The effect of climate on the mineralogical properties of soils from the Val Genova valley Trentino (Italy)

Five soils developing along an altitudinal transect in the Val Geneva valle y were studied with the purpose of evaluating the influence of the climate on their chemical and mineralogical characteristics. Soils developed from a granitic parent material and those at the middle altitude exhibited Spodic features. Mineralogical investigation has pointed out that in the surface horizon all the soils but one showed the presence of a low charge expandabl e clay mineral, formed through the removal of the hydroxy interlayers from chlorite or chlorite/vermiculite intergrades and the reduction of layer cha rge. The exception was the soil developed at the lowest elevation. It seems that the variation of climate, even in a narrow space range, may influence soil weathering. Soils at the intermediate altitudes appeared to be more s ensitive to an increase in the acidity, because of the resultant increase i n the removal of Al from the interlayers of clay minerals.