An integrated approach to studying the genesis of andic soils in Italian nonvolcanic mountain ecosystems

Over recent decades, andic soils have been increasingly found in non-volcanic mountain ecosystems (NVME) inmany parts of the world. In Italy, this type of soil has proved to be greatly affected by aeolian deposits and to bewidely distributed geographically.However, there are still many open questions, especially regarding the genesis of these soils. This paperfocuses on five representative pedons taken from NVME. Soil forming processes and relationships between soiland underlying bedrock were investigated by using an integrated approach including geochemical, magnetic,mineralogical, micromorphological and particle size distribution (PSD) analysis. The 5 pedons showed andiccharacter and similar morphology and micromorphology (e.g. silt illuviation, pedorelicts), as well as largedifferences in terms of soil reaction and clay mineralogy. The analysis of the vertical distribution of C, Al and Feextracted in pyrophosphate along with related geochemical indices (e.g. Cp/Alp) enabled us to indicate andosolizationas the main process of soil formation and to exclude podzolization. With respect to the soil-bedrockrelationship, 2 soils showed great similarity to the underlying bedrock along with a clear aeolian particle sizedistribution footprint, whereas, in the remaining 3 soils, there was a clear soil-bedrock discontinuity and anevident volcanic fingerprint. Some of the soil-bedrock differences related to the geographical settings and latitude.