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The use of transplanted moss (Pleurozium schreberi) in active biomonitoring of traffic-related emissions of Pd, Pt, and Rh was studied. Moss mats were transplanted to three locations along highway E75 (in Oulu, Finland) at three different distances from the highway. Five samples were collected from a background site after the same exposure period. Mass fractions of Pd, Pt, and Rh as well as mass fractions of 18 other elements were determined in these samples. The results indicated that P. schreberi is well suited for active biomonitoring of Pd, Pt, and Rh. Mass fractions above the background values were observed in the samples exposed to traffic-related emissions. When the results were compared with those of the other elements, high correlations of Pd, Pt, and Rh with commonly traffic-related elements (e.g., Cu, Ni, Sb, Zn, etc.) were found. It was also found that the amounts of Pd, Pt, and Rh in moss samples decreased when the distance to the highway increased. This trend gives evidence for the suitability of P. schreberi for active biomonitoring of Pd, Pt, and Rh. Furthermore, it can be concluded that the mass fractions determined in this study provide valuable evidence about the current state of Pd, Pt, and Rh emissions in Oulu, Finland.

Mosses take up nitrogen (N) mainly from precipitation through their surfaces, which makes them competent bioindicators of N deposition. We found positive relationships between the total N concentration (mossN%) of common terrestrial moss species (feather mosses Pleurozium schreberi and Hylocomium splendens, and a group of Dicranum species) and different forms of N deposition in 11-16 coniferous forests with low N deposition load in Finland. The mosses were collected either inside (Dicranum group) or both inside and outside (feather mosses) the forests. Deposition was monitored in situ as bulk deposition (BD) and stand throughfall (TF) and detected for ammonium (NH4+-N), nitrate (NO3--N), dissolved organic N (DON), and total N (N-tot, kg ha(-1)yr(-1)). N-tot deposition was lower in TF than BD indicating that tree canopies absorbed N from deposition in N limited boreal stands. However, mossN % was higher inside than outside the forests. In regression equations, inorganic N in BD predicted best the mossN% in openings, while DON in TF explained most variation of mossN% in forests. An asymptotic form of mossN% vs. TF N-tot curves in forests and free NH4+-N accumulation in tissues in the southern plots suggested mosses were near the N saturation state already at the N-tot deposition level of 3-5 kg ha(-1) yr(-1). N leachate from ground litterfall apparently also contributed the N supply of mosses. Our study yielded new information on the sensitivity of boreal mosses to low N deposition and their response to different N forms in canopy TF entering moss layer. The equations predicting the N-tot deposition with mossN% showed a good fit both in forest sites and openings, especially in case of P. schreberi. However, the open site mossN% is a preferable predictor of N deposition in monitoring studies to minimize the effect of tree canopies and N leachate from litterfall on the estimates. (C) 2020 Elsevier Ltd. All rights reserved.

In recent decades, naturally growing mosses have been used successfully as biomonitors of atmospheric deposition of heavy metals and nitrogen. Since 1990, the European moss survey has been repeated at five-yearly intervals. In 2010, the lowest concentrations of metals and nitrogen in mosses were generally found in northern Europe, whereas the highest concentrations were observed in (south-)eastern Europe for metals and the central belt for nitrogen. Averaged across Europe, since 1990, the median concentration in mosses has declined the most for lead (77%), followed by vanadium (55%), cadmium (51%), chromium (43%), zinc (34%), nickel (33%), iron (27%), arsenic (21%, since 1995), mercury (14%, since 1995) and copper (11%). Between 2005 and 2010, the decline ranged from 6% for copper to 36% for lead ; for nitrogen the decline was 5%. Despite the Europe-wide decline, no changes or increases have been observed between 2005 and 2010 in some (regions of) countries.

The use of Pt and Rh as active components in automobile catalytic converters has led to increasing concentrations of these elements in several natural matrices. Because of this, the suitability of the use of a terrestrial moss (Pleurozium schreberi) for the passive biomonitoring of traffic-related Pt and Rh deposition was studied. The moss samples collected from Finland in and around areas with heavy traffic had increased Pt and Rh concentrations, with maximum values of 12.2 and 4.5 ng g(-1), respectively. In addition, the concentrations of commonly used catalytic converter additives (Al, Ce, La, Y, and Zr) and some elements related to traffic or mineral dust (Cd, Cu, Fe, Hf, Pb, and Zn) were also measured to obtain more information about the sources of Pt and Rh. Multivariate principal component analysis and cluster analysis were applied for identification of the emission sources of the elements. The results indicated a common traffic-related source of Pt and Rh. However, the results also showed that Pt and Rh concentrations in mosses are increased only in areas located close to traffic lanes.

For analysing element input into ecosystems and associated risks due to atmospheric deposition, element concentrations in moss provide complementary and time-integrated data at high spatial resolution every 5 years since 1990. The paper reviews (1) minimum sample sizes needed for reliable, statistical estimation of mean values at four different spatial scales (European and national level as well as landscape-specific level covering Europe and single countries); (2) trends of heavy metal (HM) and nitrogen (N) concentrations in moss in Europe (19902010); (3) correlations between concentrations of HM in moss and soil specimens collected across Norway (19902010); and (4) canopy drip-induced site-specific variation of N concentration in moss sampled in seven European countries (19902013). While the minimum sample sizes on the European and national level were achieved without exception, for some ecological land classes and elements, the coverage with sampling sites should be improved. The decline in emission and subsequent atmospheric deposition of HM across Europe has resulted in decreasing HM concentrations in moss between 1990 and 2010. In contrast, hardly any changes were observed for N in moss between 2005, when N was included into the survey for the first time, and 2010. In Norway, both, the moss and the soil survey data sets, were correlated, indicating a decrease of HM concentrations in moss and soil. At the site level, the average N deposition inside of forests was almost three times higher than the average N deposition outside of forests. © 2016, Springer-Verlag Berlin Heidelberg.

To assess the relationship between nitrogen concentrations in mosses and wet bulk nitrogen deposition or concentrations in precipitation, moss tissue and deposition were sampled within a distance of 1 km of each other in seven European countries. Relationships for various forms of nitrogen appeared to be asymptotic, with data for different countries being positioned at different locations along the asymptotic relationship and saturation occurring at a wet bulk nitrogen deposition of ca. 20 kg N ha(-1) yr(-1). The asymptotic behaviour was more pronounced for ammonium-N than nitrate-N, with high ammonium deposition at German sites being most influential in providing evidence of the asymptotic behaviour. Within countries, relationships were only significant for Finland and Switzerland and were more or less linear. The results confirm previous relationships described for modelled total deposition. Nitrogen concentration in mosses can be applied to identify areas at risk of high nitrogen deposition at European scale.

A systematic mapping of thirteen epiphytic lichen species on conifers was carried out in Finland at the first time in 1985–1986 and the second time in 1995. The aim of mapping work was to describe the regional distribution of the most common epiphytic lichens and to assess air quality based on the abundance of epiphytic lichens. All lichen species demonstrated increases in their abundance between the years 1985 and 1995. Scoliciosphorum chlorococcum , a species tolerant to air pollution, increased most in parts of the southern Finland where the nitrogen levels are relatively high. This indicate increased levels of nutrients in the forests. On the other hand, sensitive lichen species had become more common particularly in the central parts of the country, which is in agreement with decreasing sulphur deposition. The climate, tree species, stand age etc., however, mainly determining the distribution and the abundance of epiphytic lichens in Finland.

Green algae have become considerably more abundant in the years 1985–1995 in Finland and their distribution area has expanded northwards. Green algae on conifers were most abundant in southern Finland where the nitrogen deposition is highest. Correlations were observed between the abundance of green algae and a modelled nitrogen and sulphur deposition as well as the nitrogen concentration of the biomonitors. The increased abundance of green algae in Finland may be caused by several concurrent changes which have taken place in the environment and which have all promoted the occurrence of green algae. A slight rise in mean annual temperature, the long-term stability of nitrogen deposition, and the clear fall in the amount of sulphur deposition have probably all increased the growth and abundance of green algae. At a local level, the differences in microclimate have also effect on the abundance of green algae and the microclimate varies, inter alia, by the nutrient-richness of the habitat, the predominant tree species, stand age and stand density.

An environmental specimen bank was built in 1994 by the Finnish Forest Research Institute. The main material stored is moss samples collected from the permanent nationwide sampling network every five years since 1985 for both national and international heavy metal surveys. Correspondingly there are nationwide biomonitoring samples of epiphytic lichen, pine bark and humus for surveying atmospheric heavy metal deposition. The bank is also storage of forest litter collected from 1960's onwards. This large material, tens of thousands of sorted samples, is valuable for indicating environmental changes of the forest ecosystem.

This study measured heavy metal and nutrient concentrations of two feather mosses during the periods of dry storage. Samples (Hylocomium splendens, Pleurozium schreberi) were collected in the nationwide moss surveys carried out on the permanent sample plots of the 8th Finnish National Forest Inventory in 1985–86, 1990, 1995 and 2000. A small amount of each moss sample was analyzed soon after collection, and the remainder was dried and stored at the Paljakka environmental specimen bank (ESB). The 108 stored samples from 27 plots were reanalyzed in 2008. Concentrations of heavy metals (Cd, Cr, Cu, Fe, Ni, Pb, Zn) and nutrients (Ca, K, Mg, P) were determined and compared for each survey year. Overall, Fe, Pb and Cr concentrations decreased, and Cu concentrations increased significantly during storage. The greatest decrease was observed in samples from plots where their initial concentrations were the highest. Changes in the concentrations of Cd, Ni and Zn were less pronounced. The loss of heavy metals is likely due to drying when cell membranes rupture and some of the surface material is lost. K, P and, to some extent, Mg concentrations increased during storage, whereas Ca did not change significantly. Nutrient increase is probably due to their movement from older to younger growths during the initial phase of drying. Ca is mostly bound to cell walls and is not easily released. Results emphasize the importance of establishing the intended use of a stored moss prior to sampling, in order to select and optimize an appropriate storage technique.

Previous analyses at the European scale have shown that cadmium and lead concentrations in mosses are primarily determined by the total deposition of these metals. Further analyses in the current study show that Spearman rank correlations between the concentration in mosses and the deposition modelled by the European Monitoring and Evaluation Programme (EMEP) are country and metal-specific. Significant positive correlations were found for about two thirds or more of the participating countries in 1990, 1995, 2000 and 2005 (except for Cd in 1990). Correlations were often not significant and sometimes negative in countries where mosses were only sampled in a relatively small number of EMEP grids. Correlations frequently improved when only data for EMEP grids with at least three moss sampling sites per grid were included. It was concluded that spatial patterns and temporal trends agree reasonably well between lead and cadmium concentrations in mosses and modelled atmospheric deposition.

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 (

Nitrogen deposition in Finland was investigated on the basis of the nitrogen concentration in the forest moss, Hylocomium splendens, collected during heavy metal moss surveys carried out in 1990, 1995, 2000, and 2005/06. Significant regional differences were found in the nitrogen concentrations in mosses. The concentrations were the highest in the southern part of the country in all the surveys, with a decreasing trend on moving northwards. The mean concentrations in the surveys were 1.07%, 1.00%, 0.89% and 0.92%. In general, the concentrations in mosses reflected nitrogen deposition at the level of the whole country. However, they did not correlate very well with the modelled nitrogen deposition because of the high local variation in the nitrogen concentration in H. splendens. One reason for the high variation was the effect of the structure of the tree stand on nitrogen concentrations in H. splendens.