Time filter

Source Type

Cantonati M.,Museo delle Science | Cantonati M.,CNR Institute for the Dynamics of Environmental Processes | Lange-Bertalot H.,Goethe University Frankfurt | Lange-Bertalot H.,Senckenberg Institute | And 5 more authors.
Nova Hedwigia | Year: 2011

Mires are very selective habitats, and the colonisation by specifically adapted organisms makes them very important both for nature conservation and environmental education. They have, however, been threatened by different types of impacts. Our objective was to study diatoms in stations representative of the main typologies in the Site of Community Importance IT3230060 "Danta Mires", also to produce data for a management plan in the frame of a Life Project. Five shallow pools within different mountain mires were sampled in summer 2005 and morphologically and physicochemically characterized. The sampled sites cover a rather wide pH and TDS content gradient with very low nitrate and silica values. Diatoms were found to dominate in terms of numbers of taxa, followed by desmids, cyanoprokaryotes and filamentous green algae. In total, 86 diatom taxa, belonging to 35 genera, were found. As expected for acidic, low-mineralization waters the genera with the highest number of taxa were Eunotia and Pinnularia, followed by Encyonema, Cymbopleura, Gomphonema, and Nitzschia. The most frequent and abundant taxa were: Frustulia crassinervia, Nitzschia acidoclinata, Kobayasiella micropunctata, Encyonema neogracile, Brachysira brebissonii, Nitzschia perminuta, and Encyonema lunatum. Taxa abundant only in one or few sites were: Eunotia paludosa, Staurosira spinarum, Encyonopsis cesatii, and Achnanthidium minutissimum. Several rare taxa of special interest for their distribution and/or rarity could be found (e.g. Chamaepinnularia schauppiana, Cymbopleura incertiformis var. linearis, C. subapiculata, Eunotia lapponica, Microfissurata paludosa). On average, 17 taxa per site were found. The highest number (26) was found in a sediment sample taken in a site with special hydrochemical characteristics, and the minimum (11 taxa) in the sediment sample of the demolition materials dump mire. Diatom communities allowed characterising the mire pools studied as oligotrophic, acidic environments often affected by desiccation. On the basis of the autecology and distribution of the most frequent and abundant taxa, pH and hydroperiod appeared to be the most relevant environmental determinants. A striking result, also in view of eventual management consequences, was the very high proportion (72%) of rare and Red List taxa (including also species of the categories "Threatened with extinction", "Severely endangered", and "Endangered"). To preserve diatom biodiversity, these mires must be sheltered from uses other than recreational ones, and abrupt changes in hydrological regime and increases in nutrient input must be prevented. © 2011 J. Cramer in Gebr.

Gabrieli J.,University of Venice | Gabrieli J.,Environmental Protection Agency of Veneto ARPAV | Vallelonga P.,University of Venice | Vallelonga P.,Copenhagen University | And 14 more authors.
Environmental Science and Technology | Year: 2010

The occurrence of organic pollutants in European Alpine snow/ice has been reconstructed over the past three centuries using a new online extraction method for polycyclic aromatic hydrocarbons (PAH) followed by liquid chromatographic determination. The meltwater flow from a continuous ice core melting system was split into two aliquots, with one aliquot directed to an inductively coupled plasma quadrupole mass spectrometer for continuous trace elements determinations and the second introduced into a solid phase C18 (SPE) cartridge for semicontinuous PAH extraction. The depth resolution for PAH extractions ranged from 40 to 70 cm, and corresponds to 0.7-5 years per sample. The concentrations of 11 PAH were determined in dated snow/ice samples to reconstruct the atmospheric concentration of these compounds in Europe for the last 300 years. The PAH pattern is dominated by phenanthrene (Phe), fluoranthene (Fla), and pyrene (Pyr), which represent 60-80% of the total PAH mass. Before 1875 the sum of PAH concentration (∑PAH) was very low with total mean concentrations less than 2 ng/kg and 0.08 ng/kg for the heavier compounds (∑PAH*, more than four aromatic rings). During the first phase of the industrial revolution (1770-1830) the PAH deposition showed a weak increase which became much greater from the start of the second phase of the industrial revolution at the end of 19th Century. In the 1920s, economic recession in Europe decreased PAH emissions until the 1930s when they increased again and reached a maximum concentration of 32 ng/kg from 1945 to 1955. From 1955 to 1975 the PAH concentrations decreased significantly, reflecting improvements in emission controls especially from major point sources, while from 1975 to 2003 they rose to levels equivalent to those in 1910. The Fla/(Fla+Pyr) ratio is often used for source assignment and here indicates an increase in the relative contribution of gasoline and diesel combustion with respect to coal and wood burning from 1860 to the 1980s. This trend was reversed during the last two decades. © 2010 American Chemical Society.

Gabrieli J.,University of Padua | Gabrieli J.,Environmental Protection Agency of Veneto ARPAV | Gabrieli J.,University of Venice | Decet F.,Environmental Protection Agency of Veneto ARPAV | And 5 more authors.
Environmental Pollution | Year: 2010

PAH concentrations have been determined in 47 seasonal snowpack samples collected in the Valbelluna valley and in the Bellunesi Dolomites National Park, in the Italian North-Eastern Alps, during the winter of 2005. The ΣPAH concentration in high-altitude alpine sites (above 1700 m) was 32 ± 20 ng/kg while in valley bottom urban areas it was 165 ± 54 ng/kg with maximum values of 290 ng/kg. The GIS mapping technique was employed to produce a PAH spatial distribution. The urbanized Valbelluna valley, and in particular the SW part, had the highest accumulation of all PAH, with values an order of magnitude more than those in rural and alpine areas. This behaviour is consistent with urban air quality data, and is due to geo-morphological and meteorological factors such as the deeper shape of the valley at the position of the town of Feltre and the low altitude of the boundary layer during the winter season. © 2010 Elsevier Ltd. All rights reserved.

Loading Environmental Protection Agency of Veneto ARPAV collaborators
Loading Environmental Protection Agency of Veneto ARPAV collaborators