Die kurzfristige pH-Pufferung von gestörten und ungestörten Waldbodenproben

Short-timed pH-buffering of disturbed and undisturbed forest soil samples The pH buffering of disturbed and undisturbed soils under spruce (podzol and podzolic cambisol derived from phyllite, eutric cambisol derived from basalt) was studied in the laboratory by adding H₂SO₄ in ecologically relevant concentrations (pH 5.6–2.0). For the cambisol with crumb structure no difference was found. 80–90% of the added protons were neutralized by release of Ca and Mg. Disturbed samples of the podzol buffer less than 70% of the applicated acid. For undisturbed samples the maximum buffering rate of 185 g H⁺/ha · h is reached with a proton load of about 500 g H⁺/ha · h (related to 4 cm soil depth). Buffering behaviour of the podzolic cambisol lies between the podzol and the cambisol. 70–90% of the proton input is buffered in the disturbed samples while the undisturbed one does not reach its maximum buffering rate, even with high proton load. In this soil Al-release is the most reactive buffer.