Prealpine Valley Research Articles

Metabarcoding reveals ecologically distinct fungal assemblages in river and groundwater along an Austrian alpine to lowland gradient.

Biodiversity, the source of origin, and ecological roles of fungi in groundwater are to this day a largely neglected field in fungal and freshwater ecology. We used DNA-based Illumina high-throughput sequence analysis of both fungal gene markers 5.8S and internal transcribed spacers region 2 (ITS2), improving taxonomic classification. This study focused on the groundwater and river mycobiome along an altitudinal and longitudinal transect of a pre-alpine valley in Austria in two seasons. Using Bayesian network modeling approaches, we identified patterns in fungal community assemblages that were mostly shaped by differences in landscape (climatic, topological, geological), and environmental conditions. While river fungi were comparatively more diverse, unique fungal assemblages could be recovered from groundwater, including typical aquatic lineages such as Rozellomycota and Olpidiomycota. The most specious assemblages in groundwater were not linked to the input of organic material from the surface, and as such, seems to be sustained by characteristic groundwater conditions. Based on what is known from closely related fungi, our results suggest that the present fungal communities potentially contribute to mineral weathering, carbon cycling and denitrification in groundwater. Furthermore, we were able to observe the effects of varying land cover due to agricultural practices on fungal biodiversity in groundwater ecosystems. This study contributes to improving our understanding of fungi in the subsurface aquatic biogeosphere.

Historical comparison of the damage caused by the propagation of a dam break wave in a pre-alpine valley

Study regionValle Camonica basin and Lake Iseo in the Italian pre-alpine and alpine region. Study focusThis paper provides the first hydraulic reconstruction of the terminal part of the Gleno dam break with the propagation of the flood wave along a wide pre-alpine valley. The reconstruction of this part of the event, accomplished with a new 2D Shallow Water Equations solver, provides the occasion to tackle some important issues related to the computation of flood damage, a topic of paramount practical importance for which there is no widely accepted procedure in the literature. New hydrological insights for the regionThe hydraulic reconstruction provides insights into the propagation of the flood through the floodplain as far as the inlet of Lake Iseo. A methodology for damage computation is presented that considers a physically based criterion for the vulnerability of human life, with significant implications with respect to the use of simpler approaches based only on the density of the population. The economic evaluation of the damage to the built environment and to agricultural activities is included through a comprehensive recent approach. We discuss the variations of the expected damage due to the hydraulic works accomplished over the last 100 years to decrease the flood hazard, showing that its reduction has been followed by an increase in the expected damage in the surrounding areas.

Fine-Resolution WRF Simulation of Stably Stratified Flows in Shallow Pre-Alpine Valleys: A Case Study of the KASCADE-2017 Campaign

In an overall approach aiming at the development and qualification of various tools designed to diagnose and/or forecast the flows at the local scale in complex terrain, we qualified a numerical model based on the WRF platform and operated in a two-way nested domain mode, down to a horizontal resolution of 111 m for the smallest domain. The area in question is the Cadarache valley (CV), in southeast France, which is surrounded by hills and valleys of various sizes. The CV dimensions (1 km wide and 100 m deep) favor the development of local flows greatly influenced by the diurnal cycle and are prone to thermal stratification, especially during stable conditions. This cycle was well documented due to permanent observations and dedicated field campaigns. These observations were used to evaluate the performance of the model on a specific day among the intensive observation periods carried out during the KASCADE-2017 campaign. The model reproduced the wind flow and its diurnal cycle well, notably at the local CV scale, which constitutes considerable progress with respect to the performances of previous WRF simulations conducted in this area with kilometric resolution, be it operational weather forecasts or dedicated studies conducted on specific days. The diurnal temperature range is underestimated however, together with the stratification intensity of the cold pool observed at night. Consequently, the slope drainage flows along the CV sidewalls are higher in the simulation than in the observations, and the resulting scalar fields (such as specific humidity) are less heterogeneous in the model than in the observations.

«Unhistoried and unconsidered». Percorsi di riscoperta e tutela tra Lario e Valtellina sulle orme di Edith Wharton e Bernard Berenson 1897-1912

The article examines the relationships between the description of some Lombard localities contained in Edith Wharton’s Italian Backgrounds (1905). In particular, attention is focused on the parallel events of rediscovery and conservation of the artistic heritage on Lake Como and in the pre-Alpine valleys between the publication of The Decoration of Houses (1897), the exhibition of sacred art at the Volta exhibition in Como (1899) and the preservation activity of Francesco Malaguzzi Valeri and Corrado Ricci. In addition, the essay examines the discovery of Renaissance painting in Valtellina (from Gaudenzio Ferrari to Cipriano Valorsa) by Bernard Berenson, hypothesizing that the American connoisseur may have been pushed on this research paths also thanks to Edith Warthon’s books and frequentation.

Estimating the snowfall limit in alpine and pre-alpine valleys: A local evaluation of operational approaches

The snowfall limit has important implications for different hazardous processes associated with prolonged or heavy precipitation such as flash floods, rain-on-snow events and freezing precipitation. To increase preparedness and to reduce risk in such situations, early warning systems are frequently used to monitor and predict precipitation events at different temporal and spatial scales. However, in alpine and pre-alpine valleys, the estimation of the snowfall limit remains rather challenging. In this study, we characterize uncertainties related to snowfall limit for different lead times based on local measurements of a vertically pointing micro rain radar (MRR) and a disdrometer in the Zulg valley, Switzerland. Regarding the monitoring, we show that the interpolation of surface temperatures tends to overestimate the altitude of the snowfall limit and can thus lead to highly uncertain estimates of liquid precipitation in the catchment. This bias is much smaller in the Integrated Nowcasting through Comprehensive Analysis (INCA) system, which integrates surface station and remotely sensed data as well as outputs of a numerical weather prediction model. To reduce systematic error, we perform a bias correction based on local MRR measurements and thereby demonstrate the added value of such measurements for the estimation of liquid precipitation in the catchment. Regarding the nowcasting, we show that the INCA system provides good estimates up to 6 h ahead and is thus considered promising for operational hydrological applications. Finally, we explore the medium-range forecasting of precipitation type, especially with respect to rain-on-snow events. We show for a selected case study that the probability for a certain precipitation type in an ensemble-based forecast is more persistent than the respective type in the high-resolution forecast (HRES) of the European Centre for Medium Range Weather Forecasts Integrated Forecasting System (ECMWF IFS). In this case study, the ensemble-based forecast could be used to anticipate such an event up to 7–8 days ahead, whereas the use of the HRES is limited to a lead time of 4–5 days. For the different lead times investigated, we point out possibilities of considering uncertainties in snowfall limit and precipitation type estimates so as to increase preparedness to risk situations.

PSI-based methodology to land subsidence mechanism recognition

Abstract. A methodology based on Persistent Scatterer Interferometry (PSI) is proposed in order to disentangle the contribution of different processes that act at different spatio-temporal scales in land subsidence (i.e. vadose zone processes as swelling/shrinkage of clay soils, soil consolidation and fluid extraction). The methodology was applied in different Italian geological contexts characterized by natural and anthropic processes (i.e. a Prealpine valley and the Po Plain in northern Italy).

Endocrinology and art. A goiter at the court of Theodolinda, queen of the Lombards: a fifteenth-century painting.

The Zavattari were a family of painters and stained-glass makers operating in Milan and western Lombardy during the fifteenth century. Franceschino Zavattari and his sons Gregorio and Giovanni were believed as the authors of a cycle of wall paintings—depicted between 1441 and 1446—in a chapel in the Monza Cathedral. The paintings, recently restored, tell the life of the founder of the cathedral, Theodolinda (ca. 570–628), queen of the Lombards. According to the legend, during a dream, a dove indicated the queen where she had to build a church dedicated to Saint John the Baptist, original nucleus of the cathedral [1]. A young bricklayer with a bi-nodular goiter is shown in the 34th scene of the cycle that portrays the groundbreaking ceremony of the church. It should be noted that during the fifteenth century, Italian stonecutters and bricklayers generally came from alpine and pre-alpine valleys set between Bergamo and Sondrio in the northern Lombardy [2]. In these areas, inhabitants often suffered from endemic goiter due to dietary iodine deficiency. Therefore, it comes as no surprise that an actual bricklayer with a thyroid disorder may have inspired the Zavattari in their work (see Fig. 1).

Partial separation of climatic niche between two cryptic species of Leptidea (Lepidoptera: Pieridae) in the Alpine–Adriatic region

Many cryptic species have been recently recognized in the European butterfly fauna, and climatic determinants have been investigated to explain the usually parapatric distribution of these species. Cryptic species of Leptidea, however, are often sympatric throughout Europe, with variable ecological interactions and segregation patterns. Focusing on the highly diverse landscape between the Alps and the Adriatic Sea, we evaluated the climatic and geomorphological correlates of the fine distribution of L. sinapis and L. juvernica, by means of discriminant analysis on 151 sites in a representative region. In addition to reliable records selected from collections and from the literature, we identified 104 specimens from 89 sites by analysing the morphometric variation of male and female genitalia and filtering for consistency between all alternative identification methods hitherto developed for this species complex. We found that L. sinapis is widespread from the coastal plain to the inner mountains, up to 1800 m above sea level (a.s.l.), whereas L. juvernica is restricted to the mountainous areas, inhabiting also the bottom of pre-alpine valleys, as low as 200 m a.s.l. Despite that the two species are often syntopic, L. juvernica is more frequent in areas with more intense rainfall and steeper slopes, whereas L. sinapis may occur in a broader range of conditions, also in warmer sites with a wider temperature range.

Ecological factors affecting plant species and travertine deposition in petrifying springs from an Italian ‘Natura 2000’ site

This study investigated ecological factors affecting species distribution and travertine deposition in an Italian site of the “Natura 2000” network. Vegetation plots were located along four streams in a prealpine valley (Valganna, Lombardy, Northern Italy). Five meso-scale variables (e.g. altitude, aspect and slope) and ten micro-scale variables (e.g. shading, plot position and soil accumulation) were recorded for each plot; in addition, travertine deposition was evaluated. The main floristic gradients extracted by DCA were related to topography, vegetation type and water availability. The occurrence of species groups in relation to environmental variables was analysed using Poisson regression. Amongst 15 environmental variables and six species, the variables showing the greatest relationship to travertine deposition were the length of the waterless period and substrate slope. Photosynthetic organisms had a minor role in travertine formation, mostly restricted to substrates with a shallow slope. The maintenance of a sufficient water flow is the most effective action in conservation plans for petrifying springs.

Soil slips and debris flows on terraced slopes

Abstract. Terraces cover large areas along the flanks of many alpine and prealpine valleys. Soil slips and soil slips-debris flows are recurrent phenomena along terraced slopes. These landslides cause damages to people, settlements and cultivations. This study investigates the processes related to the triggering of soil slip-debris flows in these settings, analysing those occurred in Valtellina (Central Alps, Italy) on November 2000 after heavy prolonged rainfalls. 260 landslides have been recognised, mostly along the northern valley flank. About 200 soil slips and slumps occurred in terraced areas and a third of them evolved into debris flows. Field work allowed to recognise the settings at soil slip-debris flow source areas. Landslides affected up to 2.5 m of glacial, fluvioglacial and anthropically reworked deposits overlying metamorphic basement. Laboratory and in situ tests allowed to characterise the geotechnical and hydraulic properties of the terrains involved in the initial failure. Several stratigraphic and hydrogeologic factors have been individuated as significant in determining instabilities on terraced slopes. They are the vertical changes of physical soil properties, the presence of buried hollows where groundwater convergence occurs, the rising up of perched groundwater tables, the overflow and lateral infiltration from superficial drainage network, the runoff concentration by means of pathways and the insufficient drainage of retaining walls.

Simulation of the circulation and related photochemical ozone dispersion in the Po plains (northern Italy): Comparison with the observations of a measuring campaign

[1] The atmospheric flow and pollutant dispersion over the Po plains in high-pressure conditions and weak synoptic circulation is investigated by means of a model simulation. This study stems from the work conducted during the Pianura Padana Production of Ozone (PIPAPO) campaign conducted in 1998. The typical mesoscale flow that establishes in the Po plains under these conditions is responsible for the diffusion of atmospheric pollutants in the prealpine valleys, their recirculation over the plain, and in general for the condition of stagnation and pollution buildup often found in the region. The model simulation presented here reproduces correctly the meteorological circulation that occurred in the central part of the Po valley during the PIPAPO first intensive observational period. The model results are compared with the measurements collected at a large number of surface observational sites and the airborne instruments deployed during the campaign. Subsequently, the diffusion and transformation process of the atmospheric pollutants is analyzed. Direct comparison with the measurements collected during the campaign indicates the good quality of the model results and the relevance of the conclusions deduced from the model simulation. This paper represents one of the few attempts made so far to simulate the circulation and photochemical ozone production over the Po plains.

Rapport entre karst et glaciers durant les glaciations dans les vallées préalpines du Sud des Alpes

Karst and glaciations in the Southern pre-alpine valleys. At least 13 glaciations occurred during the last 2.6 Ma in the Southern prealpine valleys. The glaciers scouring alpine and pre-alpine valleys had all the same feature, being valley temperated glaciers. Their tracks and feeding areas were always the same, just like the penological contents of their deposits. Contrary to previous assumptions until a few years ago, the origin of these valleys and of the lakes occupying the floor of some of them (Orta, Maggiore, Como, lseo, Garda Lakes ) is due to fluvial erosion related to Messinian marine regression. The valley slopes modelling is Messinian in age, too, while most caves are older. As a general rule, glaciers worked on valley slopes just as a remodelling agent, while their effects were greater on valley floors. The karstic evolution began as soon as the area was lifted above sea level (upper Oligocene -lower Miocene), in a palaeogeographical environment quite different from the present one, although the main valley floors were already working as a base level. During Messinian age, the excavation of deep canyons along pre-existing valleys caused a dramatic lowering of the base level, followed by a complete re-arrangement of the karstic networks, which got deeper and deeper. The Pliocene marine transgression caused a new re-arrangement, the karst network getting mostly drowned under sea level. During these periods, the climate was hot-wet tropical, characterized by a great amount of water circulating during the wet season. At the same time, tectonic upliftings were at work, causing breaking up of the karst networks and a continuous rearrangement of the underground drainage system. In any case, karstic networks were already well developed long before the beginning of Plio-Quaternary glaciations. During glaciations, karst systems in pre-alpine valleys could have been submitted to different drainage conditions, being : a) isolated, without any glacial water flowing ; b) flooded, connected to the glacier water-filled zone ; c) active, scoured by a stream sinking at glacier sides or in a sub-glacial position. The stream could flow to the flooded zone (b), or scour all the unflooded system long down to the resurgence zone, the latter being generally located in a sub-glacier position. The glacier/karst system is a very dynamic one : it could get active, flooded or isolated depending on endo-and sub-glacial drainage variations. Furthermore, glaciers show different influences on karstic networks, thus working with a different effect during their advance, fluctuations, covering and recession phases. Many authors believe, or believed, the development of most surface and underground karst in the Alps is due to glaciations, with the last one held to be mostly responsible for this. Whatever the role of glaciers on karstic systems, in pre-alpine valleys caves, we do not have evidence either of development of new caves or of remarkable changes in their features during glaciations. It is of course possible some pits or galleries could have developed during Plio-Quaternary glaciations, but as a general rule glaciers do not seem to have affected karstic systems in the Southern pre-alpine valleys with any remarkable speleogenetic effects : the glaciers effects on them is generally restricted to the transport of great amounts of debris and sediments into caves. The spotting of boulders and pebbles trapped between roof stalactites shows that several phases of in-and out-filling of galleries occurred with no remarkable changing in pre-dating features , including cave decorations. The presence of suspended karst systems does not prove a glacial origin of the valleys, since most of them pre-date any Plio-Quaternary glaciation, as shown by calcite cave deposits older than 1,5 Ma. The sediments driven into caves might have caused a partial or total occlusion of most galleries, with a remarkable re-arrangement of the underground drainage system. In caves submitted to periglacial conditions all glaciations long, we can find deposits coming from weathered surface sediments, sharp-edged gelifractbn debris and, more rarely, alluvial deposits whose origin is not related to the circulation of the glacial meltwater. In caves lower than or close to the glaciers limit we generally find large amounts of glacier-related deposits, often partly or totally occluding cave galleries. These sediments may be directly related to glaciers, i.e. carried into caves by glacial meltwaters, resulting from surface glacial deposit erosion. They generally show 3 dominant fades : A) lacustrine deposits B) alluvial deposits and C) debris flow deposits fades. The only way of testing the soundness of the forementioned hypothesis is to study the main characters and spreading of cave sediments, since they are the only real data on connection of glaciers to endokarst networks.

Sommersmog aus der Sicht der Atmosphärenchemie

The objective of the Swiss resarch project POLLUMET (POLLUtion and METeorology) is to investigate the formation and transport of photooxidants over the Swiss Plateau and in the surrounding pre-Alpine valleys. Extensive meteorological and air chemistry measurements were obtained during three intensive field studies conducted in the month of July of the years 1990, 1991 and 1993. The study included ground-based measurements, observations from instrumented aircraft, measurements taken with radiosondes, radars and other surface and airborne instruments. The comprehensive database is aimed to provide the information needed for the application of photochemical models and their evaluation and refinement. In order to better understand the photochemical processes which control ozone formation over the Swiss Plateau, calculations with the Harvard Photochemical Model and the Harwell Photochemical Trajectory Model were conducted and compared with experimental data. Reduction scenarios performed with both models yield in one case a NOx-limited situation for rural areas, whereas the other model predicts a transition type situation. Hydrogen peroxide was used as an indicator to study the performance of the photochemical models. Combining measurements of ozone, NO2 and hydrogen peroxide indicates that ozone in rural areas might be reduced most effectively by NOx controls. The model results indicate, that in Switzerland emissions have to be reduced by a large amount to achieve a substantial reduction in peak values of surface ozone.