Inciepient soil in proglacial areas of the Maladeta massif (Central Pyrenees)

Only 87.9% of the Little Ice Age glaciers remain in the Maladeta massif (Central Pyrenees). This deglaciation has led to an increase in proglacial areas, allowing the development of new habitats. 86 samples of incipient soils were selected in this massif to study which variables have more influence on the development of incipient soils. Geochemical, microbiological and statistical analyses were carried out under the hypothesis that the time of deglaciation controls the evolution of these incipient soils. In these very incipient soils, the time of deglaciation does not seem to be a key factor that determines the development of the soils. Despitethis, the duration of the snow cover (strongly influenced by the topography) is a factor that explains the degree of development of the soils. Moreover, the percentage of silt content has been shown to give the soil a higher reactivity, water and nutrient retentioncapacity and greater stability. A pattern of biological succession was found, from bacteria as colonisers to fungi in subsequent stages, and finally to plants colonising the habitats. Finally, the impact of mountain tourism in the most transited sector of theMaladeta massif (the Aneto cirque) showed a high concentration of nitrate which favours primary productivity and increases the abundance of microorganisms.