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1.
Projected climate change might increase the deposition of nitrogen by about 10% to seminatural ecosystems in southern Norway. At Storgama, increased precipitation in the growing season increased the fluxes of total organic carbon (TOC) and total organic nitrogen (TON) in proportion to the water flux. In winter, soil temperatures near 0 degrees C, common under a snowpack, induced higher runoff of inorganic nitrogen (N) and lower runoff of TOC. By contrast, soil temperatures below freezing, caused by little snow accumulation (expected in a warmer world), reduced runoff of inorganic N, TON, and TOC. Long-term monitoring data showed that reduced snowpack can cause either decreased or increased N leaching, depending on interactions with N deposition, soil temperature regime, and winter discharge. Seasonal variation in TOC was mainly climatically controlled, whereas deposition of sulfate and nitrate (NO3) explained the long-term TOC increase. Upscaling to the river basin scale showed that the annual flux of NO3 will remain unchanged in response to climate change projections. 相似文献
2.
Hole LR Brunner SH Hanssen JE Zhang L 《Environmental pollution (Barking, Essex : 1987)》2008,154(3):473-481
The conditional time averaged gradient method was used to measure air-surface exchange of nitrogen and sulphur compounds at a semi-alpine site in Southern Norway. Dry deposition velocities were then obtained from the bi-weekly concentration gradient measurements. Annual deposition velocities were found to be 1.4, 11.8 and 4.0 mm s(-1) for NH3, HNO3 and SO2, respectively, if all data were included, and to be 10.8, 11.8 and 13.0 mm s(-1), respectively, if only positive values were included. Measured deposition velocities were compared to two sets of values estimated from a big-leaf dry deposition module applying to two different land types (short grass and forbs, and tundra), driven by measured micrometeorological parameters. The deposition module gives reasonable values for this site throughout the year, but does not reproduce the large variability as shown in the measured data. No apparent seasonal variations were found from either measurements or module estimates due to the very low productivity of the studied area. 相似文献
3.
Martin Forsius Maximilian Posch Julian Aherne Gert Jan Reinds Jesper Christensen Lars Hole 《Ambio》2010,39(2):136-147
For more than a decade, anthropogenic sulfur (S) and nitrogen (N) deposition has been identified as a key pollutant in the
Arctic. In this study new critical loads of acidity (S and N) were estimated for terrestrial ecosystems north of 60° latitude
by applying the Simple Mass Balance (SMB) model using two critical chemical criteria (Al/Bc = 1 and ANCle = 0). Critical loads were exceeded in large areas of northern Europe and the Norilsk region in western Siberia during the
1990s, with the more stringent criterion (ANCle = 0) showing the larger area of exceedance. However, modeled deposition estimates indicate that mean concentrations of sulfur
oxides and total S deposition within the Arctic almost halved between 1990 and 2000. The modeled exceeded area is much reduced
when currently agreed emission reductions are applied, and almost disappears under the implementation of maximum technically
feasible reductions by 2020. In northern North America there was no exceedance under any of the deposition scenarios applied.
Modeled N deposition was less than 5 kg ha−1 y−1 almost across the entire study area for all scenarios; and therefore empirical critical loads for the eutrophying impact
of nitrogen are unlikely to be exceeded. The reduction in critical load exceedances is supported by observed improvements
in surface water quality, whereas the observed extensive damage of terrestrial vegetation around the mining and smelter complexes
in the area is mainly caused by direct impacts of air pollution and metals. 相似文献
4.
Martina Galdíková Katarína Šiviková Beáta Holečková Ján Dianovský Monika Drážovská Viera Schwarzbacherová 《Journal of environmental science and health. Part. B》2013,48(10):698-707
The potential genotoxic effect of thiacloprid formulation on bovine peripheral lymphocytes was evaluated using the comet assay and the cytogenetic endpoints: chromosome aberrations (CAs), sister chromatid exchanges (SCEs) and micronuclei (MNi). Whole blood cultures were treated with the insecticide at concentrations of 30, 60, 120, 240 and 480 μg mL?1 for 24, 48 h and/or 2 h of incubation. A statistically significant increase in the frequency of DNA damage, as well as in unstable chromosome aberrations (% breaks) were found after exposure to the insecticide at concentrations ranging from 120 to 480 μg mL?1 (P < 0.05, P < 0.01, P < 0.001). For the detection of stable structural chromosome aberrations (e.g., translocations) and numerical aberrations by the FISH method, three whole chromosome painting probes for bovine chromosomes 1, 5 and 7 (BTA1, BTA5 and BTA7) were used in our experiments. We observed numerical aberrations, but without any statistical significance. Regarding the sister chromatid exchanges, no significant elevation in the SCE frequencies was found after 24-h exposure to the insecticide. A dose-related response in the SCE induction was obtained in bovine cultures after the prolonged time of exposure (48 h) to thiacloprid formulation at concentrations ranging from 120 to 480 μg mL?1 in each donor (P < 0.05, P < 0.01), which was associated with a reduction of the PI (P < 0.05, P < 0.01). The insecticide failed to produce MNi; however, a significant reduction of CBPI was observed. Using real-time PCR, a decrease in the expression of bovine glutathione S-transferase M3 (GSTM3) was detected at the lowest dose. The higher concentrations of thiacloprid formulation caused an increase in the mRNA expression. 相似文献
5.
Krista M.S. Kemppinen Pamela M. Collins David G. Hole Christopher Wolf William J. Ripple Leah R. Gerber 《Conservation biology》2020,34(5):1221-1228
The loss of forest is a leading cause of species extinction, and reforestation is 1 of 2 established interventions for reversing this loss. However, the role of reforestation for biodiversity conservation remains debated, and lacking is an assessment of the potential contribution that reforestation could make to biodiversity conservation globally. We conducted a spatial analysis of overlap between 1,550 forest-obligate threatened species’ ranges and land that could be reforested after accounting for socioeconomic and ecological constraints. Reforestation on at least 43% (∼369 million ha) of reforestable area was predicted to potentially benefit threatened vertebrates. This is approximately 15% of the total area where threatened vertebrates occur. The greatest opportunities for conserving threatened vertebrate species are in the tropics, particularly Brazil and Indonesia. Although reforestation is not a substitute for forest conservation, and most of the area containing threatened vertebrates remains forested, our results highlight the need for global conservation strategies to recognize the potentially significant contribution that reforestation could make to biodiversity conservation. If implemented, reforestation of ∼369 million ha would also contribute substantially to climate-change mitigation, offering a way to achieve multiple sustainability commitments at once. Countries must now work to overcome key barriers (e.g., unclear revenue streams, high transaction costs) to investment in reforestation. 相似文献
6.
Lars R. Hole Jesper H. Christensen Tuija Ruoho-Airola Kjetil Tørseth Veronica Ginzburg Piotr Glowacki 《Atmospheric environment (Oxford, England : 1994)》2009,43(4):928-939
Recent trends in nitrogen and sulphur compounds in air and precipitation from a range of Arctic monitoring stations are presented, with seasonal data from the late 70s to 2004 or 2005. Earlier findings of declining sulphur concentrations are confirmed for most stations, while the pattern is less clear for reduced and oxidized nitrogen. In fact there are positive trends for nitrogen compounds in air at several stations. Acidity is generally reduced at many stations while the precipitation amount is either increasing or stable. Variability of sulphate concentrations in air for the period 1991–2000 is reasonably well reproduced at most stations using an Eulerian, hemispherical model. Results for nitrogen compounds are weaker. Scenario studies show that even if large sulphur emission reductions take place in important source regions in South-East Asia in the coming decades, only small changes in Arctic deposition can be expected. This is because South-East Asian emissions have small influence north of the Arctic circle. 相似文献
7.
Anne Orderdalen Steen Torunn Berg Ashu P. Dastoor Dorothy A. Durnford Lars Robert Hole Katrine Aspmo Pfaffhuber 《Atmospheric environment (Oxford, England : 1994)》2009,43(35):5604-5610
From February 29 until June 15 2008 gaseous elemental mercury (GEM) fluxes above a snow covered surface was measured in Ny-Ålesund, Svalbard using a GEM flux gradient method. A clear seasonal pattern in the meteorological variables associated with the GEM flux was observed. For the first time in Ny-Ålesund a net deposition of GEM was recorded during polar night, despite the lack of Atmospheric Mercury Depletion Events (AMDE). 7500 ng m−2 GEM was emitted from the surface snow to the air during the entire study. The depositions of GEM and reactive gaseous mercury (RGM) were calculated to be 1500 and 1000 ng m−2, respectively, during the same time period. The GEM fluxes reported in this study were found to be comparable to GEM fluxes measured at other Arctic locations (i.e. Alert and Barrow), suggesting that GEM acts in a similar way throughout the Arctic. An assessment of the GEM flux gradient method used discovered a non-linear GEM concentration profile. The nonlinearity was explained by a non-stationary turbulence regime. The GEM flux calculated was not found to be representative for the entire surface boundary layer. 相似文献
8.
Willis SG Hole DG Collingham YC Hilton G Rahbek C Huntley B 《Environmental management》2009,43(5):836-845
Global climate change, along with continued habitat loss and fragmentation, is now recognized as being a major threat to future
biodiversity. There is a very real threat to species, arising from the need to shift their ranges in the future to track regions
of suitable climate. The Important Bird Area (IBA) network is a series of sites designed to conserve avian diversity in the
face of current threats from factors such as habitat loss and fragmentation. However, in common with other networks, the IBA
network is based on the assumption that the climate will remain unchanged in the future. In this article, we provide a method
to simulate the occurrence of species of conservation concern in protected areas, which could be used as a first-step approach
to assess the potential impacts of climate change upon such species in protected areas. We use species-climate response surface
models to relate the occurrence of 12 biome-restricted African species to climate data at a coarse (quarter degree-degree
latitude-longitude) resolution and then intersect the grid model output with IBA outlines to simulate the occurrence of the
species in South African IBAs. Our results demonstrate that this relatively simple technique provides good simulations of
current species' occurrence in protected areas. We then use basic habitat data for IBAs along with habitat preference data
for the species to reduce over-prediction and further improve predictive ability. This approach can be used with future climate
change scenarios to highlight vulnerable species in IBAs in the future and allow practical recommendations to be made to enhance
the IBA network and minimize the predicted impacts of climate change. 相似文献
9.
Beáta Holečková Katarína Šiviková Ján Dianovský Martina Galdíková 《Journal of environmental science and health. Part. B》2013,48(12):1080-1088
To date, most data about the possible genotoxic effect of triazole pesticides are focused on laboratory animals resulting in limited information on further non-target organisms such as cattle. The objective of the present study was to investigate the effect of triazole (tebuconazole/prothioconazole) fungicide formulation on the induction of chromosomal aberrations (CAs), sister chromatid exchanges (SCEs) and DNA fragmentation in bovine cultured lymphocytes. Our results showed that the fungicide formulation did not induce significant number of CAs in bovine cells after 24 h treatment. Nevertheless, the dose-dependent reduction of mitotic division was observed, with the strongest effect at 30.0 μg mL?1 in both donors (P < 0.01 and P < 0.001, respectively). Prolonged 48 h exposure caused the increased level of breaks in treated cultures (3.0?15.0 μg mL?1; P < 0.05) and significant decrease in mitotic index (MI). The tested fungicide failed to produce any statistical changes in the SCE frequency neither after 24 h nor 48 h treatment. However, the significant decline of the proliferation index (PI) was observed after 24 h indicating the fungicide influence on cell cycle kinetics. Prolonged 48 h exposure caused cytotoxicity reflecting in lower PI value relative to control mainly at the highest fungicide concentrations (30.0 μg mL?1, P < 0.001). Using painting probes for bovine chromosomes 1, 5 and 7 (BTA1, BTA5 and BTA7) only low levels of aneuploidies were detected. Significant increase of polyploidy cells (P < 0.05) was induced by a 3.0 μg mL?1 dose of the fungicide after 48 h. DNA fragmentation assay didn't reveal the presence of DNA nucleosome ladder in cell cultures at any time (24 h and 48 h) and fungicide concentration. 相似文献
10.
Monika Drážovská Katarína Šiviková Beáta Holečková Ján Dianovský Martina Galdíková Viera Schwarzbacherová 《Journal of environmental science and health. Part. B》2016,51(11):769-776
Potential genotoxic/cytotoxic effects of the epoxiconazole/fenpropimorph-based fungicide were investigated using single cell gel electrophoresis and cytogenetic assays: chromosomal aberrations, sister chromatid exchanges, micronuclei and fluorescence in situ hybridization in cultured bovine lymphocytes. No statistically significant elevations of DNA damage and increases in cytogenetic endpoints were seen. However, evident cytotoxic effect presented as a decrease in mitotic and proliferation indices were recorded after exposure of bovine lymphocytes to the fungicide for 24 and 48 h at concentrations ranging from 3 to 15 µg mL?1 (P < 0.05, P < 0.01, P < 0.001). Similarly, for 24 h an inhibition in the cytokinesis block proliferation index (CBPI) was obtained after exposure to the fungicide at concentrations ranging from 1.5 to 15 µg mL?1 (P < 0.01, P < 0.001) in each donor. 相似文献