Search results for "PEDOGENESI"
showing 4 items of 44 documents
Pedogenesis in disturbed alpine soils (NW Italy)
2002
In alpine environments, natural or man-induced disturbances are fairly common and acknowledged as determining factors in pedogenesis and soil distribution. We have selected a representative alpine valley in the Italian Northwestern Alps to evaluate the effects of perturbations of different intensity and frequency on soil development and weathering during the last few centuries. In order of decreasing disturbances, we selected: (i) an active avalanche shoot; (ii) a man-built terrace; (iii) a park-like forest; and (iv) a coniferous forest. In the two most disturbed sites, independently of the intensity and frequency of the disturbances, the active pedogenic processes are restricted to the top…
Tracing the source of gypsum in New Caledonian soils by REE contents and SSr isotopic compositions
1998
Gypsum minerals forming in pedogenic environments in New Caledonia were examined for their S and Sr isotope compositions and REE distributions. Three possible sources were identified: volcanic, soil-derived and marine. However, differentiation based only on the REE contents and normalized patterns was not possible, but, the best preserved volcanic sample yields a negative EuEu∗ anomaly and the lowest GdNYbN ratio due to the high content of organic matter. Mixing calculations of the δ34S values and 87Sr86Sr ratios confirmed that the marine gypsum has a δ34S value close to + 21‰ and an 87Sr86Sr ratio close to 0.70912, and that the volcanic gypsum has a δ34S value of 0‰ and an 87Sr86Sr ratio o…
Approche d'un territoire de montagne : occupations humaines et contexte pédo-sédimentaire des versants du col du Petit-Saint-Bernard, de la Préhistoi…
2014
As part of a multi-year programme, survey campaigns have been carried out on both slopes of the Petit-Saint-Bernard pass (2188 m, western Alps), at an altitude of between 750 and 3000 m. The method employed abandons ground-based surveying in favour of multiple manual surveys carried out on selected topographic contexts down to the base of the Holocene fill. The results obtained document the longterm development of the pedo-sedimentary dynamic and the occupation of the different altitude stages. The significance of the archaeological data collected is discussed in relation to the state of knowledge in a comparison area including the neighbouring valleys of the western Alps, to existing settl…
Variazioni di carbonio organico nei suoli italiani dal 1979 al 2008
2010
I suoli contengono circa tre volte la quantità di carbonio disponibile a livello mondiale nella vegetazione e circa il doppio di quella presente in atmosfera. Tuttavia il carbonio organico del suolo (SOC) si è ridotto in molte aree, mentre è stato rilevato un aumento della CO2 atmosferica. Ricerche recenti hanno dimostrato che sono stati i cambiamenti di uso e gestione del suolo a provocare le maggiori perdite di SOC nel recente passato, piuttosto che le più alte temperature e i cambiamenti delle precipitazioni conseguenti il cambiamento climatico. Lo scopo principale di questo lavoro è quello di stimare le variazioni del contenuto di carbonio organico dei suoli (carbon stock, CS) in Italia…