Tallinn, Estonia
Tallinn, Estonia

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Schroder W.,University of Vechta | Holy M.,University of Vechta | Pesch R.,University of Vechta | Harmens H.,UK Center for Ecology and Hydrology | And 18 more authors.
Atmospheric Environment | Year: 2010

In this study, the indicative value of mosses as biomonitors of atmospheric nitrogen (N) depositions and air concentrations on the one hand and site-specific and regional factors which explain best the total N concentration in mosses on the other hand were investigated for the first time at a European scale using correlation analyses. The analyses included data from mosses collected from 2781 sites across Europe within the framework of the European moss survey 2005/6, which was coordinated by the International Cooperative Programme on Effects of Air Pollution on Natural Vegetation and Crops (ICP Vegetation). Modelled atmospheric N deposition and air concentration data were calculated using the Unified EMEP Model of the European Monitoring and Evaluation Programme (EMEP) of the Convention on Long-range Transboundary Air Pollution (CLRTAP). The modelled deposition and concentration data encompass various N compounds. In order to assess the correlations between moss tissue total N concentrations and the chosen predictors, Spearman rank correlation analysis and Classification and Regression Trees (CART) were applied. The Spearman rank correlation analysis showed that the total N concentration in mosses and modelled N depositions and air concentrations are significantly correlated (0.53 ≤ rs ≤ 0.68, p < 0.001). Correlations with other predictors were lower than 0.55. The CART analysis indicated that the variation in the total N concentration in mosses was best explained by the variation in NH4 + concentrations in air, followed by NO2 concentrations in air, sampled moss species and total dry N deposition. The total N concentrations in mosses mirror land use-related atmospheric concentrations and depositions of N across Europe. In addition to already proven associations to measured N deposition on a local scale the study at hand gives a scientific prove on the association of N concentration in mosses and modelled deposition at the European scale. © 2010 Elsevier Ltd.


Harmens H.,UK Center for Ecology and Hydrology | Ilyin I.,Meteorological Synthesizing Center East of EMEP | Mills G.,UK Center for Ecology and Hydrology | Aboal J.R.,University of Santiago de Compostela | And 33 more authors.
Environmental Pollution | Year: 2012

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. © 2012 Elsevier Ltd. All rights reserved.


Godefroid S.,National Botanic Garden of Belgium | Godefroid S.,Vrije Universiteit Brussel | Godefroid S.,Roosevelt University | Piazza C.,Conservatoire Botanique National de Corse | And 18 more authors.
Biological Conservation | Year: 2011

Reintroduction of native species has become increasingly important in conservation worldwide for recovery of rare species and restoration purposes. However, few studies have reported the outcome of reintroduction efforts in plant species. Using data from the literature combined with a questionnaire survey, this paper analyses 249 plant species reintroductions worldwide by assessing the methods used and the results obtained from these reintroduction experiments. The objectives were: (1) to examine how successful plant species reintroductions have been so far in establishing or significantly augmenting viable, self-sustaining populations in nature; (2) to determine the conditions under which we might expect plant species reintroductions to be most successful; (3) to make the results of this survey available for future plant reintroduction trials. Results indicate that survival, flowering and fruiting rates of reintroduced plants are generally quite low (on average 52%, 19% and 16%, respectively). Furthermore, our results show a success rate decline in individual experiments with time. Survival rates reported in the literature are also much higher (78% on average) than those mentioned by survey participants (33% on average). We identified various parameters that positively influence plant reintroduction outcomes, e.g., working in protected sites, using seedlings, increasing the number of reintroduced individuals, mixing material from diverse populations, using transplants from stable source populations, site preparation or management effort and knowledge of the genetic variation of the target species. This study also revealed shortcomings of common experimental designs that greatly limit the interpretation of plant reintroduction studies: (1) insufficient monitoring following reintroduction (usually ceasing after 4 years); (2) inadequate documentation, which is especially acute for reintroductions that are regarded as failures; (3) lack of understanding of the underlying reasons for decline in existing plant populations; (4) overly optimistic evaluation of success based on short-term results; and (5) poorly defined success criteria for reintroduction projects. We therefore conclude that the value of plant reintroductions as a conservation tool could be improved by: (1) an increased focus on species biology; (2) using a higher number of transplants (preferring seedlings rather than seeds); (3) taking better account of seed production and recruitment when assessing the success of reintroductions; (4) a consistent long-term monitoring after reintroduction. © 2010 Elsevier Ltd.


Harmens H.,UK Center for Ecology and Hydrology | Norris D.A.,UK Center for Ecology and Hydrology | Cooper D.M.,UK Center for Ecology and Hydrology | Mills G.,UK Center for Ecology and Hydrology | And 23 more authors.
Environmental Pollution | Year: 2011

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 × 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 (r 2 = 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. © 2010 Published by Elsevier Ltd.


Harmens H.,UK Center for Ecology and Hydrology | Norris D.A.,UK Center for Ecology and Hydrology | Steinnes E.,Norwegian University of Science and Technology | Kubin E.,Finnish Forest Research Institute | And 30 more authors.
Environmental Pollution | Year: 2010

In recent decades, mosses have been used successfully as biomonitors of atmospheric deposition of heavy metals. Since 1990, the European moss survey has been repeated at five-yearly intervals. Although spatial patterns were metal-specific, in 2005 the lowest concentrations of metals in mosses were generally found in Scandinavia, the Baltic States and northern parts of the UK; the highest concentrations were generally found in Belgium and south-eastern Europe. The recent decline in emission and subsequent deposition of heavy metals across Europe has resulted in a decrease in the heavy metal concentration in mosses for the majority of metals. Since 1990, the concentration in mosses has declined the most for arsenic, cadmium, iron, lead and vanadium (52-72%), followed by copper, nickel and zinc (20-30%), with no significant reduction being observed for mercury (12% since 1995) and chromium (2%). However, temporal trends were country-specific with sometimes increases being found. © 2010 Elsevier Ltd. All rights reserved.


PubMed | University of Tirana, University of Galati, University Valahia of Targoviste, University of Vienna and 27 more.
Type: | Journal: Environmental pollution (Barking, Essex : 1987) | Year: 2015

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.


PubMed | University of Tirana, National Museum of Natural History, University Valahia of Targoviste, University of Vienna and 26 more.
Type: Journal Article | Journal: Environmental science and pollution research international | Year: 2016

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 5years 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 (1990-2010); (3) correlations between concentrations of HM in moss and soil specimens collected across Norway (1990-2010); and (4) canopy drip-induced site-specific variation of N concentration in moss sampled in seven European countries (1990-2013). 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.


Napa U.,University of Tartu | Kabral N.,University of Tartu | Kabral N.,Estonian Environmental Research Center | Liiv S.,Tallinn Botanic Garden | And 3 more authors.
Ecological Indicators | Year: 2015

In order to characterise current and historical pattern of heavy metal (HM) pollution in Estonia, this article will compare the concentrations and stocks of Cd, Cr, Cu, Ni, Pb and Zn represented in current deposition (data from 18 local precipitation stations) with natural media of three different ages: 1-3-year-old moss carpet (ICP Vegetation moss survey data from 99 open area plots), 3-5-year-old litter layer, and several-decades-old organic layer (mor humus) of coniferous forest, in mostly podzolic soils (ICP Forest soil survey data, 75 stands). Objectives of this study are (1) to assess differences in HM retention and accumulation in various aged media of coniferous stands (2) to estimate territorial differences in current HM distribution and previously accumulated concentrations and stores of HM (3) to compare territorial distribution of HM concentration in Estonia between five different regions: N-W; N-E; S-W; S-E and Western insular region, whereas the local oil shale industry in N-E part of Estonia has been the main source of HM pollution over a long period of time and therefore may have an effect on HM regional distribution. Comparing the studied media, three types of HM retention patterns were detected: (1) for Cu, Ni, Cr (2) for Cd, Pb, (3) for Zn. The mean current level of HM deposition in Estonia is low comparison to previous decades, especially the 1980s. The effect of the previously significantly higher exposure of HM emissions and deposition is preserved in older part of soil organics (OF), where the highest stocks and concentrations of HMs (with the exception of Zn) are currently found. The HM proportions in fly ash of oil shale and in OF layer of soil were very similar with regards to Ni and Cr - indicating their origin from the oil shale industry in the N-E region. According to spatial distribution analysis, the greatest accumulated storages of Ni and Cr in OF layer of coniferous forest soils are characteristic to S-W Estonia. © 2014 Elsevier Ltd.


Lorence D.H.,National Tropical Botanical Garden | Wood K.R.,National Tropical Botanical Garden | Aguraiuja R.,Tallinn Botanic Garden
American Fern Journal | Year: 2013

Morphological variation of three Kaua'i species of Asplenium in the Diellia alliance is evaluated based on recent field observations and herbarium specimens. Their taxonomy, nomenclature, and synonymy are discussed, and a lectotype is selected for Lindsaya knudsenii. Asplenium diellaciniatum is interpreted as having extremely variable frond morphology and dissection, whereas A. dielmannii and A. dielpallidum are morphologically much more uniform. Their conservation status and population sizes are reviewed. © 2013, American Fern Society.


Aguraiuja R.,Tallinn Botanic Garden
Biodiversity and Conservation | Year: 2011

Woodsia ilvensis has become extinct from its last known natural localities in Estonia and has not been rediscovered since 1977. This fern grew in northern and north-western Estonia in areas of suitable habitat. Considering that habitat conditions may have changed in previous localities, an experimental project was started to test if it would be possible to reintroduce W. ilvensis into new localities where suitable habitat conditions exist. Two experiments were performed, one on an old stone wall, constructed of stones collected from the surrounding fields, and another on two granite boulders in two localities, one where the surrounding soil was acidic, and the other where the soil was basic. The plants were grown from spores of wild provenance received from Finland via the seed and spore exchange system of botanical gardens. Results confirmed that individual plants can establish and persist for at least 10 years on stone walls without maintenance. The experiment on boulders failed, as plants did not establish there. Young, 2-year old mature individuals proved to be the best stage for planting out onto the stone walls in this case study. The best indicators for selecting suitable habitat were characteristic plant species of the natural community. Here I discuss the experimental methods used and first results of the experiment. © 2010 Springer Science+Business Media B.V.

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