INFLUENCE OF PARENT MATERIAL AND CLIMATE ON ANDIC PROPERTIES OF SOILSIN A TEMPERATE MONTANE REGION (VOSGES, FRANCE)

The diverse environmental conditions (parent material, climate, vegeta tion) in the Vosges Mountains (France) allow us to investigate their r ole in the development of soils with varying degrees of andic properti es. We studied 13 profiles selected on the basis of lithological, ecol ogical and morphological criteria assumed to favour the formation of a ndic properties, i.e. basic parent materials of volcanic and other ori gins, wet montane climates and accumulation of thick layers of organic matter. The profiles belong to two classes: four are Andisols, more p recisely Alic Fulvudands, and the others are Andic Haplumbrepts with o nly weakly expressed andic properties. In this montane environment the factors favouring the andic properties seem to be on the one hand hei ght and exposure inducing cold and humid microclimates, and on the oth er the chemical and mineralogical composition controlling the weathera bility of the soil's parent materials. For example, the old volcanic r ocks on which most of the soils occur are poor in glassy material or a re even completely devitrified. Accordingly, Andisols in the Vosges ar e Like those of non-volcanic, non-allophanic Andisols elsewhere in the world: their andic properties are weakly expressed and are caused by organo-metallic complexes associated with their upper organic-rich hor izons rather than by allophanes.