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[en] To develop an internationally standardized protocol for the moss bag technique application, the research team participating in the FP7 European project “MOSSclone” focused on the optimization of the moss bags exposure in terms of bag characteristics (shape of the bags, mesh size, weight/surface ratio), duration and height of exposure by comparing traditional moss bags to a new concept bag, “Mossphere”. In particular, the effects of each variable on the metal uptake from the air were evaluated by a systematic experimental design carried out in urban, industrial, agricultural and background areas of three European countries with oceanic, Mediterranean and continental climate. The results evidenced that the shape, the mesh size of the bags and the exposure height (in the tested ranges), did not significantly influence the uptake capacity of the transplanted moss. The aspects more affecting the element uptake were represented by the density of the moss inside the bags and the relative ratio between its weight and the surface area of the bag. We found that, the lower the density, the higher the uptake recorded. Moreover, three weeks of exposure were not enough to have a consistent uptake signal in all the environments tested, thus we suggest an exposure period not shorter than 6 weeks, which is appropriate in most situations. The above results were confirmed in all the countries and scenarios tested. The adoption of a shared exposure protocol by the research community is strongly recommended since it is a key aspect to make biomonitoring surveys directly comparable, also in view of its recognition as a monitoring method by the EU legislation. - Highlights: • Variables affecting moss bag uptake were tested by systematic experimental design. • Variables investigated were: shape, mesh size, density, height and exposure time. • A new concept bag “Mossphere” was developed. • Uptake effectiveness was evaluated in four scenarios of three EU countries. • The variables most affecting uptake are moss density and exposure time. - Variables significantly affecting moss bag uptake are exposure time and moss weight/bag surface ratio.
[en] Mosses, characterised by a slow growth, are able to efficiently accumulate different radionuclides from the environment to a much higher degree than other vegetation. Consequently, mosses are sensitive bioindicators of radioactive contamination in various ecosystems. Radioactivity released into air after the accident in the Fukushima Dai-ichi nuclear power plant has become part of atmospheric processes and the transport of matter in the biosphere. During the last five years, mosses were sampled at three selected locations: in the courtyard of the Institute for medical research in Zagreb (IMI), at an active gas well in Podravina (Molve) and near orchards and vineyards in Klostar Ivanic. Moss samples were before analysis dried in an oven and after that usually ashed. All the samples were analysed by means of gamma-ray spectrometry using HP GMX and/or Ge(Li) detectors connected with a data acquisition system. The obtained results show the following relations between 137Cs and 134Cs activity concentrations on selected locations: 137Cs: AKlostar < AIMI < AMolve 134Cs: AMolve < AKlostar < AIMI It is shown that the differences in 137Cs activity concentrations are statistically significant. There are at least two mechanisms present in mosses, one based on the transfer of metals (caesium) with dust uplifted from soil and the other one based on the diffusion in aqueous solution wetting a moss. We assume that the differences in the 137Cs activity concentrations are caused by the mosses growing at different locations with different fallout characteristics (wet and dry deposition). The 134Cs activity concentration is small everywhere, near the values of the detection limits. The study was conducted in the Radiation Protection Unit of the Institute for Medical Research and Occupational Health in Zagreb, as a part of an extensive monitoring program of the Croatian environment. (author).
[en] Nitrogen deposition at current ambient levels in Wales is detrimental to shoot growth of Racomitrium lanuginosum. - Racomitrium lanuginosum shoot growth was studied under the combined effects of N deposition (0, 20, 40 and 60 kg N ha-1 year-1), competition with Festuca ovina, and a drought pre-treatment. Moss regeneration from shoot fragments was also investigated. Growth was initially stimulated at the 60 kg N level. However, after 6 months, growth was lower in all N treatments than in the 0 kg N control. Reductions in shoot growth first became apparent in the pre-desiccated moss, while moss shoots grew longer when surrounded by a F. ovina canopy. Optimum regeneration occurred at 20-40 kg N on bare soil, and at 0-20 kg N under a F. ovina canopy. These results suggest that current N deposition in upland Wales is already detrimental to growth of this species, and to regeneration under certain conditions. This species may be affected under predicted climatic scenarios of increased summer drought in Britain
[en] Some basic facts about the use of mosses as biomonitors of atmospheric trace element deposition are reviewed, and advantages and limitations of this approach are discussed, largely on the basis of experience from regular use of this technique in Norway over the last 20 years. Topics discussed include different versions of the moss technique, mechanisms and efficiencies of trace element uptake, conversion of concentrations in moss to bulk deposition rates, and contribution from sources other than air pollution to the elemental composition of different elements. Suggestions are presented for further work in order to extend the use of mosses as biomonitors. (author)
[en] Tree hollows often harbor animals and microorganisms, thereby storing nutritive resources derived from their biological activities. The outflows from tree hollows can create unique microenvironments, which may affect communities of epiphytic organisms on trunk surfaces below the hollows. In this study, we tested whether the species richness and composition of epiphytic bryophytes (liverworts and mosses) and lichens differ above and below tree hollows of Aria japonica and Cercidiphyllum japonicum in a Japanese temperate forest. The species richness of epiphytic bryophytes and lichens did not differ above and below hollows; however, the species composition of bryophytes differed significantly above and below hollows. Indicator species analyses showed that the moss species Anomodon tristis and the liverwort species Porella vernicosa were significantly more common below than above hollows, while the liverwort species Radula japonica and four lichen species, including Leptogium cyanescens, occurred more frequently above than below hollows. Our results highlight that tree hollows can produce unique microenvironments on trunk surfaces that potentially contribute to the maintenance of epiphytic diversity on a local scale.
[en] Biomonitoring with mosses is a common method widely used to assess the spatial and temporal trends of atmospheric deposition in Europe since its introduction in the 1970s. Based on previous investigations, certain moss species provide the most accurate reflection of atmospheric deposition. However, sampling of just one species across large areas can pose a challenge, therefore the ability to use multiple moss species interchangeably is integral to an effective moss biomonitoring survey. In this study, biomonitoring abilities of two common species (Hylocomium splendens [Hs] and Pleurozium schreberi [Ps]) were compared to a potential new biomonitoring species endemic to North America (Isothecium stoloniferum [Is]). Thirteen metal concentrations were analyzed (Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Cd, and Pb) in moss tissue from 20 sites with co-located species (Ps/Hs, Is/Hs) Five metals (Al, V, Fe, Ni, and Pb) showed significant and strong correlations (Spearman correlation, r ≥ 0.7 α = 0.05) for all three species, reflecting the established deposition gradient in the region. Furthermore, there was no significant difference in observations (and moderate correlation) for Cr, which suggests that all species exhibited similar uptake abilities for these six metals (Al, V, Cr, Fe, Ni, and Pb). Four metals (Co, As, Se, and Cd) exhibited concentrations below detection at a number of sites, which may have influenced the assessment of interspecies relationships. It is recommended that interspecies calibration be carried out under all surveys that employ multiple moss species.
[en] The structural simplicity of the bryophytes exposed them easily to water stress, forcing them to have physiological and biochemical mechanisms that enable them to survive. This study evaluated the variation of total soluble sugars and reducing sugars in relation to relative water content, in Pleurozium schreberi when faced with low water content in the Paramo de Chingaza (Colombia) and under simulated conditions of water deficit in the laboratory. we found that total sugars increase when the plant is dehydrated and returned to their normal content when re-hydrated moss, this could be interpreted as a possible mechanism of osmotic adjustment and osmoprotection of the cell content and cellular structure. Reducing sugars showed no significant variation, showing that monosaccharides do not have a protective role during dehydration.
[en] The Red forest lot is plased in the forestry, joining to RNW territory on the west and the south-west side (375 hectare). The forest massif at the accident moment received absorbed dose 8000-10000, rad that led to a complete ruin all pine truss on the territory. As far as lost truss absorbed a considerable amount of the radioactive elements excretion and become to a strong irradiation source, an unbroken felling and ground disposal of the wood are performed. The all felled area wal filled wit a river sand (30-50 cm). The whole lot sowed with the rye and perennial grasses. At the present time on the territory a grassy vegetation forms the foundation of the vegetable cover. A wide spreading of mosses is the typical feature of the territory. The gamma-spectral composition is stadied of incorporated isotopes in dry vegetable biomass from the territory (the mass various grasses species). 9 refs.; 2 figs
[en] In this study we examined 6080 data gathered by our research group during more than 20 years of research on the moss biomonitoring technique, in order to quantify the variability generated by different aspects of the protocol and to calculate the overall measurement uncertainty associated with the technique. The median variance of the concentrations of different pollutants measured in moss tissues attributed to the different methodological aspects was high, reaching values of 2851 (ng·g−1)2 for Cd (sample treatment), 35.1 (μg·g−1)2 for Cu (sample treatment), 861.7 (ng·g−1)2 and for Hg (material selection). These variances correspond to standard deviations that constitute 67, 126 and 59% the regional background levels of these elements in the study region. The overall measurement uncertainty associated with the worst experimental protocol (5 subsamples, refrigerated, washed, 5 × 5 m size of the sampling area and once a year sampling) was between 2 and 6 times higher than that associated with the optimal protocol (30 subsamples, dried, unwashed, 20 × 20 m size of the sampling area and once a week sampling), and between 1.5 and 7 times higher than that associated with the standardized protocol (30 subsamples and once a year sampling). The overall measurement uncertainty associated with the standardized protocol could generate variations of between 14 and 47% in the regional background levels of Cd, Cu, Hg, Pb and Zn in the study area and much higher levels of variation in polluted sampling sites. We demonstrated that although the overall measurement uncertainty of the technique is still high, it can be reduced by using already well defined aspects of the protocol. Further standardization of the protocol together with application of the information on the overall measurement uncertainty would improve the reliability and comparability of the results of different biomonitoring studies, thus extending use of the technique beyond the context of scientific research. - Highlights: • The overall measurement uncertainty associated with the moss technique was calculated. • Uncertainty decreased when using the worst vs. standardized vs. optimal experimental set up. • Although the overall uncertainty of the technique is still high, it can be reduced. • Standardization of the protocol improves the reliability and comparability of the results. - Measurement uncertainty associated to the results of the moss technique is significantly reduced when applying a standardized protocol.
[en] In 2005/6, nearly 3000 moss samples from (semi-)natural location across 16 European countries were collected for nitrogen analysis. The lowest total nitrogen concentrations in mosses (<0.8%) were observed in northern Finland and northern UK. The highest concentrations (≥1.6%) were found in parts of Belgium, France, Germany, Slovakia, Slovenia and Bulgaria. The asymptotic relationship between the nitrogen concentrations in mosses and EMEP modelled nitrogen deposition (averaged per 50 km x 50 km grid) across Europe showed less scatter when there were at least five moss sampling sites per grid. Factors potentially contributing to the scatter are discussed. In Switzerland, a strong (r2 = 0.91) linear relationship was found between the total nitrogen concentration in mosses and measured site-specific bulk nitrogen deposition rates. The total nitrogen concentrations in mosses complement deposition measurements, helping to identify areas in Europe at risk from high nitrogen deposition at a high spatial resolution. - Highlights: → Nitrogen concentrations in mosses were determined at ca. 3000 sites across Europe. → Moss concentrations were compared with EMEP modelled nitrogen deposition. → The asymptotic relationship for Europe showed saturation at ca. 15 kg N ha-1 y-1. → Linear relationships were found with measured nitrogen deposition in some countries. → Moss concentrations complement deposition measurements at high spatial resolution. - Mosses as biomonitors of atmospheric nitrogen deposition in Europe.