Salinity and periodic inundation controls on the soil‐plant‐atmosphere continuum of gray mangroves

Salinity and periodic inundation are both known to have a major role in shaping the ecohydrology of mangroves through their controls on water uptake, photosynthesis, stomatal conductance, gas exchanges, and nutrient availability. Salinity, in particular, can be considered one of the main abiotic regulating factors for halophytes and salt‐tolerant species, due to its influence on water use patterns and growth rate. Ecohydrological literature has rarely focused on the effects of salinity on plant transpiration, based on the fact that the terrestrial plants mostly thrive in low‐saline, unsaturated soils where the role of osmotic potential can be considered negligible. However, the effect of salinity cannot be neglected in the case of tidal species like mangroves, which have to cope with hyperosmotic conditions and waterlogging. We introduce here a first‐order ecohydrological model of the soil/plant‐atmosphere continuum of Avicennia marina—also known as gray mangrove—a highly salt‐tolerant pioneer species able to adapt to hyperarid intertidal zones and characterized by unique morphological and ecophysiological traits. The A. marina's soil‐plant‐atmosphere continuum takes explicitly into account the role of water head, osmotic water potential, and water salinity in governing plant water fluxes. A. marina's transpiration is thus modeled as a function of salinity based on a simple parameterization of salt exclusion mechanisms at the root level and a modified Jarvis' expression accounting for the effects of salinity on stomatal conductance. Consistently with previous studies investigating the physiology of mangroves in response to different environmental drivers, our results highlight the major influence of salinity on mangrove transpiration when contrasted with other potential stressors such as waterlogging and water stress.     

Seismic-induced rockfalls and landslide dam following the October 30, 2016 earthquake in Central Italy

On October 30, 2016, a seismic event and its aftershocks produced diffuse landslides along the SP 209 road in the Nera River Gorge (Central Italy). Due to the steep slopes and the outcropping of highly fractured and bedded limestone, several rockfalls were triggered, of which the main event occurred on the slope of Mount Sasso Pizzuto. The seismic shock acted on a rock wedge that, after an initial slide, developed into a rockfall. The debris accumulation blocked the SP 209 road and dammed the Nera River, forming a small lake. The river discharge was around 3.6 m³/s; the water overtopped the dam and flooded the road. By a preliminary topographic survey, we estimated that the debris accumulation covers an area of about 16,500 m², while the volume is around 70,000 m³. The maximum volume occupied by the pre-existing talus mobilized by the rockfall is about 20% of the total volume. Besides blocking the road, the rockfall damaged a bridge severely, while, downstream of the dam, the water flow caused erosion of a road embankment. A rockfall protection gallery, a few hundred meters downstream of the dam, was damaged during the event. Other elastic nets and rigid barriers were not sufficient to protect the road from single-block rockfalls, with volumes around 1–2 m³. Considering the geological and geomorphological conditions, as well as the high seismicity and the socioeconomic importance of the area, a review of the entire rockfall protection systems is required to ensure protection of critical infrastructure and local communities.     

Il cloruro di sodio nella polvere atmosferica di Venezia

Riassunto Raccolta con un metodo molto semplice, venne analizzata la polvere atmosferica di Venezia in diverse località ed in condizioni diverse di tempo. La quantità di sale trovata viene posta in relazione col vento e con la pioggia.

---

Summary After having collected by a very simple method the atmospheric dust of Venice in different places and various conditions of weather, this was then analysed. The quantity of salt found in it is put into relation with the wind and rain.

---

Zusammenfassung Der Verf. berichtet über die Salzgehalt-Bestimmungen welche er, mit einem einfachen Verfahren, für den atmosphärischen Staub in verschiedenen Orten von Venedig und Umgebungen, sowie bei verschiedenem Wetter, durchgeführt hat. Die Engebnisse sind mit der Wind- und Niederschlag-Verteilungen verglichen und erläutert.

     

Nuovo contributo alla bioclimatologia di Venezia

Prof.Francesco Saverio Zanon, Direttore dell' Osservatorio Geofisico del Seminario Patriarcale di Venezia e della stazione meteo rologica dell' Ospedale al Mare del Lido.     

Sabbia e radiazione al lido di venezia

Riassunto Vengono esposti i caratteri delle variazioni di temperatura della superficie della sabbia al Lido di Venezia, desunti dalle osservazioni del tredicennio 1929–1941, per le quali si procede ad opportuni confronti con i dati dell'attinometro del Violle relativi al medesimo periodo.

---

Zusammenfassung Die Eigenschaften der Temperatur-änderungen der Sandoberfläche auf dem Strand vom Lido in Venedig werden angegeben und untersucht, gestüzt auf den Beobachtungen der 13 Jahre 1929–1941, welche mit den Ergebnissen der Strahlungsmessungen mit einem Violle-Aktinometer in derselben Periode verglichen und erlätert sind.

     

Multi-methodological investigation of kunzite, hiddenite, alexandrite, elbaite and topaz, based on laser-induced breakdown spectroscopy and conventional analytical techniques for supporting mineralogical characterization

Gem-quality alexandrite, hiddenite and kunzite, elbaite and topaz minerals were characterized through a multi-methodological investigation based on EMPA-WDS, LA-ICP-MS, and laser-induced breakdown spectroscopy (LIBS). With respect to the others, the latter technique enables a simultaneous multi-elemental composition without any sample preparation and the detection of light elements, such as Li, Be and B. The criteria for the choice of minerals were: (a) the presence of chromophore elements in minor contents and/or as traces; (b) the presence of light lithophile elements (Li, Be and B); (c) different crystal chemistry complexity. The results show that LIBS can be employed in mineralogical studies for the identification and characterization of minerals, and as a fast screening method to determine the chemical composition, including the chromophore and light lithophile elements.     

Microsismi prodotti da urti

Riassunto Due urti di una nave che si incagliò sulla sponda del canale della Giudecca in Venezia causarono microsismi che furono registrati dai sismografi dell'Osservatorio Geofisico del Seminario. Si determina la differenza in tempo fra i due urti, nonchè la velocità della nave ed il periodo delle onde microsismiche.

---

Zusammenfassung Zwei Stösse erzeugt durch das Stranden eines Schiffes am Ufer des Giudecca-Kanals in Venedig haben mikroseismische Erscheinungen hervorgerufen welche von den Sismographen des Geophysikalischen Observatoriums registriert wurden. Darüber werden u. a. die Zeitdifferenz zwischen den zwei Stösse, die Schiffsgeschwindigkeit und die Perioden der mikroseismischen Wellen bestimmt.

     

Osservazioni frigorimetriche al Lido di Venezia

Riassunto Richiamati brevemente i concetti fondamentali intorno al recente metodo frigorimetrico, e intorno agli strumenti di misura (catatermometro e frigorimetri), vengono presentati in tabelle e diagrammi i dati delle osservazioni frigorimetriche eseguite nell'anno 1940 nella stazione meteorologica dell'Ospedale al mare al Lido di Venezia. Queste vengono poi commentate e messe in relazione con i principii teorici della frigorimetria, osservando che le formule di Hill per il nostro clima hanno bisogno di essere modificate. I medesimi dati vengono poi riferiti alle condizioni climatologiche, e confrontati con i risultati di altre stazioni italiane ed estere.

---

Zusammenfassung Nach Erwähnung der Grundgedanken der neueren frigorimetrischen Beobachtungsverfahren und der diesbezüglichen Instrumente (Katathermometer und Frigorimeter) werden in Tabellen und Diagrammen die Ergebnisse dargestellt, welche in der meteorologischen Station des Krankenhauses am Lido von Venedig im Jahre 1940 gesammelt worden sind. Diese Ergebnisse werden dann diskutiert und in Zusammenhang mit den theoretischen Grundzügen der Frigorimetrie gebracht, worauf gezeigt wird, dass die Hillesche Formel für unser Klima einer Verbesserung bedürfen. Dieselben bioklimatischen Elemente werden dann auf die meteorologischen Bedingungen bezogen und mit den Ergebnissen von anderen italienischen und ausländischen Stationen verglichen.

     

Occurrence of palygorskite and sepiolite in upper Paleocene–middle Eocene marine deep sediments of the Lagonegro Basin (Southern Apennines—Italy): Paleoenvironmental and provenance inferences

A mineralogical and geochemical study of clay lithologies and a biostratigraphic analysis of the carbonates from the deep-sea Lagonegro Basin (Southern Apennines—Italy) have been carried out to deduce in general the provenance of clay sediments and their paleoenvironmental conditions and particular to recognize the signature of the Paleocene–Eocene climatic global warming. The analysed succession comprising a wide stratigraphic interval of the Sannio Unit, spanning between Albian to the upper Oligocene–lower Miocene, is exposed near Accettura and Stigliano villages. Eighteen clay samples were analysed by XRD, XRF, SEM, TG-DTA. Their age was framed by biostratigraphic analyses carried out on carbonate sediments. Mineral assemblage of the clay sediments includes quartz, carbonates (calcite and dolomite), feldspars (plagioclase and k-feldspars), hematite, randomly illite/smectite mixed layers with a low illite percentage, kaolinite, discrete illite–muscovite, chlorite, palygorskite and sepiolite. The low illite percentage in randomly illite/smectite mixed layers indicates low diagenetic conditions for the studied successions. These features are unique for the Cretaceous–Tertiary successions of the Lagonegro domain and are particularly significant for the preservation of the native mineralogical assemblage useful to determine the provenance and paleoenvironmental conditions of the clayey sediments. Palygorskite and sepiolite are concentrated in the upper Paleocene–middle Eocene stratigraphic interval and particularly in the upper part of the early Eocene—lower part of the middle Eocene (biozone of Blow P 9–12). Clay sediments rich in palygorskite and sepiolite show a higher P₂O₅ amount and a lower kaolinite percentage, compatible with warm and arid climatic conditions typical of the global warming event well recorded in the southern tethyan margin. Likely palygorskite and sepiolite formed in lagoonal environment in nearby carbonate platform margins and then they were transported into the Lagonegro Basin as indicated by the well developed habitus of palygorskite. During the Paleogene the Lagonegro Basin and the nearby carbonate platforms represented a key sector the southern paleodomains of the Tethys. The discovery of these minerals gives a contribution to the reconstruction paleoenvironmental conditions of the Tethian paleo-margin during the early–middle Eocene.