An assessment of the recent trend of pH and base cation content in some forest soils in the Vosges Mountains (north-east France).

In two series of sites in the Vosges massif, soils were sampled after a 20 year interval. The comparison of the base cation content of the organomineral horizon Al showed high exchangeable calcium and magnesium losses, which are only statistically significant in the 'cartographie' series. In these soils the mean saturation level of the Al horizons decreased from 10.8 to 7.3 (32%); however, pH was not affected. In podzolic soils in the 'Hospices de Nancy' series, an increase in organic carbon content, and a subsequent increase in the CEC, produce uncertainties with respect to data interpretation. In brown soils, however, a true decrease in the saturation rate seems to have occurred during this short period.