NCSFNC Report # 19, School of Forest Resources, North Caroline State University, Raleigh. 31 ppGoogle Scholar
  23. Ulrich B & Pankrath J (1983) Effects of accumulation of air pollutants in forest ecosystems. D. Reidel, BostonGoogle Scholar
  24. Van Breeman N, Mulder J & Driscoll CT (1983) Acidification and alkalinization of soils. Plant and Soil 75: 283–208Google Scholar

Copyright information

© Kluwer Academic Publishers 1989

Authors and Affiliations

  • Dan Binkley
    • 1
  • David Valentine
    • 1
  • Carol Wells
    • 2
  • Ute Valentine
    • 1
  1. 1.Dept. of Forest and Wood SciencesColorado State UniversityFt. Collins
  2. 2.USDA Forest ServiceSoutheastern Forest Experiment StationResearch Triangle Park

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