Austria has been participating in the “European Moss Survey” within the UN-ECE ICP-vegetation since 1991. Three consecutive sampling periods in 1995, 2000 and 2005 were performed. Five moss species ...at 220 sampling sites (2.5 sites
1000
km
−2) were analysed for Al, As, Cd, Co, Cr, Cu, Fe, Hg, Ni, Mo, Pb, V, and Zn concentrations. According to the retrospective analysis by 3-year-old moss segments, this investigation covered deposition in the period between 1989 and 2005. A relocation of sampling sites (within 2
km
2) was necessary for <10% of the sites within the overall period. On an Austria-wide scale all metals with the exception of Co, Cd and Hg showed a significant decrease of concentrations in the observed period. On a regional or site scale a large deviation from this general trend could be found, leading to significant differences between regions for many elements (e.g. for Co, Pb and Zn). Even continuous increases of metal deposition could be found at several sites (e.g. for Mo and Cu). This implies that pollution levels at different scales should be looked at in a differentiated way even in times of generally decreasing metal deposition.
The moss and liverwort flora of Zackenberg valley in the Northeast Greenland National Park has been studied based on field investigations and literature survey. Altogether 212 taxa are recorded in ...the area, with 43 liverworts and 169 mosses. Five taxa are reported as new to Greenland Lophochaete fryei (Perss.) R.M. Schust., Sphagnum orientale L.I. Savicz, Orthothecium lapponicum (Schimp.) C. Hartm., Pohlia vexans (Limpr.) H. Lindb. and Tortella alpicola Dixon. Additionally four taxa are reported as new to east Greenland; Grimmia plagiopodia Hedw., Riccardia latifrons (Lindb.) Lindb. Sphagnum olafii Flatberg and Tritomaria exsectiformis (Breidl.) Schiffner ex Loeske. The bryophyte flora of the Zackenberg valley is characterised by pioneer species adapted to disturbance by frost and wind, but also more stable communities exist especially at the lower part of the valley with wet to moist tundra. The Zackenberg valley bryophyte flora shows higher similarity with the flora on Svalbard (81%) compared with Ellesmere Island (67% and 60% for liverworts and mosses, respectively). This is consistent with east Greenland and Svalbard belonging to the North Atlantic Arctic flora province while Ellesmere Island belongs to the Canadian Arctic flora province.
In the period between 1999 and 2000 epiphytic bryophytes were taken as bioindicators for air pollution by use of the IAP method (Index of Atmospheric Purity) and the VDI method within the Association ...of Engineers standards list (adapted from guideline 3799, 1995) in the heavy industrialized town of Linz, Austria. 52 study sites (265 trees) were analysed regarding species richness, coverage, and vitality. Q-values (sensitivity factors), calculated for each species showed significant differences for the various host tree species. The results gained by the IAP and the VDI methods were diverse, regarding the various sites where only 25% were classified identical. These differences can mainly be attributed to the differing host tree species and the size of the recording area on the various trees. Clusters of similar pollution levels were calculated and drawn as maps for both methods tested. Comparing the results of the IAP and the VDI methods with data derived from technical measurements (SO₂, NO, NO₂, and dust) a correlation between IAP-indices and SO₂ concentrations could be observed. No correlation was detected between the results derived from VDI recording and for NO, NO₂, and dust.
The aim of this study was, for the first time ever, to thoroughly identify the factors influencing Cd, Hg and Pb concentrations in mosses sampled within the framework of the European Heavy Metals in ...Mosses Surveys 1990-2005. These investigations can be seen as a follow up of a previous study where only the moss data recorded in the survey 2005 was included in the analysis (Schröder et al. 2010). The analyses of this investigation give a complete overview on the statistical association of Cd, Hg and Pb concentrations in mosses and sampling site-specific and regional characteristics, encompassing data from 4661 (1990), 7301 (1995), 6764 (2000) and 5600 (2005) sampling sites across Europe. From the many metals monitored in the European moss surveys, Cd, Hg and Pb were used as examples, since only for these three metals deposition measurements are being recorded in the framework of the European Monitoring and Evaluation Programme (EMEP). As exemplary case studies revealed that other factors besides atmospheric deposition of metals influence the element concentrations in mosses, the moss datasets of the above mentioned surveys were analysed by means of bivariate statistics and decision tree analysis in order to identify factors influencing metal bioaccumulation. In the analyses we used the metadata recorded during the sampling as well as additional geodata on, e.g., depositions, emissions and land use. Bivariate Spearman correlation analyses showed the highest correlations between Cd and Pb concentrations in mosses and EMEP modelled total deposition data (0.62 ≤ rs ≤ 0.73). For Hg the correlations with all the tested factors were considerably lower (e.g. total deposition r s ≤ 0.24). Decision tree analyses by means of Classification and Regression Trees (CART) identified the total deposition as the statistically most significant factor for the Cd and Pb concentrations in the mosses in all four monitoring campaigns. For Hg, the most significant factor in 1990 as identified by CART was the distance to the nearest Hg source recorded in the European Pollutant Emission Register, in 1995 and 2000 it was the analytical method, and in 2005 it was the sampled moss species. The strong correlations between the Cd and Pb concentrations in the mosses and the total deposition can be used to calculate deposition maps with a regression kriging approach on the basis of surface maps on the element concentrations in the mosses.
To evaluate a new N-monitoring program in the framework of the UN-ECE ICP-Vegetation program using mosses as bioindicators, 490 moss samples were collected at 220 sites in Austria and analyzed for ...total N (N content) and δ15N signatures. Within-site variability of N content and δ15N signatures was tested for the first time on a large scale and was extremely low compared to between-site variability. N content in moss tissue ranged between 0.76% and 1.99% and δ15N signatures between −10.04 and −2.45. Altitude was significantly correlated with N content (P = 0.021) and δ15N signatures (P < 0.001). When comparing moss data to deposition data from 35 measurement sites, significant correlations between N content and N deposition (P = 0.014) were found. Increasing δ15N signatures provided evidence for a change in N source and its respective isotopic composition with altitude, e.g., due to long-distance transport of reactive N or as a result of changes in the wet:dry deposition ratio. Our study underlines that N deposition can generally be estimated by N content in mosses on a large scale, but that this approach has certain limitations, especially in areas with large differences in altitude and precipitation.
We evaluated the effect of acidic deposition and nitrogen on Austrian forests soils. Until thirty years ago air pollution had led to soil acidification, and concerns on the future productivity of ...forests were raised. Elevated rates of nitrogen deposition were believed to cause nitrate leaching and imbalanced forest nutrition. We used data from a soil monitoring network to evaluate the trends and current status of the pH and the C : N ratio of Austrian forest soils. Deposition measurements and nitrogen contents of Norway spruce needles and mosses were used to assess the nitrogen supply. The pH values of soils have increased because of decreasing proton depositions caused by reduction of emissions. The C : N ratio of Austrian forest soils is widening. Despite high nitrogen deposition rates the increase in forest stand density and productivity has increased the nitrogen demand. The Austrian Bioindicator Grid shows that forest ecosystems are still deficient in nitrogen. Soils retain nitrogen efficiently, and nitrate leaching into the groundwater is presently not a large-scale problem. The decline of soil acidity and the deposition of nitrogen together with climate change effects will further increase the productivity of the forests until a limiting factor such as water scarcity becomes effective.
•Epixylic bryophyte diversity increased strongly up to 60 m3 of deadwood per hectare.•Obligate epixylic bryophytes occurred only above 900 mm of annual precipitation.•Deadwood-specific specialists ...benefited from the wettest conditions.•Conserving substrate-specific communities needs both enough deadwood and rainfall.•Characteristic deadwood-dwelling liverworts face the highest risk of climate change.
Deadwood is a habitat for numerous biota and serves as an indicator of forest biodiversity. Bryophytes significantly contribute to deadwood communities and epixylic bryophytes are particularly threatened. Additional to deadwood volumes, their occurrence depends on climatic conditions. However, the interactive effects of deadwood and climate on epixylic bryophytes have hardly been assessed. Here, we analyse these effects based on 8 143 bryophyte specimens collected on 510 logs in 51 Austrian forests. We found that annual precipitation sum and deadwood volume explained 67%, 90%, and 82% of the variation in moss, liverwort and total species richness, respectively. Segmented regression indicated several breakpoints in these relationships, especially at c. 60 m3/ha of deadwood and 900 mm, respectively 1700 mm of annual precipitation. Epixylic bryophyte diversity increased strongly up to the deadwood threshold, but only moderately with still higher volumes. Nine hundred mm of annual precipitation was a macroclimatic limit for deadwood-specific bryophyte species. Below this value, obligate epixylic bryophytes were lost and liverworts were rare, even at sites with high deadwood amounts. At the wettest sites, the overall number of species decreased while deadwood-specific specialists further increased in number. The close tie of epixylic bryophytes to macroclimate may constrain the efficiency of deadwood management measures and suggests considerable impacts of climate change. A drier and warmer climate will probably decrease species richness and change the composition of epixylic bryophyte communities, with the most characteristic species, especially liverworts, facing the highest risk.
Question: Is Rhynchostegium megapolitanum an expanding species? Location: Viennese Basin (120–220 m a.s.l.), Austria. Methods: 121 dry grasslands, were investigated for the occurrence of R. ...megapolitanum. Nineteen environmental variables at 50 randomly selected sites, species composition at sites with and without R. megapolitanum and the spatial patterns of distribution of the species at the landscape scale were analysed. We compared actual distribution data of three rare species (Didymodon acutus, Pleurochaete squarrosa R. megapolitanum) and a common one (Brachythecium rutabulum) with the distribution obtained by vouchers that were collected between 1860 and 1940 in the investigated area. We calculated a GIS based model pattern and compared it with the actual distribution. Results: R. megapolitanum was detected in 28 of these sites, almost 50 % of its populations produced sporophytes. We found significant differences between sites with and without R. megapolitanum with regard to grassland size, the percentage of silt and of sand in the soil. There were fewer occurrences of historic herbarium vouchers of R. megapolitanum than our current field survey discovered. The GIS based analyses of distribution patterns at the landscape scale showed a clustering of sites in which R. megapolitanum was present or absent. Simulations with a spatially realistic expansion model showed high similarities to the actual distribution of the species. Conclusions: All these analyses suggest that R. megapolitanum has been expanding in the investigated area. A significant increase in temperature and nitrogen deposition within the last hundred years might be the underlying cause for the species' spread. Nomenclatural reference: For bryophyte species Corley et al. (1981); for vascular plants Adler et al. (1994). Abbreviations AFLP = Amplified Fragment Length Polymorphism; GIS = Geographic information system; NHM = Natural History Museum Vienna; ZAMG = Central Institute of Meteorology and Geodynamics
At four industrial regions, heavy metal concentrations and calculated depositions were investigated by sampling and analysing mosses. In each region, a special spatial pattern of heavy metal ...concentrations was detected, reflecting the industrial processes. Metals most likely originating from the industrial sites showed an exponential decrease of concentrations and depositions with increasing distance from the pollution source. The exponential deposition pattern was in some cases modified by a series of natural factors, like the main direction of winds or orographic conditions. The distance at which deposition dropped to background values was up to 20 km. Beside the fact that the "moss-metho" is a useful tool for deposition measurement in the vicinity of stationary sources, some improvements for using this method are discussed, highlighting factors such as a proper calculation of deposition from concentrations, or the better knowledge of correlations between heavy metal concentrations in mosses and effects on human health.PUBLICATION ABSTRACT
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