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International audience; This article is an as simple as possible key of classification of terrestrial (aerobic, not submerged) topsoils (organic and organic-mineral series of soil horizons). Based on the introduction exposed in Humusica 1, article 1, and using vocabulary and definitions listed in article 4, a classification is proposed for better understanding the biological functioning of the soil, partially disclosing the process of litter digestion. Five types of terrestrial topsoils, called terrestrial humus systems, are described and illustrated with the help of photographs. Within each humus system, 3–4 humus forms are also revealed, corresponding to similar series of soil horizons generated in a relatively homogeneous environment whose range of ecological factors is not so large to overstep and cause the genesis of another different humus system. The article ends with a figure that shows the relationship between Tangel and Amphi humus systems, and a dichotomous key of classification that one can easily print and bring in the field for practicing humus classification.

Rainfall-induced shallow landslides are hazardous phenomena that could cause several damages to infrastructures and people. To understand the hydrological and mechanical triggering conditions of shallow landslides in an area of Oltrepo Pavese (Northern Apennines, Italy) a field monitoring was conducted. In this work the results of 16 months monitoring are shown, focusing on the hydrological behaviour of the studied materials as function of rainfall and its effect on slope stability. Keywords Slope monitoring Shallow landslides Stability analysis Introduction Rainfall-induced

In a spruce forest of the Autonomous Province of Trento, located on an acid substrate and with a north exposition, within the Village of Pellizzano, a transect has been traced; along this transect 19 humus profiles have been examined, one at every three meters. For each of them, OH and A horizons (respectively the humic organic and the organo-mineral horizon) have been sampled and studied following the methodology formulated by Ponge (1984) and Bernier & Ponge (1994). The morphological and semi-quantitative observation of these horizons with the stereoscope and the use of an identification key of soil fauna’s faecal pellets (Galvan et al. 2005) allowed us to determine and point out their relative abundance and to formulate interesting remarks on spatial and temporal variability of humus forms in forests. For four profiles of the transect, a micro-morphological study, with the microscope, of the thin sections of every horizon has been carried out as well, in order to observe those more detailed characters such as: the presence of fossilized coprolites, of paleo-aggregates and of those soil fauna’s dung, in particular mites’ faecal pellets, hardly identifiable with the stereoscope. Both methodology of morphological investigation proved to be necessary for an accurate research and to be a substantial aid for a better identification of humus forms, after they have been described in field following the French morphological-genetic approach (Jabiol et al. 1995).

Le frane superficiali indotte da piogge intense e concentrate sono annoverabili tra i fenomeni franosi che causano il maggior numero di danni. Al fine di identificare, a scala di versante, i processi idrologici e geotecnici che controllano il loro innesco è stata installata una stazione sperimentale in un’area campione dell’Oltrepo Pavese per il monitoraggio del contenuto in acqua del terreno, della pressione interstiziale negativa, delle precipitazioni, della direzione ed intensità del vento e della radiazione netta. Il lavoro presenta i risultati preliminari ottenuti nel corso dei primi mesi di monitoraggio.