Chemical soil conditions in pristine Nothofagus forests of New Zealand as compared to German forests.
In many German forest soils low base saturation in deeper soil layers was reported and acidic deposition is seen as the major cause for this. This hypothesis was tested by sampling 5 New Zealand forest soils from pristine beech (Nothofagus fusca, N. menziesii, N. solandri) sites under climatic and geological conditions comparable to higher elevations in Germany. The soils developed from granite and greywacke. Soil samples were analysed for pH and the exchangeable cations were extracted with 1smallcap˜M NH4Cl. The base saturation of all soil profiles was very low, even in deeper layers and was thus similar to the patterns found in many German forest soils. The pH was generally higher in the New Zealand soils compared with Germany. The reason for the depletion of base cations in deeper soil layers of New Zealand forest soils was thought to be the leaching of base cations with HCO3- resulting from the dissociation of carbonic acid in connection with high amounts of seepage. It is concluded that under high rainfall conditions, the low base saturation found in deeper layers of forest soils cannot exclusively be attributed to the effects of acidic depositions and land use.