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In this study, leaves of the evergreen holm oak Quercus ilex were used to assess airborne contamination of potentially toxic elements (PTEs) at five towns located on the slopes of the Mt. Amiata (central Italy), an area with a long history of mining and, more recently, an important district for the industrial exploitation of geothermal energy. PTE composition and covariance of washed and unwashed Q. ilex leaves of three different ages (6, 12 and 24 month-old) were used to identify atmospheric inputs of PTEs at residential areas, evaluate long-term adsorption and retention of PTEs by the leaves, thus providing an indication of potential human exposure. Moreover, the determination of foliar concentrations of major elements (C, N, S and P) allowed an assessment of the nutritional status of the investigated urban tree stands which excluded the existence of stress condition caused by air pollution or other disturbances. Results indicated that overall Pb, Cu, and Cd concentration were low in the investigated urban sites, if compared with similar studies conducted in larger Italian cities, denoting a low contribution of vehicular traffic to the atmospheric pathway. The five urban settlements were characterized by a specific profile of elements (Al, Ba, Hg and Sb) enriched in unwashed leaves, resulting from the distinct geochemical characteristics of the area and from diffuse (i.e., urban activity) and point sources of PTEs emission (i.e., brownfields, geothermal power plants). The latter sources primarily govern the distribution of Hg, whose contamination was found to be very localized close to a major abandoned mining area. Our data provided quantitative evidence of the spectrum of PTEs potentially impacting resident population and may prove useful in support of follow-up instrumental monitoring campaigns of air quality, as well as for human health and ecological risk assessments. [ABSTRACT FROM AUTHOR]

Background and aims: Given that environmental factors like atmospheric CO2, temperature, and water availability will likely change simultaneously, it is difficult to make accurate predictions about future crop production. Effects of elevated CO2 or drought on aboveground plant growth are relatively well studied, while effects on the rhizosphere are rarely dealt with. The present work investigates the root exudation pattern of different osmotic protectants such as ions and sugars of two cultivars of barley grown under different water and CO2 levels. Methods: Barley (Hordeum vulgare L.) plants were grown in plant containers in climate chambers with an optimal and reduced water supply and two CO2 concentrations (380 and 550 ppm) and harvested at the stem elongation growth stage and when the inflorescences emerged. Results: The responses of root exudation to CO2 enrichment, watering level, and cultivar and their interactions varied with the developmental stage. While K+/Na+ ratio in root exudates remained stable at the stem elongation stage (DC30), it was higher at the booting stage (DC49) in the cv. "Bambina" than in cv. "Golden Promise". At DC30, in general the exudation of sugars, dissolved organic carbon (DOC) and their ratio (SUG/DOC) were lower at e[CO2] compared to ambient CO2 at normal watering conditions. Under reduced watering conditions, plants exuded on average 55% more sucrose than under well-watered conditions. The modern cv. BA exuded on average 53% more fructose than the older cv.GP. In contrast, at DC49, sucrose, DOC and SUG/DOC exudation were not affected by any factor. At e[CO2] plants exuded on average 39% less fructose than under ambient CO2. A water and CO2 interaction on glucose exudation was found at this stage. Under reduced water conditions, plants growing at ambient CO2 exuded less glucose but at e[CO2] exuded similar (GP) or even higher (BA) glucose levels than under normal water supply. Although drought and cultivar factors affected the root exudation of barley, the strongest effects in the exudation pattern were caused by CO2. Conclusions: This study presents a non-destructive percolation method for the collection of root exudates which can be used to give an insight into the complex interaction between global warming-associated environmental factors that cause yield losses and changes in crop quality and components of the belowground plant metabolism. [ABSTRACT FROM AUTHOR]

Background and aims: Given that environmental factors like atmospheric CO2, temperature, and water availability will likely change simultaneously, it is difficult to make accurate predictions about future crop production. Effects of elevated CO2 or drought on aboveground plant growth are relatively well studied, while effects on the rhizosphere are rarely dealt with. The present work investigates the root exudation pattern of different osmotic protectants such as ions and sugars of two cultivars of barley grown under different water and CO2 levels. Methods: Barley (Hordeum vulgare L.) plants were grown in plant containers in climate chambers with an optimal and reduced water supply and two CO2 concentrations (380 and 550 ppm) and harvested at the stem elongation growth stage and when the inflorescences emerged. Results: The responses of root exudation to CO2 enrichment, watering level, and cultivar and their interactions varied with the developmental stage. While K+/Na+ ratio in root exudates remained stable at the stem elongation stage (DC30), it was higher at the booting stage (DC49) in the cv. "Bambina" than in cv. "Golden Promise". At DC30, in general the exudation of sugars, dissolved organic carbon (DOC) and their ratio (SUG/DOC) were lower at e[CO2] compared to ambient CO2 at normal watering conditions. Under reduced watering conditions, plants exuded on average 55% more sucrose than under well-watered conditions. The modern cv. BA exuded on average 53% more fructose than the older cv.GP. In contrast, at DC49, sucrose, DOC and SUG/DOC exudation were not affected by any factor. At e[CO2] plants exuded on average 39% less fructose than under ambient CO2. A water and CO2 interaction on glucose exudation was found at this stage. Under reduced water conditions, plants growing at ambient CO2 exuded less glucose but at e[CO2] exuded similar (GP) or even higher (BA) glucose levels than under normal water supply. Although drought and cultivar factors affected the root exudation of barley, the strongest effects in the exudation pattern were caused by CO2. Conclusions: This study presents a non-destructive percolation method for the collection of root exudates which can be used to give an insight into the complex interaction between global warming-associated environmental factors that cause yield losses and changes in crop quality and components of the belowground plant metabolism. [ABSTRACT FROM AUTHOR]

The original article can be found online at https://doi.org/10.1007/s10653-022-01252-6. Correction to: Environ Geochem Health https://doi.org/10.1007/s10653-022-01252-6 In the original publication of the article, the first and last name of the fourth author was incorrectly published as "Loppi Stefano". [Extracted from the article]

After publication of the original article, the authors noticed an error concerning the ingredients of the used product Vizura®. The product does not contain a triazole, but a pyrazole as part of DMPP (3,4-dimethylpyrazolephosphate). [ABSTRACT FROM AUTHOR]

Background: The increasing demand for food and animal fodder worldwide has led to an intensified agriculture with an increasing use of nitrogen fertilizers. More recently, nitrate leaching and gaseous nitrogen emissions have become the focus of environmental discussions and climate politics. One approach to reduce such negative impacts is the use of nitrification inhibitors (NIs) that have shown to effectively reduce nitrogen losses to the groundwater and the air. However, ecotoxic effects of NIs have been studied to a limited extent only. Therefore, two commercial NIs (Piadin and Vizura) and an active ingredient of another NI, dicyandiamide (DCD), were assayed using various ecotoxicological biotests and test species: the Lemna Growth Inhibition Test (Lemna gibba), the Seed Germination/Root Elongation Toxicity Test (Agrostemma githago, Fagopyrum esculentum, Glycine max, Hordeum vulgare, Lunaria annua, Zea mays), the Seedling Emergence and Seedling Growth Test (A. githago, F. esculentum, Z. mays) and the marine Luminescent Bacteria Test (Aliivibrio fischeri). The fresh water L. gibba and the bacterium A. fischeri were exposed to different test concentrations in liquid growth media, whereas the terrestrial plants were exposed to the test substances diluted/dissolved in deionized water and added to the solid growth medium. Results: Dicyandiamide did not show ecotoxic effects in any test conducted. Piadin and Vizura showed ecotoxic effects throughout all experiments. Frond number and frond area of L. gibba were inhibited with increasing concentrations of both substances with Piadin leading to an earlier inhibition and therefore lower EC50 values. In the Seed Germination Test, Vizura generally inhibited seed germination and root development more effectively than Piadin. Regarding both substances, the endpoint root length was much more sensitive than the endpoint germination. In the Seedling Emergence Test, Z. mays was the least sensitive and the rare weed species A. githago the most sensitive species with regard to the tested endpoints and both substances. A. fischeri was strongly inhibited by Vizura, whereas Piadin had barely effects on the bacteria. Conclusion: All findings indicate ecotoxic effects of Piadin and Vizura, especially on the aquatic species L. gibba and on the root development of several terrestrial plant species. However, the origins of the ecotoxic properties remain unclear as both substances contain a mixture of—to some extent unknown—chemical compounds. [ABSTRACT FROM AUTHOR]