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Mn, Zn, Ni, Cu, Pb and Cr from a steel industry were studied in soils from an alpine valley near Turin (NW Italy). Dusts fell onto the agricultural lands in the valley floor as first demonstrated by a lichens analysis. Soil analysis showed that total metals were often very high without differences between topsoils and deeper layers, except Pb. In order to assess the risky zones a geostatistical approach was considered, lacking the parameters needed for modeling and because of the complex terrain. A spatial dependence for several metals was detected, but isarithmic maps from Kriging showed that the fallout of these single elements was not uniform. From a multivariate analysis a linear combination of total metals was computed: its score, used as a global index, well described the spatial distribution of the fallout. An effect of the high mountain walls on the fallout peaks was then suggested. [ABSTRACT FROM PUBLISHER]

A lead soil contamination from a continuous point source near Turin (Italy) was examined. According to the Gaussian plume model the distance of maximum concentration at ground was estimated downwind an incinerator located in an agricultural and woodland area. The Relative Topsoil Enhancement (RTE) of lead, taken as a tracer of dust fall‐out, rose more than 600%, but not at the forecasted distances. A geostatistical approach confirmed that the RTE was spatially dependent and a Kriging map well described the soil pollution after a long term emission. [ABSTRACT FROM PUBLISHER]

Soil degradation by processes such as soil erosion, shallow landslides, debris-flows etc. is a significant problem in mountain areas, and is a crucial issue for natural hazard assessment in mountain areas. Several soil properties, among which are the liquid and plastic limits, i.e. moisture contents for which a soil passes from the plastic to liquid state (liquid limit, LL) and from the semisolid to plastic state (PL, plastic limit), have been proposed as indicators for soil vulnerability to degradation processes, both of natural and anthropogenic origin. In this research we investigated the liquid and plastic limits of the main soil groups of World Reference Base for Soil Resources (WRB) classification present in Aosta Valley (N–W Italian Alps) from a pedogenic perspective. In particular, we compared 1) soils at different stages of development; and 2) different genetic horizons. Our main aim was to provide and interpret data on soils' consistency and mechanical behavior that may be used as indexes for the assessment of soil vulnerability. Despite its relatively small area, the Aosta Valley is characterized by a wide range of soil types. Sixty-two soils with different profile evolution stages, representative of 7 WRB soil groups, were investigated and LL and PL in genetic horizons were studied at the soil type and genetic horizons level. In general, soil consistency was largely determined by the organic matter content (both in topsoils and organic matter-enriched subsurface horizons), but in spodic horizons and some C horizons a role of poorly crystalline and pedogenic iron oxides was observed too. Considering the vulnerability to consistency loss, that can result in erosion processes and overall soil degradation, surface horizons were generally less vulnerable, as could be expected on the basis of previous research, i.e. showed higher LL and PL values, than the deeper ones, generally characterized by a reduction of soil consistency. Therefore, topsoil could receive higher water inputs while still preserving their consistency and strength. This was not confirmed in Podzols, where the organic matter enrichment of spodic horizons determined a discontinuity in physical properties between the E horizons (more vulnerable) and the underlying, spodic ones. The same trend was observed for Calcisols with a deep cemented Bkm horizon. The research provided a novel overview on LL and PL in the common soil types present in the Alpine region, integrating the already existing research on topsoil vulnerability to degradation processes (erosion, consistency losses, losses of strength), and the regional soil database. The use of LL and PL as indicators of soil physical quality was approached with a pedogenic perspective, which might be helpful for a better definition of hazard assessment at the regional scale. [ABSTRACT FROM AUTHOR]

In mountain areas, economical activities related to milk processing represent both a key source of income and job opportunities. One of the main characteristics of cheese production is the seasonal variability in the volume of milk processed and wastewater production that tend to limit the capacity of ecosystems to absorb their inputs. In alpine environment, the scarcity of plain surfaces and the climatic conditions results in the need for high CW performances of variable nutrient inputs in different seasons. By evaluating a CW seasonal efficiency for dairy wastewaters in a mountain region (Aosta Valley-NW Italy), this research was aimed to understand how performances of nutrient removal could be affected by seasonal shift in temperature and loadings. Results indicate that the “irregularly shaped” CW, designed to fit the natural landscape, shows best organic removal efficiency in winter (93 and 96% mass removal for BOD 5 in summer and winter respectively), in presence of high organic loadings and low temperatures. Even if nitrate removal is more variable during seasons (71 and 33% mass removal in summer and winter respectively) and differently affected by environmental conditions, overall performance meet the need of high removal efficiency. [ABSTRACT FROM AUTHOR]

Abstract: Continuous measurements of snow temperature profiles may be a valuable tool to investigate occurrence and persistence of thermal conditions promoting the strengthening or weakening of the snow structure, with potentially important consequences on avalanche release. In this paper, automatic measurements of snow temperature profiles are analyzed based on an extensive dataset (67site-years) in Aosta Valley, Italy. The aims of this work are: (1) to highlight issues and uncertainties in the data and show appropriate data filtering that may be implemented by similar measurement networks; (2) to assess the impact of data filtering on temperature gradient calculation, and (3) to quantitatively describe the occurrence and duration of strong temperature gradients at the base of the snowpack and close to the snow surface that may lead to the formation of weak layers. Three main sources of uncertainty were identified and corrected: (1) errors in the data logging; (2) drifts in temperature measurements; and (3) a large bias in spring measurements due to snow melting and lack of contact between the sensor and the surrounding snow. We estimated that strong temperature gradients may account for as much as 25% of total gradients and the duration of these may be as long as 35days. The frequency of strong gradients was significantly higher at the snow surface than at the snowpack base. Hence, the importance of surface faceted crystals as potential weak layers in alpine snowpacks is highlighted. [Copyright &y& Elsevier]

The <2-mm size range in soils may contain aggregates as well as primary particles. We investigated the breakup of aggregates <2 mm after applying different chemical and physical agents to 10 samples. Mass-size distributions were obtained by combining wet sieving and x-ray centrifugation after five treatments: water dispersion, chemical dispersion, organic matter removal, physical dispersion, and all of the above combined. The <2-mm range was subdivided into 20 size classes and the fragment production was evaluated with respect to water dispersion. Cluster analysis helped identify similar fragmentation patterns among samples for each determination method. The effectiveness of the single methods differed considerably among samples. Only their combination resulted in pronounced permanent dispersion. An empirical effectiveness index was developed to provide a quantitative assessment of the overall effectiveness of each method. This index indicated that both organic and inorganic binding agents contribute to topsoil aggregation in the <2-mm size range. [ABSTRACT FROM AUTHOR]

Some indigenous fruit trees, in the drylands of southern Africa are worthy of interest because of their adaptation to environmental conditions prohibitive for traditional crops. Their fruits or their derivatives are traditionally used as an additional income by rural population, but little information is available about the properties of the soils that support their growth, although this information is necessary if the trees are subjected to sustainable domestication. Several soil properties are, however, to be considered as a whole and discriminant analysis provides a helpful tool to individuate the best conditions for the tree growth. Thirty-five soil samples were taken in areas where the trees naturally grow and produce, and the analytical data of the surface layer were used to relate soil properties to tree species. Four groups of trees were well separated using two discriminant functions that takes into account both the fertility characteristics (pH, organic C, N, texture, and properties of the exchange complex) and the Fe contents and distribution among the oxide forms. The discriminant functions allow a very acceptable reclassification of the data (more than 80% of cases correctly reclassified) and the classification coefficients were used to build an empirical equation that may help to identify the most suitable tree to be introduced at a new site.. [ABSTRACT FROM AUTHOR]

Mountain vineyards are a valuable resource for high-quality wine production and landscape conservation. A suitability map (1: 50,000) for mountain vineyard cultivation was created for a study area located in Aosta Valley (NW Italy). We considered the following environmental variables that are known to influence wine production: slope, aspect, altitude and soil, producing a suitability map that allows the identification of areas that can be considered practical for sustainable mountain viticulture. [ABSTRACT FROM AUTHOR]

Abstract: The estimate of the effects produced by the impact of a snow avalanche against an obstacle is of the utmost importance in designing safe mountain constructions. For this purpose, an ad-hoc instrumented obstacle was designed and built in order to measure impact forces of small and medium snow avalanches at Seehore peak (NW Italian Alps). The structural design had to consider several specific and unusual demands dictated by the difficult environment. In this article, the new test facility is described from the engineering point of view, discussing the most important aspects of the analyzed problems which were solved before and after the construction. The performance of the instrumented obstacle in the first two operating seasons, and some proposals for future upgrading are eventually illustrated. [Copyright &y& Elsevier]

Abstract: Experimental test sites are important to understand the physical flow processes occurring within an avalanche. They can be at different scale: laboratory or real scale. In Europe, a dozen of real-scale test sites have been realized, though at present only a few of them are still operative. The primary goal is to measure avalanche dynamical variables under controlled conditions. Not all the observed phenomena have been fully understood yet and more work is needed especially regarding small to medium avalanches. The aim of this paper is to present a new experimental test site at a real scale in order to study specific topics: the dynamics of small and medium avalanches, the avalanche release processes and the interaction between avalanche flows and obstacles. The test site, called Seehore, is located in Aosta Valley in the North-western Italian Alps. The slope, with an elevation difference of about 300m (from 2300 to 2570m asl), has a mean slope angle of about 28°. Avalanches are artificially released on a routine basis to secure the ski-runs, as the site is located within a ski resort (Monterosa Ski); they are usually dense slab avalanches of small or medium size, but also a powder cloud may occasionally form. The site is instrumented with a steel obstacle, described in details in a companion paper, which measures the effects of avalanches impacting on it. Before, during and after each artificial release physical properties of the snow in the avalanche release, track and deposition zones are recorded; front velocity, erosion and deposition mass are estimated by field surveys or by videogrammetry and terrestrial laser-scan measurements. [Copyright &y& Elsevier]

Abstract: Terrace soils are distinctive features of the agricultural landscape in Europe. Due to their historical and aesthetic significance, they are a resource for agriculture and tourism: however they are also a challenge for land conservation and management. Nevertheless, the fundamental role of terrace soils for agricultural quality and natural hazard prevention has not been fully investigated. In the past, terraced slopes became ideal sites for human settlement and agricultural activities. At present, they are often used for high quality crops that grow on soils with specific chemical and physical properties. The filling material used for building terraces is a human-reworked substrate, where pedogenesis occurs under a strong human influence. This leads to soils with a generally limited pedogenic development and coarse texture, although, often, with good productivity. When abandoned, terraces are subjected to progressive decay due to erosion processes and slope failures. This review focuses on terrace soil properties, conservation and management in Southern Europe. In particular, it reports some examples from the northwestern Italian Alps, where terraced slopes are characterised by ancient origin and, presently, are subjected to specific practices for their preservation. The different effects of land degradation at hill slope scale may be mitigated through appropriate management practices favoring the terrace walls maintenance, drainage optimization, and the presence of a spontaneous vegetation cover. These subjects require careful planning and conservation measures that could be collected in “best practices” guidelines for farmers, landowners and decision-makers. [Copyright &y& Elsevier]

Abstract: Afforestation is one of the most invoked practices to compensate for CO2 emission to the atmosphere because of the high capacity of both the biomass and the soil to store C. This is accompanied by changes in the degradation and transformation of soil organic matter (OM). We investigated the changes in humic substances upon afforestation along an age sequence of 18-, 29-, 64-, 73- and 91-year-old Picea abies (L.) Karst. stands, planted on former agricultural land in Sweden. The forest floor was sampled by separating the Oi, Oe and Oa horizons; the mineral soil was sampled at 0–5 and 5–15cm depth. Humic acids (HA) and fulvic acids (FA) were extracted and quantified and the changes in HA composition over time were evaluated via characterization of lignin-derived phenols using CuO oxidation, in combination with chemical and spectroscopic analysis. The HA and FA contents in the organic horizons increased progressively with stand age up to 73years and then remained constant or even decreased at the oldest site. FA progressively dominated over HA with depth, suggesting translocation of the more mobile fraction from the organic horizons to the mineral soil. The HA composition changed with stand age. Elemental composition and 13C nuclear magnetic resonance (NMR) spectroscopy suggest an increase in the HA alkyl component with time, because of selective preservation of highly recalcitrant compounds from resins, waxes and other lipids, and resynthesis of aliphatic microbial products. The aromatic component increased up to 64years, and then decreased in both the organic horizons and the mineral layers, while lignin-derived phenols in the HA increased up to 29years and then decreased. In the youngest stands, the lignin composition of the HA in the organic horizons was determined from the input of tree-derived OM, while in the mineral soil the HA showed a greater content of syringyl and cinnamyl units, still bearing some characteristics of OM inherited from the former agricultural land use. With stand age, the acid/aldehyde ratio of vanillyl units [(Ac/Al)V] increased, indicating progressively greater lignin alteration. This resulted in incorporation of lignin-derived phenols into the humic material and leaching of highly oxidized products from the organic horizons into the mineral soil horizons. The latter likely was responsible for the loss of aromatic C from the HA after 64years and thus the selective preservation of alkyl structures. The translocation of altered lignin products to the mineral horizons and subsequent stabilization therein by association with mineral phases may account for the increase in C observed in the mineral layers of the oldest stands. [Copyright &y& Elsevier]

Abstract: Podzols often occur in association with organic soils along sequences governed by relief, with peats in depressions and podzols on slopes. The formation of bogs has also been described as a soil-induced process: the formation of cemented pans, impermeable to water, in highly developed podzols, enhanced the accumulation of organic matter and slowed down its decomposition. Humans may interfere with soil development, enhancing acidification and thus the eluvial phase of podzolisation, as it may be in the case of acid precipitation or of the plantation of conifers. The aim of this work was to study the transition between Spodosols and Histosols, in the Krkonoše National Park (CZ), where spruce has substituted the natural vegetation and acid precipitation has damaged several areas of the park. The soils were studied at two sites: one site is relatively preserved and soils (Spodosols and Inceptisols) develop on a steep slope. At the other site, a gently undulating mountain summit, Spodosols are associated to Histosols and the forest decline is more severe. Three Spodosols (Humic Haplocryod, Typic Cryaquod, Placic Cryaquod) and a Histosol were selected at the second site, and the soil properties and organic matter dynamics were compared to those of a Typic Haplocryod sampled at the first site. Profile morphology and chemical analyses indicated that podzolisation has been more intense at the second site, probably because of the differences in relief and in the amount of water available for pedogenic processes: a high accumulation of organic matter and thick Bhs horizons were the most striking differences, together with depletion in Fe from eluvial horizons. Moreover a trend in the chemical indicators of podzolisation was appreciated among the profiles sampled at the second site. The analyses of organic matter and humic substances indicated that, in Bs horizons, the organic matter characteristics were very similar in the two sites, but in the eluvial and organic horizons marked differences appeared. At the first site, the fulvic acids in the E horizons were small and oxidised, similar therefore to those found in the Bhs horizons, whereas at the second site fulvic acids became bigger, more aliphatic and less oxidised and were therefore less prone to migration. Some of these properties of organic matter were linked to soil water regime, others to the shift in vegetation from forest to grass cover and seemed therefore to be related to the soil evolution itself, being podzolisation in this sense a self-limiting process. Acid precipitation may however have played a role in the change of size of fulvic acids, which were very rich in sulphur, through C–S linkages. The complex interaction between natural and anthropogenic factors seemed to have decreased the ability of organic matter to migrate, enhancing the formation of Histosols. [Copyright &y& Elsevier]