Summary
Drought‐induced tree mortality frequently occurs in patches with different spatial and temporal distributions, which is only partly explained by inter‐ and intraspecific variation in drought ...tolerance. We investigated whether bedrock properties, with special reference to rock water storage capacity, affects tree water status and drought response in a rock‐dominated landscape.
We measured primary porosity and available water content of breccia (B) and dolostone (D) rocks. Saplings of Fraxinus ornus were grown in pots filled with soil or soil mixed with B and D rocks, and subjected to an experimental drought. Finally, we measured seasonal changes in water status of trees in field sites overlying B or D bedrock.
B rocks were more porous and stored more available water than D rocks. Potted saplings grown with D rocks had less biomass and suffered more severe water stress than those with B rocks. Trees in sites with B bedrock had more favourable water status than those on D bedrock which also suffered drought‐induced canopy dieback.
Bedrock represents an important water source for plants under drought. Different bedrock features translate into contrasting below‐ground water availability, leading to landscape‐level heterogeneity of the impact of drought on tree water status and dieback.
During the last recent years, in Quinis, a small village sited in the Alta Val Tagliamento valley (Friuli Venezia Giulia Region, NE Italy), the inhabitants faced with instability phenomena related to ...the presence of soluble rocks in the subsurface. The evaporite bedrock is mainly mantled, in fact, by high thickness deposit. This paper explains the methodological approach that we used to identify the instabilities in a very complex geo-structural environment where the urbanization limits the applicability of several investigation techniques. Different methods were used to define the bedrock morphology, to characterize the mantling deposits and to identify the processes behind. What emerged from the study is a mandatory multidisciplinary approach to characterize the subsoil, because each technique is not able individually to take to a unique result. The data collected allowed to draft a geo–hydrogeological conceptual model of the Quinis village.
The lessons learned, even if with some site-specific dependency, demonstrate the importance of broad-spectrum investigations, which are essential to understand the subsurface characteristics avoiding relevant socio-economic impact and supporting an adequate future territorial planning.
•The importance of a multidisciplinary approach in the sinkhole study.•Maximum subsidence occurs while the water table lowering.•GPR surveys record the ongoing subsidence analyzing the asphalt.
Although karst aquifers are highly vulnerable and represent an important water resource, they are often inadequately protected. Furthermore, national water resource protection policies lack precision ...regarding the criteria for delimitation of source protection zones in karst. Usually either vulnerability assessment or travel time is considered. The proposed integrated protocol considers both. It is specifically designed for large karst aquifers where i) an additional distinction between areas of different liability to contamination within the aquifer, and ii) a certain generalisation of protection classes should be made for practical reasons. The protocol includes a detailed description of the separate steps of the protection zoning procedure. Information obtained from both artificial and natural tracers is used to account for the variability of groundwater flow under different hydrologic conditions. Analysis of groundwater physico-chemical parameters time series is better employed under high flow regimes and analysis of artificial tracers breakthrough curves under low flow conditions. Source protection zones are divided into three levels of protection, which should be further generalised, validated and adjusted to land use plans. The protocol has been applied to the Classical Karst Region transboundary aquifer (NE Italy and SW Slovenia). The results enable a uniform delineation of protection zones encompassing water sources that have not been protected to date, and improve the understanding and management of transboundary aquifers. The proposed protocol can be used in other karst aquifers, and adjusted to national protection legislation and spatial planning frameworks.
We present the first detailed survey of tidal notches in the central Mediterranean area, in particular along the coastline of Gozo and Comino (Malta). The Maltese Islands represent one of the few ...sites in the Sicily Channel which exhibits coastal carbonate rocks. Marine notches on the islands of Gozo and Comino were surveyed by means of a seven day continuous snorkeling survey around the entire perimeter of the two islands. We surveyed the occurrence, lack and typology of marine notches and we correlated them with late Holocene sea level changes. Sea temperature (T) and electrical conductivity (EC) were collected along the route in order to locate the submarine springs and to relate them to the surveyed notches.
A well-carved continuous roof notch was discovered along most of the plunging cliffs. It is well-carved out, in particular along the northern and western coast of Gozo. It develops from about 0.2 m above the mean sea level down and it can be up to 1.5–2 m deep. On the contrary, tidal notches are localised only in 8 sites. In 2 sites, Vermetid trottoirs develop at low tide level. In addition, at about −7 m to −10 m m.s.l., a 2–5 m wide marine terrace develops along extensive tracts of plunging cliffs, always in correspondence with the roof notches. This submerged terrace seem to be the result of the late Holocene slowdown of the sea level rise, which started to smooth the terrace and to carve out the submerged part of the roof notch, thanks to the exposed location of the islands and the favourable lithology.
Through the collection of hydrological data, the presence of 21 submarine springs were detected. They occur mainly in the south-western coast of Gozo and on eastern coast of Comino. Anyway, marine notches seem not to be related to the freshwater outflow, such as those in the Adriatic Sea, because the studied islands are very exposed. As a consequence, along the Maltese islands bioerosion seems to be the most effective process in notch development.
The dramatic climatic and environmental changes that occurred at the end of the last glaciation led to the formation of landforms (e.g., moraines, fluvial ridges, and alluvial terraces) that strongly ...characterize the landscape in the alluvial plains facing the Alps. This also occurred with the Tagliamento glacier, which built a large LGM moraine amphitheatre in the piedmont sector of the southeastern Alps and fed fluvioglacial systems in the Friulian plain (NE Italy). The Cormor stream was one of the main glacial outwashes and formed an alluvial megafan during the peak of the LGM. At the decline of the LGM, the active belt narrowed and was subsequently abandoned. Since the Lateglacial the Cormor system has been an intermittent stream with limited activity. This sequence of events led to the preservation of large LGM surfaces, which enables their investigation, along with correlatable moraine ridges. The study of megafan depositional phases allows us to precisely constrain the chronology of glacial withdrawal at the end of the LGM, which is difficult in large sectors of the southern Alps.
The geomorphological and geological study of the Cormor megafan was realized through the use of remote sensing, DEM analysis, field survey, stratigraphic boreholes, and radiocarbon dating. During the peak glaciation of the LGM, the Cormor experienced widespread aggradation with gravel deposition up to 15–25km from the megafan apex, while the distal sector was dominated by fine-grained sediments. At the end of the LGM the Cormor stream incised the apical portion of its megafan, funnelling the sedimentary discharge and experiencing a limited aggradation in the distal sector with the formation of a progradational lobe. This deposition buried some swampy areas, sealing peaty and organic-rich clayey horizons with 2–4m of sediments. The top of these layers is radiocarbon dated at 22.0–19.5kacal BP and indirectly constrains the chronology of several recessional moraines that formed within the glacial amphitheatre.
After this depositional phase, the Cormor megafan was deactivated because of water and sediment discharge concentration of the Tagliamento catchment in the Tagliamento River. This study demonstrates the possibility to reconstruct the timing of the decline of the Tagliamento moraine amphitheatre by studying the distal portion of the related outwash plain. Moreover, new geochronological dating allows chronological comparison of the glacial withdrawal in the eastern sector of the Southern Alps with the global chronology. The results suggest that we can apply this approach also in the distal part of the other alluvial megafans formed by Alpine glacial outwashes in the central part of the Po plain where radiocarbon chronology is almost lacking.
We provided new data on topography, morphology and physical/chemical parameters (pH, T, NO2-, Ca2+, PO43-, NaCl) collected in several shore grykes along the Northwestern Istrian coast, between ...Savudrija and Zambratija. Six transects, eachcontaining four to five pools, have been surveyed. Three morphological zones have been identified along the selected profiles. Morphological features of the shore grykes along the western Istrian coast are, in fact, closely related to the local tide. High-level pools are affected by karstic processes, and the surface is usually smooth. At their bottom, terrigenous deposits, mainly terra rossa, occur. Seaward, bioerosion prevails and at the bottom of the grykes, sand and rounded pebbles have been found. Chemical/physical parameters suggest that grykes located at lower altitudes are affected by seawater factors, while pools located at increasing altitudes are affected mainly by rainfall and consequentially freshwater or saltwater remaining from rainfalls or storm events. Shore gryke genesis is strongly controlled by geological weakness, along whichthey develop. Their origin is in fact due to local tectonics, while their development is related to the active vertical tectonic subsidence of the study area. Pools located at higher altitudes are mainly affected by solution karst processes, but due to the tectonic downdrop of the area, when the grykes come in contact withsea, they are gradually shaped by marine processes.
The genesis and development of the submerged notch occurring along the Northern Adriatic limestone coasts, surveyed at depth ranging between −0.35 and −2.8
m and amplitude consistent with the local ...tide is discussed using new and published data on its elevation and data on limestone lowering rates, collected using a micro-erosion meter and a traversing micro-erosion meter. Coastal limestone lowering rates in the Northern Adriatic range between 0.008 and 1.170
mm/y and they are about eight times higher than inland limestone lowering rates. Data support the hypothesis that notch is presently carving, even if no present-day notch has been surveyed in the area.
The lack of a modern notch, and the presently submerged notch position, could be related to (1) a rapid still-acting tectonic downdrop or (2) an increase in weathering/erosion rates causing by different environmental conditions, e.g. during the so-called Medieval Warm Period, marked by more aggressive weathering, both chemically, biologically and/or mechanically, than present conditions, due to an increase in rainfall or variations in the acidity of seawater. Pros and cons of these hypotheses are discussed in the paper.
The paper aims to present the geology of the western part of the Classical Karst (NW Dinarides), located at the border between Slovenia and Italy. The work is based on archive, published and new data ...collected by Slovenian and Italian researchers within several scientific national and Cross Border Cooperation projects. The map, produced at a scale of 1:50,000, summarizes the lithological and structural setting and is supplemented by three geological cross-sections of the study area.
The paper aims to describe and map the geomorphological and lithological features of the Gulf of Trieste and its eastern coasts and to define its neotectonic behaviour by means of the analysis of the ...morphoneotectonic evidence. The final map, produced at a scale of 1:30,000, shows the outcome of field investigations carried out along the coast and the sea bottom and a detailed geomorphological classification of the coastline. Published and new data coming from the analysis of archaeological remains, geomorphological and sedimentological sea-level indicators and geophysical researches are discussed in order to provide a complete overview of the study area.
This paper is aimed at mapping the submerged notch along the northeastern Adriatic coast and discussing the relations between the submerged notch, the seawater, the groundwater and the freshwater ...discharge along the coasts of the study area. Using hydrological and observational data collected during a solitary snorkel-swimming expedition along similar to 250 km-long route along the Istrian coasts and thermal and topographical data, we discuss the hydrogeological and topographical constraints on the origin and development of the submerged notch in the northeastern Adriatic Sea. The submerged notch was surveyed at depths ranging between -0.6 m m.s.l. and -2.6 m m.s.l. in the northern sector of the Gulf of Trieste (Italy), and at about -0.5/-0.7 m m.s.l along the Limski channel (Croatia). Along the Savudrija peninsula, a slightly carved submerged notch was surveyed at -0.5/-0.6 m m.s.l. The modern notch is completely lacking in the study area. Topographical data highlight that the submerged notch occurs in correspondence of plunging cliffs. Moreover, the submerged notch developed in correspondence of the submarine springs that allow mixing-zone dissolution. Data suggest that the mixing-zone dissolution, caused by the freshwater from submerged springs or from the largest rivers in the Gulf of Trieste, was a major factor in developing submerged notches. These new observations provide basic data for future studies on the development of the submerged notch along the northeastern Adriatic coast, previously linked almost exclusively to bioerosion.
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