1,721,053 research outputs found
Analisi lepidocronologica e fenologica della prateria a posidonia a nord della costa ionica calabrese
No full textAccumulation of trace elements in the peripheral and central parts of a foliose lichen thallus
No full textTotal concentrations of Al, As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Mo, Ni, Pb, Sb, and Zn were compared in the peripheral (younger) and central (older) part of the thallus of the epiphytic lichen Parmelia caperata from a background area of central Italy. The results showed that the trace element content was highly variable. Concentrations were similar for several elements (As, Cr, Fe, Hg, Mn, Ni, Sb). Elements of limited metabolic significance (Al, Cd, Pb) had higher concentrations in the central parts, suggesting that they are trapped in the medulla, while elements essential for lichen metabolism (Co, Cu, Mo, Zn) had higher concentrations in the peripheral parts, suggesting that they are easily displaced from one part of the thallus to another
Mercury, Lead and Copper in Feathers and Excreta of Small Passerine Species in Relation to Foraging Guilds and Age of Feathers
No full textIn the present study excreta and feathers of five species of adult passerine birds from Montepulciano wetland (Siena, Italy) were assayed for trace elements between January and August 2006. Lead concentrations varied from 16.31 to 26.50 mg/kg and were found strictly related to the age of feathers. Copper levels were found to be high mainly in insectivorous birds (9.68 mg/kg) and were probably influenced by local use of copper-based agricultural fungicides. Mercury accumulation in feathers varied between species from 0.08 to 0.73 mg/kg. The role of feeding habits on trace elements levels in feathers and excreta is discussed. © 2009 Springer Science+Business Media, LLC
Heavy metals in two colonies of Otaria flavescens (order Pinnipedia) on the coast of Argentina
No full textValutazione preliminare di rischio tossicologico nella Laguna di Lesina utilizzando alcuni biomarkers
No full textIndagine preliminare sulla contaminazione da Pb di origine venatoria nella Riserva Naturale provinciale del Padule "Diaccia Botrona" (GR)
No full textPosidonia Oceanica come bioindicatore per elementi in tracce: analisi dell'eandamento temporale mediante l'uso della lepidocronologia
No full textDeposition, abatement and environmental fate of pollutants in urban green ecosystems: Suggestions from long-term studies in Siena (Central Italy)
No full textLong-term biomonitoring of atmospheric pollutants in Siena shows that organisms in urban ecosystems are an overlooked source of information on the deposition and environmental fate of chemicals that are not measured by automatic monitoring devices. Quercus ilex leaves and epiphytic lichens intercept airborne particulates and can be used as reliable quantitative biomonitors of metal deposition. Soils beneath holm oak trees have an enhanced sink capacity for metals and a noteworthy faunal diversity. Earthworms and land snails inhabiting those soils can help to evaluate metal bioavailability, their potential trophic transfer and health risks. Biological crusts, mosses and mollusks from vegetated urban walls appear even more reliable biomonitors of metal deposition. Although Siena is a town with its own architectural and climatic features and moderate atmospheric pollution mainly caused by vehicular traffic and domestic heating, our overview offers suggestions and guidance that can be adapted across different urban contexts, for enhancing the role of urban green ecosystems in the abatement and monitoring of atmospheric pollutants. Comparisons among the capabilities of different tree species to improve urban air quality indicate that in Mediterranean towns it would be difficult to select a better alternative to Q. ilex, although this species emits VOCs and contributes to O3 formation, a pollutant now of major concern. Due to the decreased atmospheric concentrations of SO2 and the scarce sensitivity of lichens to O3, in many towns lichen biodiversity seems no longer a valid indicator of air quality
Passive monitoring of trace elements with tree leaves, epiphytic licherns and bark substrate
No full textTotal concentrations of Al, Cu, Fe, Hg, Mn, Mo and Zn in the epiphytic lichen Parmelia caperata, substrate bark and leaves of oaks (Quercus cerris and Q. pubescens) from a background area in Tuscany (central Italy) were compared. The elemental composition of unwashed samples, especially bark, was clearly affected by soil dust contamination, thereby leading to incorrect interpretations of baseline concentrations and relationships between elements. The normalization of total element concentrations to the surface soil composition (digested and analyzed by the same procedures), using Al as reference element, gave more reliable baseline values and allowed comparison between different biomonitors. The suitability of lichens, leaves and barks for studying the environmental distribution of trace elements in terrestrial ecosystems is discussed
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