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The aim of this study was to estimate the contribution of submicronic (PM1) and coarse (PM > 1) particulate matter deposition to the heavy metal load of lichens exposed along a busy road, based on the assumption that the accumulation of heavy metals occurs mostly as particles. We tested the hypothesis that lichens exposed inside a nylon cover with mesh size of 1 μm accumulate less heavy metals than lichens exposed without any cover. To this purpose, thalli of the lichen Evernia prunastri were transplanted for three months along a busy road of the urban area of Siena (Central Italy), with half of the samples exposed inside a nylon cover with a mesh size of 1 μm. The content of Al, As, Cd, Cr, Cu, Fe, Ni, Pb, Sb, and Zn was measured by ICP-MS before and after the exposure. The results showed that samples exposed inside the nylon cover accumulated a lower amount of most chemical elements and that Sb, along with Cd and Cu were the main traffic-related elements in the study area. Differences in element uptake were not caused by differences in sample vitality caused by the experimental procedure. Using a conversion factor it was possible to estimate element deposition rates for PM1 and PM > 1. Image 107 • Lichens exposed inside 1 μm mesh size nylon cover accumulate less heavy metals. • Cadmium, Cu and Sb are principal airborne traffic-related elements. • Lichens are a reliable tool to evaluate the chemical characteristics of PM1 fluxes. [ABSTRACT FROM AUTHOR]

• Car cabins of smokers may be contaminated by nicotine and heavy metals. • Lichens (Evernia prunastri) travelled for 2 months in smokers' and non-smokers' cars. • After travelling in smokers' cars, they accumulated nicotine and heavy metals. • Lichens in smokers' cars showed a 60% reduction of their vitality. In this work, two hypotheses have been tested: 1) that lichen transplants "travelling" in smokers' cars accumulate relevant amounts of nicotine and heavy metals from cigarette smoke, and 2) that such exposure affects their vitality. Lichen samples (Evernia prunastri) were exposed for two months inside the cabin of 10 volunteer's cars, equally distributed between smokers and non-smokers. Travelling in a smoker's car for two months increased the content of nicotine and heavy metals (Al, As, Cd, Cr, Cu, Ni, Pb and Sb) in the lichen. Exposed to Control (EC) ratios revealed an indoor uptake also for Cu and Sb in non-smoker's cars, caused by traffic pollution. A smoke factor, calculated as the ratio between values of smokers' and non-smokers' cars, indicated a 85.6-fold contribution for nicotine and contributions in the range 1.2 (Pb) to 2 (Ni) for heavy metals; in addition, after travelling in smokers' cars, lichens showed a remarkable (60%) reduction of their vitality, as indicated by the potential quantum yield of primary photochemistry. The study demonstrated that the effects of indoor pollution by cigarette smoke can be detected using lichen transplants. [ABSTRACT FROM AUTHOR]

The competitive behavior of divalent heavy metals (Cd, Cr, Pb, Zn) during cation uptake was investigated in the foliose lichen Xanthoria parietina . Lichen thalli were incubated with solutions containing 10 and 100 μM of CdCl 2, CuCl 2, and ZnCl 2 as well as 5 and 50 μM of Pb(NO 3 ) 2 , tested individually and in combination (Cd 2+ +Cu 2+ +Pb 2+ +Zn 2+ ). The analysis of molar concentrations suggests that a competition between cations for binding sites in X. parietina does exist. The decrease in net uptake between single and mixed solutions ranged between 14 and 29% at the lowest concentration and between 38 and 68% at the highest concentration. Furthermore, the uptake was proportionally lower for richer solutions. Each metal may behave differently when uptook: some (toxic elements) are preferentially stored at extracellular level (Cd, Pb), while others (micro-nutrients) are also present at intracellular level (Cu and Zn). The proportion between extracellular and total content changed for those elements accumulated also at intracellular level (Cu and Zn), while for Cd and Pb almost all the uptake occurred by passive mechanisms mainly at extracellular binding sites. The competition between metals for binding sites in the lichen surface entails that bioaccumulation data might result in an underestimation of some element levels measured in biomonitoring studies. [ABSTRACT FROM AUTHOR]

How long does it take a lichen to respond to changes (worsening or improvement) of atmospheric conditions is still discussed. We selected and removed lichen thalli ( Flavoparmelia caperata ) from sites subject to different intensities of pollution around a landfill in Central Italy and exposed them in a remote unpolluted area for 12 months. The content of elements of toxicological concern (As, Cd, Cr, Cu, Pb, Zn) and several physiological parameters in lichen thalli (chlorophyll a fluorescence emission, chlorophyll content and integrity, membrane lipid peroxidation, content of secondary metabolites and ergosterol content) were investigated before and after the recovery and hence compared with those of native (and clean) samples of the remote area. In an opposite trial, heavy metals content was investigated in samples taken from the remote area and exposed around the landfill. Values of the transplants were then compared with those of native samples at the landfill. From chemical point of view, the content of heavy metals decreased (by ca. 25%) in lichen thalli taken from the landfill and exposed in the remote area, however background values were never reached. On the other hand, lichen thalli taken from the remote area and exposed around the landfill accumulated up to ca. 80% of the content of in situ samples. The rate of accumulation was higher than the rate of element loss referred to the same temporal interval. The recovery of physiological parameters, especially those typical of the mycobiont or of the whole lichen symbiosis, was much faster than heavy metal detoxification, and after 12 months transplanted lichens already reflected the new environmental conditions at the remote site. [ABSTRACT FROM AUTHOR]

Lichens play an important role in the biogeochemical cycling of mercury (Hg) and are commonly used as indicators of Hg enrichment in remote and anthropogenically impacted environments. To assess their capacity for Hg uptake and accumulation, we determined the concentration of gaseous elemental mercury (GEM) in air and the concentration of total Hg (THg) in transplanted thalli of two lichen species. Lichen transplants and passive air samplers (PASs) were concurrently deployed, side by side, at 10 sites within an abandoned mining area, characterized by large gradients in atmospheric Hg contamination. Highly variable time-weighted GEM concentrations determined by the PASs, ranging from 17 to 4,200 ng/m3, were mirrored by generally high Hg concentrations in transplanted thalli of both Xanthoria parietina (174–8,800 ng/g) and Evernia prunastri (143–5,500 ng/g). Hg concentrations in the two species co-varied linearly indicating about 60% greater Hg accumulation in X. parietina than in E. prunastri. Whereas Hg uptake in the fruticose E. prunastri increased linearly with GEM, a power law equation with a fractional exponent described the uptake in the foliose X. parietina. Extrapolating the relationships observed here to higher GEM levels yielded concentrations in lichen that agree very well with those measured in an earlier fumigation experiment performed under laboratory-controlled conditions. The uptake model of X. parietina was further verified by correctly estimating GEM concentrations from the THg measured in autochthonous thalli collected from the urban area adjacent to the mine site. Passive sampling can effectively provide time-weighted data of suitable spatial resolution to quantitatively describe GEM assimilation by lichens. Therefore, the combined use of passive sampling and lichen transplants can contribute to a more comprehensive understanding of the role of lichens, and potentially also of other cryptogams, in the deposition of atmospheric Hg to terrestrial ecosystems. [Display omitted] • Transplanted lichens assimilate gaseous elemental Hg (GEM). • GEM uptake by the foliose X. parietina follows a power law equation. • The fruticose E. prunastri takes up Hg linearly with increasing GEM concentration. • Hg uptake rates of both lichen species transplants fit those of earlier experiments. • GEM concentrations can be predicted from autochthonous X. parietina data. [ABSTRACT FROM AUTHOR]

Epiphytic lichens have been used as indicators of environmental quality around a municipal solid waste landfill in C Italy. An integrated approach, using the diversity of epiphytic lichens, as well as element bioaccumulation and physiological parameters in the lichen Flavoparmelia caperata (L.) Hale was applied along a transect from the facility. The results highlighted the biological effects of air pollution around the landfill. The Index of Lichen Diversity (ILD) increased and the content of heavy metals (Cr, Cd, Cu, Fe, Ni and Zn) decreased with distance from the landfill. Clear stress signals were observed in lichens growing in front of the facility, i.e. discoloration, necrosis, membrane lipid peroxidation, lower ergosterol content, higher dehydrogenase activity. Decreased photosynthetic efficiency, altered chlorophyll integrity and production of secondary metabolites were also found. The results suggested that lichens can be profitably used as bioindicators of environmental quality around landfills. [ABSTRACT FROM AUTHOR]

A comprehensive biomonitoring programme should integrate several methods distributed along the biomonitoring chain, allowing to detect exposure, threads and impacts. In the case of a municipal solid waste incinerator (MSWI), biomonitoring of air pollution can contribute to source attribution, detection of ongoing processes and assessment of environmental effects. Three different methods were used to assess the biological effects of air pollution around a MSWI using lichens as biomonitors: (1) lichen diversity; (2) bioaccumulation of trace elements; and (3) physiological status (photosynthetic efficiency, cell membrane damage, viability). The first method takes into account the native lichen flora, while the other two were applied to thalli of the lichen Evernia prunastri transplanted for 6 months in the study area. Lichen diversity and physiological parameters reflected the effects of air pollution around the incinerator and the surrounding industrial area. High frequencies of non-nitrophilous species corresponded to sites with higher environmental quality, while high frequencies of nitrophilous species corresponded to sites with higher level of eutrophication. Transplanted samples showed increased cell membrane damage and reduced vitality respect to control samples. Bioaccumulation of trace elements pointed at the atmospheric origin of Hg depositions in the area. These results suggest that an integrated use of lichen-based methods along the biomonitoring chain can provide useful biological outputs for decision-makers to establish correct sustainable waste management policies. [ABSTRACT FROM AUTHOR]

Highlights: [•] Dust contamination from quarrying affected the lichen diversity within 350m. [•] At the quarry basi-nitrophilous species increased and acidophilous species decreased. [•] Basiphilous species had a higher cover on the side facing the quarry. [•] Ca, Ti, Fe, V, Al, Ni were significantly higher at the quarries and the cement mill. [•] The content of Ca decreased with increasing distance from the cement mill. [Copyright &y& Elsevier]

Abstract: Objective: To assess the additional diagnostic value of contrast-enhanced ultrasound (CEUS) in the characterization of indeterminate solid hepatic lesions identified on non-diagnostic contrast-enhanced computed tomography (CT). Methods: Fifty-five solid hepatic lesions (1–4cm in diameter) in 46 non-cirrhotic patients (26 female, 20 male; age±SD, 55±10 years) underwent CEUS after being detected on contrast-enhanced CT which was considered as non-diagnostic after on-site analysis. Two blinded independent readers assessed CT and CEUS scans and were asked to classify retrospectively each lesion as a malignant or benign based on reference diagnostic criteria for the different hepatic lesion histotypes. Diagnostic accuracy and confidence (area – A z – under ROC curve) were assessed by using gadobenate dimeglumine-enhanced magnetic resonance (MR) imaging (n =30 lesions), histology (n =7 lesions), or US follow-up (n =18 lesions) as the reference standards. Results: Final diagnoses included 29 hemangiomas, 3 focal nodular hyperplasias, 1 hepatocellular adenoma, and 22 metastases. The additional review of CEUS after CT images improved significantly (P <.05) the diagnostic accuracy (before vs after CEUS review=49% [20/55] vs 89% [49/55] – reader 1 and 43% [24/55] vs 92% [51/55] – reader 2) and confidence (A z , 95% Confidence Intervals before vs after CEUS review=.773 [.652–.895] vs .997 [.987–1] – reader 1 and .831 [.724–.938] vs .998 [.992–1] – reader 2). Conclusions: CEUS improved the characterization of indeterminate solid hepatic lesions identified on non-diagnostic contrast-enhanced CT by identifying some specific contrast enhancement patterns. [Copyright &y& Elsevier]

Abstract: We analysed the value of contrast-enhanced ultrasound to differentiate inflammatory from fibrotic ileal strictures in patients with Crohn''s disease (CD). Twenty-eight patients (17 male and 11 female; mean age ± SD, 48.5 ± 17.17 years) with a biopsy-proven diagnosis of CD were included. In each patient, the terminal ileal loop was scanned by a convex-array probe (2–5 MHz) before and after sulphur hexafluoride-filled microbubble injection. The digital cine-clip registered after microbubble injection during the first-pass dynamic enhancement was quantified in gray-scale levels by a dedicated software through manually drawn regions-of-interest (ROIs) encompassing the anterior bowel wall. Time-intensity curves from patients with inflammatory and fibrotic ileal strictures, fitted according to the theoretical gamma variate curve, were compared. Inflammatory vs. fibrotic ileal strictures differed in the percentage of maximal enhancement (45.86 ± 5.32 vs. 37.33 ± 16.24%; p < 0.05) and area under the enhancement curve (1168.25 ± 437.65 vs. 570.47 ± 323.08; p < 0.05), whereas the difference in time to peak enhancement was found not significant (9.25 ± 4.21 vs. 12.01 ± 7.34 s; p > 0.05). The quantitative analysis of small bowel wall contrast enhancement after microbubble contrast agent injection may differentiate inflammatory from fibrotic ileal strictures in patients with CD. [Copyright &y& Elsevier]

Rationale and Objectives: To retrospectively assess the value of spectral presaturation by inversion-recovery (SPIR) magnetic resonance (MR) imaging sequence after gadolinium injection to differentiate fibrotic scar tissue and tumoral infiltration within the mesorectal fat in patients with rectal carcinoma undergoing MR restaging after neoadjuvant chemo- and radiation therapy (CRT).Materials and Methods: Forty-three consecutive patients (mean age, 65.8 years; range, 46-85 years; male:female, 29:14) with locally advanced rectal carcinoma underwent CRT followed by surgery. MR imaging was performed before and after completion of CRT by using T2-weighted turbo spin-echo and T1-weighted SPIR sequences before and after gadolinium injection, and MR images were assessed by two radiologists in consensus. Logistic regression was conducted to test the significance of the MR image findings with histology.Results: After CRT the disease was either limited to the rectal wall (n = 18 patients) or presented perirectal infiltration (n = 25) on histology. In 21 patients, mesorectal enhancing strands were observed. Reticular-shaped enhancing strands reaching the mesorectal fascia presented the highest correlation with tumor infiltration of the mesorectal fat (OR 130.33, 95% CI: 4.1-4220.29; logistic regression), whereas linear-shaped enhancing strands either reaching or not reaching the mesorectal fascia (OR 0.25 or 0.1, 95% CI: 0.024-2.6 or 0.01-1.07) revealed the lowest correlation.Conclusions: Reticular-shaped enhancing strands on SPIR MR imaging after gadolinium injection are associated with tumor infiltration of the mesorectal fat. [ABSTRACT FROM AUTHOR]

This study investigated if atmospheric ammonia (NH3) pollution around a sheep farm influences the photosynthetic performance of the lichens Evernia prunastri and Pseudevernia furfuracea. Thalli of both species were transplanted for up to 30 days in a semi-arid region (Crete, Greece), at sites with concentrations of atmospheric ammonia of ca. 60 μg/m3 (at a sheep farm), ca. 15 μg/m3 (60 m from the sheep farm) and ca. 2 μg/m3 (a remote area 5 km away). Lichen photosynthesis was analysed by the chlorophyll a fluorescence emission to identify targets of ammonia pollution. The results indicated that the photosystem II of the two lichens exposed to NH3 is susceptible to this pollutant in the gas-phase. The parameter PIABS, a global index of photosynthetic performance that combines in a single expression the three functional steps of the photosynthetic activity (light absorption, excitation energy trapping, and conversion of excitation energy to electron transport) was much more sensitive to NH3 than the F V/F M ratio, one of the most commonly used stress indicators. [Copyright &y& Elsevier]

Abstract: The suitability of a set of ecophysiological parameters, to be used as early warning indicator to detect signs of a worsening environment around geothermal power plants, was tested by comparison with the diversity of epiphytic lichens, a well-established indicator of geothermal air pollution. Samples of the lichen Evernia prunastri were transplanted around a geothermal power plant at Larderello (Tuscany, Italy) and at a control site, and integrity of cell membranes, concentration of chlorophyll a, b and carotenoids, chlorophyll integrity and variations in pH of thalli were measured. The results showed that cell membrane damage, expressed by changes in electrical conductivity, could be used to detect early (exposure periods as short as 1 month) deleterious effects of geothermal air pollution. [Copyright &y& Elsevier]

• Air pollution influences the success of lichen translocation for conservation purposes. • The translocation of Lobaria pulmonaria is effective only in unpolluted environments. • Higher contents of heavy metals in translocated thalli reflect their lower survival. • Current air quality in Central Europe limits recolonization by sensitive lichens. Species translocation can be considered as a primary conservation strategy with reference to in situ conservation. In the case of lichens, translocations often risk to fail due stress factors associated with unsuitable receptor sites. Considering the bioecological characteristics of lichens, air pollution is among the most limiting stress factors. In this study, the forest macrolichen Lobaria pulmonaria was used as a model to test the hypothesis that the translocation of sensitive lichens is effective only in unpolluted environments. At purpose, 500 fragments or whole thalli were translocated in selected beech forests of Central Europe (the Western Carpathians, Slovakia) where the species disappeared in the past and in oak forests of Southern Europe (Tuscany, Central Italy) where native populations are present. Prior to the translocation (May 2016) and after one year, morphological and ultrastructural features, trace elements as well as chlorophyll a fluorescence emission were analysed. Four years later, the effectiveness of lichen translocation was further evaluated as presence of the transplants and of newly formed individuals. After one year, the translocation ensured an effective survival of the thalli in remote oak and beech forests characterized by a negligible or low contamination by heavy metals. The transplants were considered successful and developed new lobules and rhizines, attaching by themselves to the bark of the host trees, looking overall healthy, without evident signs of alteration also at ultrastructural level. Moreover, in a few cases newly formed individuals were observed after four years. On the other hand, the results highlighted the link between the unsuccess of the translocation and air pollution in other areas of the Western Carpathians and suggested that current air quality still limits the possibility of recolonization in areas where the model species disappeared. [ABSTRACT FROM AUTHOR]

Biocidal products are widely used to devitalize lichen thalli on monumental surfaces before their mechanical removal, but there is still lack of information about the persistence of the toxic effects over time. This issue is of paramount importance since it can greatly influence the process of lichen recolonization. The aim of this study was checking for physiological recovery or residual vitality of lichens after exposure to two commercial biocidal products, Biotin T or Preventol RI80. Samples of the foliose lichen Xanthoria parietina were treated with solutions containing the two biocides at the highest concentration suggested by the producer (3% and 2% respectively). Selected physiological parameters were investigated as indicators of sample vitality: photosynthetic parameters (F V /F M and PI ABS ), the content of chlorophyll a , chlorophyll b , beta-carotene, ergosterol and soluble proteins, after 24 and 72 hours and, to check for recovery, after 20 and 90 days. Both biocidal treatments induced severe physiological alterations, causing impairment to both the lichen photobiont and mycobiont, with Preventol showing a faster effect. The substantial loss of vitality following treatments with Biotin T and Preventol persisted over time, and no physiological recovery was found after 90 days. [ABSTRACT FROM AUTHOR]

This study compared bioaccumulation as well as physiological (content of ergosterol as marker of fungal vitality and photosynthetic efficiency as marker of algal vitality) and ultrastructural effects of glyphosate in the lichen Xanthoria parietina , with the herbicide being provided either by soaking or spraying of the samples. The results showed that bioaccumulation of glyphosate is fast and proportional to the dose supplied, and is independent on the way it is supplied. Toxic effects resulting from glyphosate uptake by both soaking and spraying were evident at physiological and ultrastructural level, both in the algal and fungal partner, with negative effects being generally dose- and time-dependent. Since our results showed that the concentration of glyphosate bioaccumulated in X. parietina remains stable (at least up to 90 days), a perspective is open for using lichens in biomonitoring of atmospheric pollution by glyphosate as a side effect of the application of this herbicide. [ABSTRACT FROM AUTHOR]

Objective: To assess spectral presaturation inversion-recovery MRI sequence with gadolinium to identify predictors of mesorectal fascia (MRF) invasion in patients with locally advanced rectal carcinoma after neoadjuvant therapy. Materials and methods: Sixty-five patients underwent neoadjuvant concomitant radiation and chemotherapy and surgery. Magnetic resonance images were assessed by two radiologists. Results: Linear (odds ratio, 95% confidence intervals: 19.33, 1.98-188.6) and reticular strands (odds ratio, 95% confidence intervals: 9.75, 1.45-67.77) reaching the MRF are predictors of MRF invasion. Conclusion: Linear or reticular mesorectal strands reaching the MRF detected at contrast-enhanced MRI represent a predictor of MRF invasion. [ABSTRACT FROM AUTHOR]

Leaf nutrient composition and stoichiometry reflect complex interactions of the plant with its environment and are useful traits to explore ecological processes and relationships. In the present study, the foliar elemental compositions of two common Mediterranean woody species, the evergreen broad-leaved Quercus ilex and the coniferous Pinus pinaster growing in an area of Central Italy known for geochemical and geothermal anomalies, were investigated. To assess the site-specific and age-dependent pattern of foliar composition and stoichiometry, macronutrients (C, N, P, K, Mg, S) and trace elements (Al, As, Ba, Cd, Cr, Cu, Fe, Hg, Ni, Pb, Sb, V, Zn) were determined in leaves and needles of three different ages (6-, 12- and 24-month-old) collected from metalliferous (geothermal, mining) and rural areas. Leaves of Q. ilex showed comparatively high concentrations of micronutrients (i.e., Cu, Fe and Zn), while needles of P. pinaster accumulated significantly high concentrations of potentially toxic elements (i.e., As, Pb and S). No significant trend was found in elemental concentrations in relation to the age of leaves and needles. Multi-element stoichiometry of P. pinaster was driven by the geochemical heterogeneity of the sites, suggesting plastic adaptation at the sites with the most selective edaphoclimatic conditions (i.e., patches with nutrient poor and metalliferous soils). On the other hand, the content of both nutrients and potentially toxic elements in Q. ilex leaves varied little across the study area, reflecting stoichiometric stability; this is consistent with the ecophysiological features of Q. ilex as a late-successional species with a dominant role in the ecosystems of the Mediterranean area. Our findings demonstrate the value of foliar stoichiometric traits for understanding plant adaptation in a heterogeneous environment and also the consequences of biotic interactions during succession. [Display omitted] • Needles of P. pinaster accumulate potentially toxic elements, such as As, Pb and S. • Nutritional plasticity distinguishes P. pinaster colonizing mining and geothermal sites. • Invariant nutritional status (homeostasis) characterizes the late-successional Q. ilex. • Multi-elemental foliar composition reveals pine-ecosystem interactions. [ABSTRACT FROM AUTHOR]

Abstract: This study aimed at investigating the cellular distribution of Hg in the lichens Cladonia arbuscula subsp. mitis and Peltigera rufescens treated with Hg2+ and at testing if Hg treatment affects selected physiological parameters. In both species, increasing Hg accumulation under increasing Hg supply in the treatment solutions was found. P. rufescens showed a higher intracellular accumulation. Photosynthetic parameters were negatively affected in both species, as indicated by the decrease in photosynthetic pigments content, photosynthetic efficiency and chlorophyll integrity. Cell membranes of both species endured damage as indicated by the increase in the concentration of products of lipid peroxidation and decrease in ergosterol content. Nevertheless, differences between the two species were found, suggesting a differential sensitivity to Hg. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this study was to test in a short term laboratory experiment the accumulation and physiological effects of As in the epiphytic lichen Xanthoria parietina. Arsenic content in treated samples increased progressively with increasing concentration in treatment solutions. Treatment of X. parietina thalli with 0.1, 1, 10ppm As solutions caused significant decrease of viability, measured as intensity of respiratory activity, and damages to cell membranes, assessed by increase of electric conductivity of rinsing water and lipid peroxidation products. Soluble proteins content decreased and H2O2 content increased already at the lowest As concentration tested (0.01ppm). Photosynthetic efficiency, measured in terms of FV /FM ratio, decreased significantly only at the highest As concentration (10ppm). It was concluded that As exposure causes physiological stress both on the mycobiont and the photobiont and that cell membrane damage, expressed in terms of electric conductivity of rinsing water, is the parameter most affected by As treatment. [ABSTRACT FROM AUTHOR]

Abstract: The results of a study aimed at investigating the effects of boron excess on a set of ecophysiological parameters in the lichen Xanthoria parietina, to set up a monitoring system to trace early biological effects of boron pollution in geothermal areas, are reported. To this purpose, lichen thalli have been incubated for 24h in solutions at boron concentrations of 0.1, 1, 10 and 100ppm, which were within the range in bulk deposition and geothermal fluids. The results showed a general trend of decreasing sample viability and increasing cell membrane damage and membrane lipid peroxidation under increasing boron concentrations, while photosynthetic efficiency, chlorophyll degradation and the contents of H2O2 and water-soluble proteins were not affected. It was argued that the fungal partner, that represents the large majority of the lichen biomass, is more sensitive to boron excess than the algal partner. [Copyright &y& Elsevier]

The fruticose epiphytic lichen Seirophora villosa , strictly associated with Juniperus shrublands in the Mediterranean basin, was used to investigate the role of hairiness on a lichen thallus, as a characteristic morphological trait. We evaluated the effect of hair removal on the physiological parameters of a set of samples, during desiccation and on exposure to different salt concentrations. Hairy thalli were less affected by salt, suggesting that during dehydration, the presence of hair protects the thallus from light irradiance, oxidative stresses and the lipid peroxidation generated by free radicals, and could offer passive, but selective, water control. Our results showed that hair could not only increase thallus surface and promote water absorption when availability is low, but could also repel the salt dissolved in water by activating a passive resistance mechanism, by preventing salt entering. Image 1 • Morphological and physiological traits of lichens are linked to specific functions. • Seirophora villosa was used as a model species to investigate the role of hairiness. • Hair protects the thallus from oxidative stresses and the lipid peroxidation. • Hair acts as a shield to counteract different sources of stress. [ABSTRACT FROM AUTHOR]

Control of lichens on stone cultural heritage is mostly achieved by a combination of mechanical removal with biocide applications. However, there is a lack of scientific evidence on the efficacy of different biocides on different species, and on the consistency of biocide effects on heritage sites in different environmental conditions. This results in some uncertainty when conservation interventions to control lichens are routinely defined on the basis of restoration tradition or empirical evaluation, without experimental measures of how lichens respond. In this work, we quantitatively evaluated (a) the efficacy of five commercially-available biocides, applied using a brush or with a cellulose poultice, against two species ( Protoparmeliopsis muralis , Verrucaria nigrescens ), and (b) whether the effects on the two species were consistent, per treatment, across three Italian heritage sites. Lichen vitality was quantified through analyses of chlorophyll a fluorescence (Chl a F) and ergosterol content. The results indicated that all the tested biocides, and their organic solvents, affected the vitality of both the species. However, most of treatments displayed different efficacy on each species, across the different sites and between brush and poultice applications. Accordingly, when a conservation intervention to control lichen growth is planned, biocide treatments need both species- and site-specific calibrations and lichen vitality should be properly ascertained in situ by monitoring Chl a F parameters (F V /F M and F 0 ) twenty days after trial biocide applications. [ABSTRACT FROM AUTHOR]

This work analyzed the influence of different application protocols on the efficacy of two biocides against the foliose lichen Xanthoparmelia tinctina on the sandstones of the Roman Archaeological site of Luni (Italy). The hypotheses that (a) biocide application tools (brush vs. poultice), (b) pre-treatment hydration, and (c) post-treatment washing may affect devitalization success were verified by monitoring chlorophyll a fluorescence of thalli, both in situ and in laboratory conditions. The hypothesis that (d) stone substrate may act as reservoir for later biocide release under repeated cycles of wetting and drying was also assayed. Analyses confirmed the importance of the application tool, with cellulose poultice being more effective than brush. Hydration influenced the biocide absorption by thalli. Moreover it modulated the metabolic activity and susceptibility to the available toxic compound, hindering lichens from entering a dormant state to tolerate stress. Depending on the preparation solvent (water vs. white spirit), the biocide application benefited from pre-treatment hydration and/or a post-treatment washing. Lastly, we showed that different sandstones variously adsorb the biocides and potentially contribute as a reservoir for their long-term release at low concentrations during successive hydration events. Image 1 • The protocol to apply biocides on lichens affects the devitalization effects. • Cellulose poultice application of biocides is more effective than that by brush. • Pre-hydration and/or post-washing of thalli regulate biocide effectiveness. • The stone substrate acts as a reservoir for long-term release of biocide. • Effective application protocols can limit useless chemical release to the environment. [ABSTRACT FROM AUTHOR]