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  • 1
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Environmental Pollution 85 (1994), S. 153-160 
    ISSN: 0269-7491
    Keywords: grey seal ; harbour seal ; harp seal ; mercury ; ringed seal ; selenium
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Energy, Environment Protection, Nuclear Power Engineering
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  • 2
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    Amsterdam : Elsevier
    Radiation Physics and Chemistry 42 (1993), S. 993-996 
    ISSN: 0969-806X
    Keywords: acceleration ; argon ; beta particles ; drift ; electric field ; electrons ; excited states ; ion mobility ; ions mobility ; nitrogen ; reactive species
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Chemistry and Pharmacology , Energy, Environment Protection, Nuclear Power Engineering , Physics
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  • 3
    ISSN: 1539-6924
    Keywords: Benchmark ; mercury ; risk assessment ; epidemiology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract This paper presents benchmark (BMD) calculations and additional regression analyses of data from a study in which scores from 26 scholastic and psychological tests administered to 237 6- and 7-year-old New Zealand children were correlated with the mercury concentration in their mothers' hair during pregnancy. The original analyses of five test scores found an association between high prenatal mercury exposure and decreased test performance, using category variables for mercury exposure. Our regression analyses, which utilized the actual hair mercury level, did not find significant associations between mercury and children's test scores. However, this finding was highly influenced by a single child whose mother's mercury hair level (86 mg/kg) was more than four times that of any other mother. When that child was omitted, results were more indicative of a mercury effect and scores on six tests were significantly associated with the mothers' hair mercury level. BMDs calculated from five tests ranged from 32 to 73 mg/kg hair mercury, and corresponding BMDLs (95% lower limits on BMDs) ranged from 17 to 24 mg/kg. When the child with the highest mercury level was omitted, BMDs ranged from 13 to 21 mg/kg, and corresponding BMDLs ranged from 7.4 to 10 mg/kg.
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  • 4
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    Springer
    Biodegradation 14 (1991), S. 167-191 
    ISSN: 1572-9729
    Keywords: leaf longevity ; nitrogen ; nutrient use efficiency ; phosphorus ; requirement ; retranslocation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Aboveground nitrogen (N) and phosphorus (P) requirement, retranslocation and use efficiency were determined for 28-year-old red oak (Quercus rubra L.), European larch (Larix decidua Miller), white pine (Pinus strobes L.), red pine (Pinus resinosa Ait.) and Norway spruce (Picea abies (L) Karst.) plantations on a similar soil in southwestern Wisconsin. Annual aboveground N and P requirements (kg/ha/yr) totaled 126 and 13 for red oak, 86 and 9 for European larch, 80 and 9 for white pine, 38 and 6 for red pine, and 81 and 13 for Norway spruce, respectively. Nitrogen and P retranslocation from current foliage ranged from 81 and 72%, respectively, for European larch, whereas red pine retranslocated the smallest amount of N (13%) and Norway spruce retranslocated the smallest amount of P (18%). In three evergreen species, uptake accounted for 72 to 74% of annual N requirement whereas for two deciduous species retranslocation accounted for 76 to 77% of the annual N requirement. Nitrogen and P use (ANPP/uptake) was more efficient in deciduous species than evergreen species. The results from this common garden experiment demonstrate that differences in N and P cycling among species may result from intrinsic characteristics (e.g. leaf longevity) rather than environmental conditions.
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  • 5
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    Biodegradation 14 (1991), S. 209-224 
    ISSN: 1572-9729
    Keywords: ground water ; hydrology ; nitrogen ; mass balance ; nutrient retention ; swamp
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Ground water inputs and outputs of N were studied for a small ground water discharge swamp situated in a headwater drainage basin in southern Ontario, Canada. Darcy's equation with data for piezometers was used to measure inputs of shallow local ground water at the swamp margin and deep regional ground water beneath the swamp. Ground water flux was also quantified by measuring ground water discharge to the outlet stream draining the swamp in combination with a chemical mixing model to separate shallow and deep ground water components based on chloride differences. Estimates of shallow ground water flux determined by these two approaches agreed closely however, the piezometer data seriously underestimated the deep ground water input to the swamp. An average ground water input-output budget of total N (TN) total organic nitrogen (TON) ammonium (NH4 +-N) and nitrate (NO3 --N) was estimated for stream base flow periods which occurred on an average of 328 days each year during 1986–1990. Approximately 90% of the annual NO3 --N input was contributed by shallow ground water at the swamp margin. Deep ground water represented about 65% of the total ground water input and a similar proportion of TON and NH4 +-N inputs. Annual ground water NO3 --N inputs and outputs were similar whereas NH4 +-N retention was 4 kg ha-1 representing about 68% of annual ground water input. Annual TON inputs in ground water exceeded outputs by 7.7 kg ha (27%). The capacity of the swamp to regulate ground water N fluxes was influenced by the N chemistry of ground water inputs and the hydrologic pathways of transport within the swamp.
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  • 6
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    Human ecology 13 (1985), S. 209-240 
    ISSN: 1572-9915
    Keywords: catchment-ecosystem ; nutrient-budget ; anthropogenic inputs ; nitrogen ; phosphorus ; eutrophication ; agricultural policies
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Ethnic Sciences
    Notes: Abstract The catchment-ecosystem concept is adapted to investigate the nutrient-budget of the highly-modified Colebrooke drainage basin in Northern Ireland. Anthropogenic inputs, mainly manures and fertilizers, account for 86% of the nitrogen and 96% of the phosphorus added to the catchment. These inputs greatly exceed the streamflow outputs, thereby indicating that the flow of nutrients is dominated by agriculture. This is explained by the transformation of traditional mixed farming into more intensive livestock production and is linked to policies encouraging increased agricultural production, amalgamation of farms, afforestation, rural depopulation, and urbanization. Substantial increases in the Nand Poutput of the catchment and further eutrophication of the recipient lake, Lough Erne, are predicted without the implementation of policies to reduce agricultural nutrient losses.
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  • 7
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    Biodegradation 20 (1993), S. 195-212 
    ISSN: 1572-9729
    Keywords: denitrification ; lake ; mass balance ; nitrogen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Nitrogen mass balances for seven unproductive lakes and 20 forested catchments in central Ontario were measured between 1977 and 1989. Average annual lake denitrification rates calculated with the N/P ratio method were strongly correlated with summer anoxic factor (extent of surficial sediment anoxia) whereas denitrification rates calculated with a210Pb sediment N accumulation method were poorly correlated with the anoxic factor suggesting that the N/P method is superior. Substantial denitrification occurred in all lakes — an average of 36% of TN inputs or 75% of the net gain. On a regional area-weighted basis, 67% of bulk atmospheric TN deposition was stored or denitrified terrestrially, 12% was denitrified in lakes, 4% was stored in lake sediments, and 17% was exported from lakes. N/P ratios were generally less in streams than in precipitation suggesting preferential N retention in catchments, whereas the N/P ratios in lake outputs were slightly higher than lake input ratios, suggesting preferential P retention in lakes. This is consistent with the notion that P-limited lakes can exist adjacent to N-limited forests.
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  • 8
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    Biodegradation 10 (1990), S. 309-328 
    ISSN: 1572-9729
    Keywords: estuaries ; groundwater ; nitrogen ; nitrogen cycle ; nitrogen loading
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract We examined the importance of nitrogen inputs from groundwater and runoff in a small coastal marine cove on Cape Cod, MA, USA. We evaluated groundwater inputs by three different methods: a water budget, assuming discharge equals recharge; direct measurements of discharge using bell jars; and a budget of water and salt at the mouth of the Cove over several tidal cycles. The lowest estimates were obtained by using a water budget and the highest estimates were obtained using a budget of water and salt at the Cove mouth. Overall there was more than a five fold difference in the freshwater inputs calculated by using these methods. Nitrogen in groundwater appears to be largely derived from on site septic systems. Average nitrate concentrations were highest in the region where building density was greatest. Nitrate in groundwater appeared to behave conservatively in sandy sediments where groundwater flow rates were high (〉 11/m2/h), indicating that denitrification was not substantially reducing external nitrogen loading to the Cove. Nitrogen inputs from groundwater were approximately 300 mmol-N/m3/y of Cove water. Road runoff contributed an additional 60 mmol/m3/y. Total nitrogen inputs from groundwater and road runoff to this cove were similar in magnitude to river dominated estuaries in urbanized areas in the United States.
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  • 9
    ISSN: 1572-9729
    Keywords: calcium ; fine roots ; nitrogen ; northern hardwood ; nutrient dynamics ; seasonality ; soils ; sulfur ; vegetation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Seasonal dynamics of S, Ca and N were examined at the Huntington Forest, a northern hardwood ecosystem in the central Adirondacks of New York for a period of 34 months (1985–1988). Solute concentrations and fluxes in bulk precipitation, throughfall (TF) and leachates from the forest floor, E horizon and B horizon were quantified. Both above and below-ground elemental fluxes mediated by vegetation (e.g. uptake, litter inputs, and fine roots production) were also determined. The roles of abiotic and biotic processes were ascertained based on both changes in solute concentrations through the strata of the ecosystem as well as differences between dormant and growing seasons. Concentrations of SO4 2−, NO3 −, NH4 + and Ca2+ were greater in TF than precipitation. Forest floor leachates had greater concentrations of SO4 2−, NO3 − + NH4 + and Ca2+ (9, 6 and 77 µeq L−1, respectively) than TF. There were differences in concentrations of ions in leachates from the forest floor between the dormant and growing seasons presumably due to vegetation uptake and microbial immobilization. Concentrations and fluxes of NO3 − and NH; were greatest in early spring followed by a rapid decline which coincided with a demand for N by vegetation in late spring. Vegetation uptake (44.7 kg N ha−1 yr−1 ) could account for the low leaching rates of N03 −. Within the mineral soil, changes with soil depth and the absence of seasonal patterns suggest that cation exchange (Ca+) or anion sorption (SO4 2−) are primarily responsible for regulating solute concentrations. The increase in SO4 2− concentration after leachates passed through the mineral soil may be attributed to desorption of sulfate that was adsorbed during an earlier period when SO4 2− concentrations would have been greater due to elevated S inputs.
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  • 10
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    Biodegradation 10 (1999), S. 43-50 
    ISSN: 1572-9729
    Keywords: biodegradation ; nitrogen ; nutrients ; phenanthrene ; phosphorus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Phenanthrene mineralization rates were found to vary widely among four soils; differences in soil nutrient levels was one hypothesis to explain this variation. To test this hypothesis, phenanthrene mineralization rates were measured in these soils with, and without, added nitrogen and phosphorus. Mineralization rates either remained unchanged or were depressed by the addition of nitrogen and phosphorus. Phenanthrene degradation rates remained unchanged in the soil which had the highest indigenous levels of nitrogen and phosphorus and which showed the largest increase in phosphorus levels after nutrients were added. The soils in which degradation rates were depressed had lower initial phosphorus concentrations and showed much smaller or no measurable increase in phosphorus levels after nutrients were added to the soils. To understand the response of phenanthrene degradation rates to added nitrogen and phosphorus, it may be necessary to consider the bioavailability of added nutrients and nutrient induced changes in microbial metabolism and ecology.
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  • 11
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    Environmental and resource economics 16 (2000), S. 347-362 
    ISSN: 1573-1502
    Keywords: cost-effectiveness ; nitrogen ; nonpoint ; policy ; value ; wetlands
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Economics
    Notes: Abstract Wetlands, in Sweden and elsewhere, have been suggestedas effective and low-cost sinks for agriculturalpollution. This paper estimates the value of usingwetlands for abatement of agricultural nitrogen loadon the Baltic Sea. A replacement value of wetlands isestimated for Sweden. The replacement value is definedand estimated as the difference between twocost-effective reductions of agricultural nitrogenpollution: one that uses wetlands for nitrogenabatement, and one that does not. It is shown that theuse of wetlands as nitrogen sinks can reduce the totalabatement costs of nitrogen emissions by 30% forSwedish agricultural sources of nitrogen pollution.
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  • 12
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    Environmental and resource economics 10 (1997), S. 341-362 
    ISSN: 1573-1502
    Keywords: Baltic Sea ; eutrophication ; nitrogen ; phosphorus ; cost effective
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Economics
    Notes: Abstract Due to eutrophication caused by heavy loads of nitrogen and phosphorus, the biological conditions of the Baltic Sea have been disturbed: large sea bottom areas without any biological life, low stocks of cods, and toxic blue green algaes. It is recognized that the nitrogen and phosphorus loads to the Baltic Sea must be reduced by 50% in order to restore the sea. The main purpose of this paper is to calculate cost effective nitrogen and phosphorus reductions to the Baltic Sea from the nine countries surrounding the Baltic Sea. The results show a significant difference in minimum costs of decreasing nitrogen and phosphorus loads to the Sea: approximately 12 000 millions of SEK per year and 3 000 millions of SEK respectively for reductions by 50%. It is also shown that a change from a policy of cost-effective nutrient reductions to a policy where each country reduces the nutrient loads by 50% increase total costs for both nitrogen and phosphorus reductions by about 300%. The results are, however, sensitive to several of the underlying assumptions and should therefore be interpreted with much caution.
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  • 13
    ISSN: 1573-2932
    Keywords: nitrogen ; acidification ; Adirondack Mountains ; atmospheric deposition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Assessments of the aquatic effects of acidic deposition have focused on sulfur, as have recent efforts to control the emissions of acidifying compounds. Nitrogen dynamics were excluded from most acidic deposition modeling studies because it was believed that terrestrial ecosystems strongly retain N and because modeling N is a more formidable task than modeling S due to the influence of complex biological processes on N cycling. Re-examination of available data for the Adirondack Mountains of New York suggests that N deposition may be contributing to both chronic and episodic acidification of freshwaters to a greater extent than is generally believed. Previous research concluded that N has played a limited role in acidification processes in these lakes, based on regional averages of chronic chemistry. However, it is now known that historic acidification responses have been spatially variable within the Adirondack Mountains and that the declines in lakewater pH have been less than previously believed. Lakewater NO3 − concentrations are commonly in the range of 5 to 25 μeq L−1 on a chronic basis in portions of the Adirondack region that have experienced significant chronic acidification. These NO3 − concentrations correspond in magnitude to inferred historical acidification. Furthermore, the relative importance of NO3 − as an agent of acidification increases dramatically during snowmelt when conditions are most toxic to fish. The consequence of not addressing N in formulating acidification recovery strategies for the Adirondacks includes the likelihood that we will overestimate the response of surface water to the mandated sulfur emissions reductions.
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  • 14
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    Water, air & soil pollution 97 (1997), S. 205-207 
    ISSN: 1573-2932
    Keywords: mercury ; gold mining ; ecosystems ; methyl-Hg ; cycling ; global sources
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract As described by Jernelov and Ramel (1995), the Scientific Committee on Problems of the Environment (SCOPE) sponsored an investigation of Hg in ecosystems with special emphasis on tropical regions. In these regions small-scale gold mining activities have occupied about 10 million people worldwide who use Hg for extracting gold.
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  • 15
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    Water, air & soil pollution 97 (1997), S. 257-263 
    ISSN: 1573-2932
    Keywords: mercury ; atmosphere ; rainwater ; marine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Total gaseous mercury (TGM) and rainwater were collected on board of two research vessels (F. S. ALKOR and R.V. BELGICA) positioned 200 km apart in the center of the North Sea Experiment, September 1991. On the F.S. ALKOR (up-wind ship) TGM concentrations ranged from 0.7 to 2.6 ng·m-3 with an average of 1.5 ng·m-3 and on the R. V. BELGICA (down-wind ship) TGM ranged from 0.7 to 1.9 ng·m-3 with an average of 1.2 ng·m-3. An average 20% decrease is observed from the up-wind to the downwind ship, which may largely be affected by entrainment into the free troposphere. An overall removal was 0.5 cm·s-1 for dry periods and varied between 1 to 5 cm·s-1 during rain events. Rainwater concentrations varied between 5 and 25 ng·l-1. Based on these data an annual wet deposition flux of 1.08 ng Hg cm-2 yr1- was estimated for the North Sea.
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  • 16
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    Water, air & soil pollution 97 (1997), S. 205-207 
    ISSN: 1573-2932
    Keywords: mercury ; gold mining ; ecosystems ; methyl-Hg ; cycling ; global sources
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract As described by Jemelov and Ramel (1995), the Scientific Committee on Problems of the Environment (SCOPE) sponsored an investigation of Hg in ecosystems with special emphasis on tropical regions. In these regions small-scale gold mining activities have occupied about 10 million people worldwide who use Hg for extracting gold.
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  • 17
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    Water, air & soil pollution 97 (1997), S. 257-263 
    ISSN: 1573-2932
    Keywords: mercury ; atmosphere ; rainwater ; marine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Total gaseous mercury (TGM) and rainwater were collected on board of two research vessels (F. S. ALKOR and R.V. BELGICA) positioned 200 km apart in the center of the North Sea during the North Sea Experiment, September 1991. On the F. S. ALKOR (up-wind ship) TGM concentrations ranged from 0.7 to 2.6 ng·m−3 with an average of 1.5 ng m−3 and on the R. V. BELGICA (down-wind ship) TGM ranged from 0.7 to 1.9 ng·m−3 with an average of 1.2 ng·m−3. An average 20% decrease is observed from the up-wind to the down wind ship. which may largely be affected by entrainment into the free troposphere. An overall removal (entrainment) velocity of 0.95 cm·s−1 was calculated for the whole experiment. The average removal velocity was 0.5 cm·s−1 for dry periods and varied between 1 to 5 cm·s−1 during rain events. Rainwater concentrations varied between 5 and 25 ng·1−1. Based on these data an annual wet deposition flux of 1.08 ng Hg cm−2 yr1− was estimated for the North Sea.
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  • 18
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    Water, air & soil pollution 98 (1997), S. 241-254 
    ISSN: 1573-2932
    Keywords: coal ; deposition ; emission ; mercury ; municipal solidwaste
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Different species of mercury have different physical/chemical properties and thus behave quite differently in air pollution control equipment and in the atmosphere. In general, emissions of mercury from coal combustion sources are approximately 20–50% elemental mercury (Hg°) and 50–80% divalent mercury (Hg(II)), which may be predominantly HgCl2. Emissions of mercury from waste incinerators are approximately 10–20% Hg° and 75–85% Hg(II). The partitioning of mercury in flue gas between the elemental and divalent forms may be dependent on the concentration of particulate carbon, HCl and other pollutants in the stack emissions. The emission of mercury from combustion facilities depends on the species in the exhaust stream and the type of air pollution control equipment used at the source. Air pollution control equipment for mercury removal at combustion facilities includes activated carbon injection, sodium sulfide injection and wet lime/limestone flue gas desulfurization. While Hg(II) is water-soluble and may be removed from the atmosphere by wet and dry deposition close to combustion sources, the combination of a high vapor pressure and low water-solubility facilitate the long-range transport of Hg° in the atmosphere. Background mercury in the atmosphere is predominantly Hg°. Elemental mercury is eventually removed from the atmosphere by dry deposition onto surfaces and by wet deposition after oxidation to water- soluble, divalent mercury.
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  • 19
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    Water, air & soil pollution 98 (1997), S. 389-399 
    ISSN: 1573-2932
    Keywords: fertilizer ; nitrogen ; pollution ; runoff ; stable isotopes ; sugarcane
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract In many forested wetlands of Louisiana, surface water quality is being deteriorated by nutrient input from adjacent agricultural production areas. This field study assesses the input of fertilizer N, applied to sugarcane fields, to forested wetlands. The potential use of natural abundance variations in 15N14N ratios for identification and tracing surface water N sources (NH 4 + - and NO3 --N) was evaluated. Runoff and surface water samples were collected from sugarcane fields and bordering forested wetlands (6 stations) over a 16 month period and analyzed for NH 4 + -N, NO 3 - -N, and associated NH 4 + -δ15N and NO 3 - -δ15N ratios. Fertilizer N draining into adjacent forested wetland was estimated to be only a small fraction of the amount applied. Concentrations of NH 4 + - and NO 3 - -N in the collected water samples were low and ranged from 0.02 to 1.79 mg L-1. Isotopic analysis revealed NH 4 + -δ15N and NO 3 - -δ15N means were distinctive and may have the potential to be used as tracers of N contamination. The mean NH 4 + -δ15N value was +18.6 ± 7.1‰ and the NO 3 - -δ15N mean was +8.3 ± 3.1‰. Anomalously high NO 3 - -δ15N values (〉30‰) were attributed to denitrification.
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  • 20
    ISSN: 1573-2932
    Keywords: Biomass ; calcium ; fertilization ; loss ; magnesium ; nitrogen ; nutrient ; potassium ; recovery ; soil
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract The distribution of nutrients between soil layers and above-ground tree components was examined in a Norway spruce stand that had received ammonium nitrate (annually) and superphosphate (about every third year) for 22 years. Four treatments were included in the study; control (n = 4), N1P1, N2P2 and N3P2 (n = 2), which had received a total of 0, 730, 1700 and 2550 kg nitrogen (N) ha-1, 0, 130, 300 and 300 kg phosphorus (P) ha-1 and 0, 340, 784 and 784 kg calcium (Ca) ha-1, respectively. Compared with the control, stem-wood growth had been three times higher in N1P1 and three and a half times higher in N2P2 and N3P2. Amounts of N, P, Ca, potassium (K) and magnesium (Mg) in the above-ground tree biomass increased (p〈0.05) with the fertilizer dose, whereas manganese (Mn) did not. The recovery of fertilizer N and Ca in soil and above-ground tree biomass was negatively related to the fertilizer dose, although there had been a buildup of the N and Ca pools in the mor layer. This strongly indicates that at least the higher doses of N addition caused substantial nitrate leaching. Soil pools of K, Mg and Mn decreased as the fertilizer dose increased. However, the system total amounts (above-ground tree biomass plus soil) of K and Mg did not differ between treatments suggesting that no extra losses of these ions induced by nitrate leaching have occurred. Thus, in an aggrading forest ecosystem, N additions are likely to be followed by increased uptake of K, Mg and Ca. This may to some extent prevent extra leaching of these ions, which otherwise would be expected when there is an increase in nitrate leaching.
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  • 21
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    Water, air & soil pollution 99 (1997), S. 315-323 
    ISSN: 1573-2932
    Keywords: lake ; sediment ; carbon ; nitrogen ; stable isotope ; fractionation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Stable isotope composition of carbon and nitrogen in the sediment and pore water of a eutrophic freshwater lake was studied. Based on changes in the δ13C and δ15N values of dissolved components and sediment fraction, possible processes involved in the decomposition of sedimentary organic matter are outlined. The relative importance of acetate fermentation and CO2 reduction was estimated using known mathematical models, and ammonia assimilation by methanogenic bacteria is hypothesised to be the main process governing the isotope fractionation of dissolved nitrogen in pore water.
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  • 22
    ISSN: 1573-2932
    Keywords: Adriatic Sea ; nutrients ; benthic fluxes ; carbon ; nitrogen ; silicon ; phosphorus ; budgets
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Benthic fluxes of dissolved inorganic N, Si and P nutrients, alkalinity, dissolved inorganic C (DIC), and O2 from sediments in the Gulf of Trieste (northern Adriatic, Italy) were measured monthly in the period September 1995 - August 1996 using in situ incubated light benthic chambers. The highest efluxes of DIC, NH4+, PO43-, Si(OH)4, and NO3- influxes encountered in late summer - early autumn were the consequence of degradation of benthic microalgae, and in autumn mostly of sedimented phytoplankton. High NO3- efflux was observed in spring. Only NH4+ and Si(OH)4 fluxes were significantly correlated with temperature. This correlation suggests that the rate of downward input and the quality and quantity of sedimentary organic matter (autochthonous and allochthonous) were superimposed on the temperature fluctuations. High DIC, NH4+ and Si(OH)4 effluxes observed in July 1996 were due to the late spring - early summer degradation of sedimentary organic matter produced by benthic microalgae, while the autumn phytoplankton bloom was quickly reflected in enhanced benthic fluxes due to higher temperature. Significant correlations between NH4+, PO43- and Si(OH)4 fluxes suggested their parallel regeneration and utilization at the sediment-water interface. The nutrient fluxes were linked to O2 consumption, suggesting that aerobic oxidation processes were important at the sediment-water interface in the Gulf. The N, P and Si nutrients released from sediment pore waters are probably utilized in benthic microalgal and bottom-water primary production. This indicates that pelagic and benthic communities in the central part of the Gulf of Trieste function relatively independently of each other.
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  • 23
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    Water, air & soil pollution 99 (1997), S. 477-486 
    ISSN: 1573-2932
    Keywords: sediment ; nitrogen ; phosphorus ; organic matter ; cluster analysis ; Gulf of Finland ; estuaries
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Dry weight (DW), ignition loss (IL) and concentrations of total nitrogen (TN) and total phosphorus (TP) of the sediment surface layer (0 to 10 cm, 1 cm slices) were analyzed from 20 sites in the eastern Gulf of Finland. The distance of the sampling sites from the mouth of the River Neva explained the nutrient concentrations of the sediments well, while the effect of water depth was negligible. The increase of TN and the decrease of TP along the transect from the river mouth towards the open Gulf were caused by the diminishing share of allochthonous material supplied from the River Neva. The mean TN concentration of the different accumulation areas was about 40 % higher in the sediment surface than in the deeper layer (9 to 10 cm). The corresponding difference for TP varied from 53 to 56 %. The results suggest considerable netflux of nutrients from sediment to water. The net sediment accumulation of nutrients were estimated as 6.0 g m-2 a-1 of N and 1.7 g m-2 a-1 of P corresponding 22 000 t a-1 of N and 6 100 t a-1 of P for the whole eastern Gulf.
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  • 24
    ISSN: 1573-2932
    Keywords: nitrogen ; acidification ; Adirondack Mountains ; atmospheric deposition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Assessments of the aquatic effects of acidic deposition have focused on sulfur, as have recent efforts to control the emissions of acidifying compounds. Nitrogen dynamics were excluded from most acidic deposition modeling studies because it was believed that terrestrial ecosystems strongly retain N and because modeling N is a more formidable task than modeling S due to the influence of complex biological processes on N cycling. Re-examination of available data for the Adirondack Mountains of New York suggests that N deposition may be contributing to both chronic and episodic acidification of freshwaters to a greater extent than is generally believed. Previous research concluded that N has played a limited role in acidification processes in these lakes, based on regional averages of chronic chemistry. However, it is now known that historic acidification responses have been spatially variable within the Adirondack Mountains and that the declines in lakewater pH have been less than previously believed. Lakewater NO3 - concentrations are commonly in the range of 5 to 25 μeq L-1 on a chronic basis in portions of the Adirondack region that have experienced significant chronic acidification. These NO3 - concentrations correspond in magnitude to inferred historical acidification. Furthermore, the relative importance of NO3 - as an agent of acidification increases dramatically during snowmelt when conditions are most toxic to fish. The consequence of not addressing N in formulating acidification recovery strategies for the Adirondacks includes the likelihood that we will overestimate the response of surface water to the mandated sulfur emissions reductions.
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    Environmental monitoring and assessment 48 (1997), S. 285-296 
    ISSN: 1573-2959
    Keywords: herring gulls ; heavy metals ; selenium ; feathers ; bioindicator ; mercury ; lead ; cadmium ; chromium ; manganese
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract With increasing interest in assessing the health or well-being ofcommunities and ecosystems, birds are being used asbioindicators. Coloniallynesting species breed mainly in coastal areas that are alsopreferred for humandevelopment, exposing the birds to various pollutants. Inthis paper concentrations of heavy metal and selenium in the feathers ofHerring Gulls(Larus argentatus) nesting in several colonies fromMassachusetts toDelaware are reported. There were significant differencesamong colonies forall metals, with metal concentrations being two to nearly fivetimes higher atsome colonies than others. Selenium showed the leastdifference, and cadmium showed the greatest difference among sites. Concentrations of lead werehighest at Prall‘s Island; mercury was highest at Shinnecock,Huckleberry andHarvey, and manganese was highest at Captree.
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  • 26
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    Environmental monitoring and assessment 47 (1997), S. 79-87 
    ISSN: 1573-2959
    Keywords: air emissions ; Canada ; mercury ; Ontario ; sources
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Mercury is released to the environment from various anthropogenic and natural sources. This work is a compilation of mercury emissions from anthropogenic sources in Ontario, Canada. The goal of our study was to identify all sources of mercury, and develop an emission inventory of anthropogenic mercury in Ontario. The result of our investigation revealed that combustion of fossil fuels and emissions from landfill sites are two primary sources of mercury to the atmosphere. Other sources of significance are emissions from waste incinerators, various industrial activities, and cement production. Total mercury emission in Ontario is estimated as 4100 kg per year.
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  • 27
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    Environmental monitoring and assessment 57 (1999), S. 85-107 
    ISSN: 1573-2959
    Keywords: Kissimmee River ; mercury ; nutrients ; restoration ; water quality
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract The planned restoration of the Kissimmee River ecocystem will backfill approximately 35 km of flood control canal (C-38) that cuts through the meandering river channel, re-establish natural flow patterns, and restore the river/floodplain ecosystem. Water quality monitoring, including nutrients, total suspended solids (TSS), turbidity, dissolved oxygen (DO), and mercury, was conducted during a pilot `test fill' project to determine if soil disturbance during canal backfilling would negatively impact these water quality constituents. Surface water nutrient concentrations varied little between sites. Generally, highest concentrations occurred prior to construction, with lowest concentrations occurring during and after construction. During construction, TSS concentrations increased at sites immediately upstream, downstream, and adjacent to the construction area. Increased turbidity was generally restricted to areas immediately upstream and downstream of the test plug, with maximum levels occurring during the initial construction phase. Some downstream increases in turbidity were observed; however, impacts were short-term, lasting less than 24 h. Depresssed DO levels (〈2 mg/l) were observed upstream of the test plug following completion of the initial plug across C-38. Dissolved oxygen levels remained low for approximately 6 weeks, with no apparent ecological impacts. Total mercury (HgT) within canal sediment ranged from 9.2–180 ng/g and methylmercury concentrations ranged from 0.037–0.708 ng/g. Concentration of total mercury and total methylmercury (MeHgT) in the backfill material were much lower than concentrations in the canal sediment. No significant change in aqueous HgT concentrations occurred over the sampling period, although construction-induced turbidity could have temporarily caused a slightly elevated concentration immediately downstream of the construction site. Methylmercury concentrations in the water column ranged from 0.033–0.518 ng/l. No significant differences in mean MeHgT concentrations occured between sites or between sampling dates, except at one downstream site where MeHgT declined significantly over the sampling period.
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  • 28
    ISSN: 1573-2959
    Keywords: bioaccumulation ; mercury ; methylmercury ; remediation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Approximately 250 000 kg of mercury was lost towater and soils at the U.S. Dept. of Energy Y-12 Plantin Oak Ridge, Tennessee in the 1950s and early 1960s. A creek originating within the plant receivedcontinuous inputs of waterborne mercury, predominantlyas dissolved inorganic mercury, from groundwater,streambed contamination, and sump and process waterdischarges to the contaminated storm sewer network.These produce aqueous total mercury concentrations of1–2 μg L-1 in the upper reaches of the stream,decreasing to about 0.1–0.2 μg L-1 in its lowerreaches. A program to reduce mercury concentrationsin the creek identified specific sources (buildingsumps, contaminated springwater seeps, foundationdrains, and contaminated piping) and rerouted wateraround contaminated portions of the drain system orcollected and treated mercury-contaminated waterbefore discharging it. As a result, waterbornemercury concentrations in the creek and total mercuryloading were reduced from 1.8 μg L-1 to0.6 μg L-1 and 100 to 20 g d-1, respectively, in the last 5 yr.Mean mercury concentrations in fish nearest sourceareas in the creek headwaters decreased at roughly thesame rate as waterborne total mercury concentrationsover the past five years, but at the facility boundarydownstream the decline in mercury bioaccumulation wasmuch less. At sites 5–15 km farther downstream, nodecrease was evident. Dissolved methylmercury tendedto increase with distance downstream in a patterninverse to that noted for its dissolved inorganicmercury precursor.Improvements in water quality and modification ofweirs to allow the passage of fish have resulted inthe establishment of large populations of fish inmercury-contaminated headwater areas previously devoidof fish. It may be that the accumulation, retention,and eventual downstream transport of this reservoir ofbiologically incorporated methylmercury has acted tobuffer against expected reductions in mercury in fishat downstream sites.
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  • 29
    ISSN: 1573-3017
    Keywords: mercury ; small mammals ; bioaccumulation ; tissue residues ; toxicity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Mercury concentrations were determined in surface soil and biota at a contaminated terrestrial field site and were used to calculate transfer coefficients of mercury through various compartments of the ecosystem based on trophic relationships. Mercury concentrations in all compartments (soil, vegetation, invertebrates, and small mammals) were higher than mercury concentrations in corresponding samples at local reference sites. Nonetheless, mercury concentrations in biota did not exceed concentrations in the contaminated surface soil, which averaged 269 μg g-1. Plant tissue concentrations of mercury were low (0.01 to 2.0 μg g-1) and yielded soil to plant transfer coefficients ranging from 3.7×10-5 for seeds to 7.0×10-3 for grass blades. Mercury concentrations in invertebrates ranged from 0.79 for harvestmen (Phalangida) to 15.5 μg g-1 for undepurated earthworms (Oligochaeta). Mean food chain transfer coefficients for invertebrates were 0.88 for herbivores/omnivores and 2.35 for carnivores. Mean mercury concentrations in target tissue (kidney) were 1.16±1.16 μg g-1 for the white-footed mouse (Peromyscus leucopus), a granivore, and 38.8±24.6 μg g-1 for the shorttail shrew (Blarina brevicauda), an insectivore. Transfer coefficients for diet to kidney were 0.75 and 4.40 for P. leucopus and B. brevicauda, respectively. A comparison of kidney mercury residues measured in this study with values from controlled laboratory feeding studies from the literature indicate that B. brevicauda but not P. leucopus may be ingesting mercury at levels that are nephrotoxic.
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  • 30
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    Water, air & soil pollution 101 (1998), S. 289-308 
    ISSN: 1573-2932
    Keywords: emission factor ; emissions ; inventory ; mercury ; operating rate ; sources ; uncertainty
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Estimates of mercury emissions from individual sources and source categories are needed to understand relationships between the emissions and resulting deposition and to evaluate possible approaches to reducing those emissions. We have developed geographically-resolved estimates of annual average mercury emission rates from current anthropogenic sources in the 48 contiguous United States. These estimates were made by applying emission factors to individual facility operating data and to county-wide source activity levels. We apportioned the emissions to an Eulerian modeling grid system using point source coordinates and the fractions of county areas in each grid cell. Point sources account for about 89% of the 48-state total mercury emissions of 146.4 Mg/yr. Most of the emissions in the inventory are from combustion of mercury-containing fossil fuels and municipal waste, located primarily in the mid-Atlantic and Great Lakes states as well as in the Southeast. The major uncertainties in the emission estimates are caused by uncertainties in the emission factors used to develop the estimates. This uncertainty is likely a result of variability in the mercury content of the combusted materials and in the removal of mercury by air pollution control devices. The greatest research need to reduce uncertainties in mercury emission estimates is additional measurements to improve emission factors.
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    Water, air & soil pollution 102 (1998), S. 37-60 
    ISSN: 1573-2932
    Keywords: behavior ; distribution ; Nakdong River ; nitrogen ; phosphorus ; spatial ; temporal
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract The concentrations of nitrogen (N) and phosphorous (P) species and relevant hydrographic parameters were determined in main stream and tributary waters of the Nakdong River system during the periods of May through October 1994. During the entire period, the total N (TN) and total P (TP) concentrations in surface waters were found within the ranges of 0.4–7.0 (N=241) and 0.02–1.536 mg L-1 (N=241), respectively. To help derive meaningful interpretations of temporal and geographical variabilities in the nutrient bahavior, the entire data were evaluated for each individual parameter after employing several different grouping schemes. The results of this comparative analysis can be expressed in terms of: (1) high summer/fall ratios for most of nutrient species; and (2) low summer/fall ratios for most of nutrient-to-nutrient ratios and relevant hydrographic parameters. Interestingly, while the former case was found to be more significant in tributary waters than main stream waters, such geographical dependence was not strongly evident for the latter case. A z-statistic test, conducted to check the significance of temporal (between summer and fall) and spatial (between tributary and main stream regions) differences, confirm that the observed variabilities are in most cases strong enough for most of variables studied – nutrient species, their ratios, and relevant hydrographic parameters. In addition, comparison of nutrient species between dissolved and particulate phases reveals several interesting features. Unlike dissolved nutrient species, the concentrations of particulate N or P (PN or PP) exhibited quite extraoridanry behavior. While PN appears to be rather minor component of the total N budget for the Nakdong river, PP seems to make rather strong contributions to its total P budgets with its strong input from tributary waters during rainy summer season. Through an application of correlation analysis, relationships between different parameters were investigated for both before and after the grouping of data sets. The overall picture of this analysis showed that nutrient species were strongly correlated with each other, while the strongest correlations were among such hydrographic parameters as DO, BOD, COD, and conductivity. This analysis was further conducted to more deliberately divided data groups. The results of analyses on these sub-grouped data sets indicate that the occurrences of significant corelations were common from tributary waters relative to main streams for both (1) between different nutrient species and (2) between nutrient and hydrographic parameters. Using the line of evidence gathered from the statistical tests and from the correlation analysis, we conclude that the environmental health of the Nakdong river system is affected by the combined effects of various factors and processes.
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  • 32
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    Water, air & soil pollution 102 (1998), S. 427-436 
    ISSN: 1573-2932
    Keywords: chlor-alkali plant ; Hypogymnia physodes ; lichens ; mercury
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Emissions of mercury from a chlor-alkali plant in central Wisconsin have raised concern about possible effects on biota in the area. Samples of the lichen Hypogymnia physodes, which no longer grows in the area, were transplanted from a site in northeastern Wisconsin and positioned on plastic stands at varying distances up to 1250 m from the plant and sampled for Hg quarterly for one year to test the hypothesis that Hg would be taken up by the lichens and would decline with distance. Average tissue concentrations were elevated when first sampled at three months and continued to increase at the nearest sites until the study ended after one year. Average concentrations after a year of exposure ranged from 4418 ppb at 250 m from the plant to 403 ppb at 1250 m from the plant. The decrease over distance followed a negative exponential pattern. Background concentrations at a control site in northern Wisconsin averaged 155 ppb.
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  • 33
    ISSN: 1573-2932
    Keywords: aquatic ; Clear Lake ; mercury ; mining ; pollution ; sediments ; water
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Mining operations conducted at the Sulphur Bank Mercury Mine at Clear Lake, California, from 1872–1957, together with acid mine drainage since abandonment, deposited ca. 100 metric tons of mercury (Hg) in the sediments of Clear Lake. In 1992 Hg in surficial sediments (up to 183 mg kg-1 total Hg and 15.9 μg kg-1 methyl Hg) exhibited a classic point source distribution with maximum concentrations adjacent to the mine. However, the ratio of methyl:total Hg in sediments increased with distance from the mine, suggesting either differential transport of methyl Hg or a non-linear relationship between sediment inorganic Hg concentrations and methylation. Water exhibited an even more gradual decline in total Hg concentrations with distance from the mine, in both unfiltered bottom water (max. ca. 70 ng L-1) and filtered surface water (max. ca. 7 ng L-1). In comparison with other studies, Clear Lake exhibits high total Hg in sediment and water, yet relatively low methyl Hg concentrations. Our findings indicate a non-linearity between total and methyl Hg concentrations in sediments. The ratio of methyl:inorganic Hg is approximately 2 orders of magnitude higher in the water column than in the sediments, making the methyl fraction much more available for down-gradient transport away from the mine. Particulate Hg comprises ca. 33–94% of the total Hg and ca. 25–78% of the methyl Hg in the water column. Geothermal springs do not appear to represent a significant source of Hg to Clear Lake. The present pattern of Hg distribution in Clear Lake shows that water column transport plays some role in the lake-wide contamination of methyl Hg, but high methylation at relatively low inorganic Hg concentrations cannot be ruled out. No quantitative estimate of the area of sediments requiring remediation is possible from these descriptive data alone.
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  • 34
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    Water, air & soil pollution 107 (1998), S. 277-288 
    ISSN: 1573-2932
    Keywords: freezing ; lyophilisation ; mercury ; methylmercury ; sediment
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Estuarine and riverine sediments from fourlocations showing different sediment structures wereanalysed as fresh, thawed and lyophilised samples fortotal mercury (TotHg) and methylmercury (MeHg)concentrations, and results were compared to addresseffects of sample preservation on Hg speciation. TotHg was measured by cold vapour atomic absorptionspectrometry (CVAAS). MeHg was isolated bydistillation and ion-exchange and analysed by coldvapour atomic fluorescence spectrometry (CVAFS) afterpreconcentration on a gold trap. No loss of TotHg norMeHg due to lyophilisation was found. Concentrationsof TotHg and MeHg respectively ranged from 92 to 267ng g-1 dw and 1.1 to 2.9 ng g-1 dw in freshsamples, from 94 to 215 ng g-1 dw and 1.1 to 2.8ng g-1 dw in thawed samples, and from 100 to 256ng g-1 dw and 1.2 to 3.1 ng g-1 dw inlyophilised samples. Lyophilised samples showedbetter homogeneity and better MeHg analysisreproducibility compared with wet samples.
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  • 35
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    Water, air & soil pollution 111 (1999), S. 337-357 
    ISSN: 1573-2932
    Keywords: mass balance model ; mercury ; temperature lake
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract A simple, mechanistic model of mercury (Hg) dynamics in a lake has been developed, based on the fugacity/aquivalence approach of Mackay (1991) and Mackay and Diamond (1989) and its extension to treat several interconverting chemical species (Diamond et al., 1992). The model considers the distribution of inorganic (HgII), elemental (Hg°) and methyl (MeHg) mercury species between dissolved and particle-sorbed phases, and fate and transport in a system consisting of a well-mixed water column and an active sediment layer. Hg can enter the lake from watershed runoff and by atmospheric deposition directly to the lake surface. Once in the lake, Hg exchanges between water and air, and water and sediments, and exits by sediment burial, advective flow and volatilization. The model was applied to a hypothetical drainage lake on the Canadian Shield. Model estimates of water and sediment concentrations compare well with measured values. The results suggest that the three Hg species experience significantly different fates and persistence, with overall Hg dynamics dominated by the fate of HgII (the predominant species). A sensitivity analysis illustrates the importance of physical/chemical properties and lake characteristics on the total amount and behavior of Hg in the lake.
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  • 36
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    Water, air & soil pollution 112 (1999), S. 259-278 
    ISSN: 1573-2932
    Keywords: forest ; municipal sludge ; nitrogen ; soil
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Nitrogen dynamics were assessed for a forested site in southern New Hampshire during the first and second growing seasons after surface application of an aerobically-digested, limed, liquid municipal sludge. Sludge was applied in June 1989, at 3.3, 6.9, and 14.5 M ha-1 (or 199, 396, and 740 kg TKN ha-1). Elevated net N mineralization (in situ buried bags) occurred in the organic and upper mineral soil horizons during the first two months after sludge application, but was similar to control levels thereafter. Net N mineralization was negligible at 30 and 60 cm soil depths. Foliar N concentration increased with sludge loading rates. Concentrations of NH4+ and NO3- in soil leachate were low, except in early fall when microbial activity was still high and plant demand was low. In trenched subplots where vegetative uptake was eliminated, NO3- concentrations in soil leachate (60 cm) rose to between 15 and 35 mg N L-1 in the first year and remained high in the second year. Other studies reported higher magnitudes of NO3- leaching from treated plots. These studies and the findings reported here shown the characteristics of the sludge being applied to land are at least as important as the physical and chemical characteristics of the site to which they are to be applied.
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    Water, air & soil pollution 116 (1999), S. 135-140 
    ISSN: 1573-2932
    Keywords: mycorrhiza ; Pinus sylvestris ; nitrogen ; diversity ; mycorrhizal frequency
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract In the last three decades high industrial nitrogen (N) emissions have led to eutrophication of a Scots pine stand (Pinus sylvestris [L.]) near Schwedt characterized by a broad cover of Calamagrostis epigejos [L.] Roth (Poaceae). In comparison to the relatively unimpacted control site (low N site), this high N site showed a remarkably low mycorrhizal frequency (percentage of mycorrhizas on total amount of root tips) with seasonal lows down to 27 %. At the low N site the highest number of mycorrhizal root tips was found in the organic layer. At the high N site the amount of mycorrhizas per soil volume was similar in both organic and mineral soil layers, and also significantly lower when compared to the amount at the low N site. The high N site revealed only nine mycorrhizal morphotypes instead of eighteen found at each sampling date at the control site. 80 % of the coenosis at the high N site were represented by only four morphotypes resulting in a low diversity. The seasonal decrease in the mycorrhizal frequency, the small amount of mycorrhizas and the low diversity suggest that the high N deposition at this site has reduced the ability of the pine trees to withstand natural stresses such as prolonged drought or frost periods. This corresponds well with the 42 % reduction in tree stocking density at the high N site compared to the low N site.
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  • 38
    ISSN: 1573-2932
    Keywords: groundwater ; nitrogen ; sandy soils
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Application of soluble forms of nitrogen (N) fertilizers to citrus trees in sandy soils of central Florida may cause leaching of NO 3 − below the rooting depth. A leaching column study was conducted to evaluate the leaching of urea, NH 4 + and NO3 − forms of N from calcium nitrate, urea, and urease inhibitor coated urea (Agrotain: N-(-n butyl) thiophosphoric triamide (NBPT)) applied to a Candler fine sand (hyperthermic, uncoated Typic Quartzipsamments) during six cycles of intermittent leaching with 220 mL each of water (total 1320 mL) through the soil columns (equivalent to 30 cm rainfall). The amount of NO3-N recovered in the leachate from calcium nitrate treated soil accounted for 43% of the total N applied. Leaching of N from urea and Agrotain treated soil was pronounced during the second and third leaching events. Cumulative leaching of urea form of N accounted for 12 and 8% of total N applied as urea and Agrotain, respectively. The cumulative amounts of NO3-N and NH4-N recovered in six leachate fractions from urea treated soil accounted for 14 and 21%, respectively, of the total N applied to the column. The corresponding values for the Agrotain treated soil were 8 and 17%, respectively. Soil analysis after the completion of leaching showed no urea throughout the entire depth of column in either urea or Agrotain treatments. The total recovery of N (leachate plus soil) was 48.1, 40.4, and 49.7% of total N applied as urea, Agrotain, and calcium nitrate, respectively. This study demonstrated a significant reduction in leaching of N forms from Agrotain as compared with that from urea.
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  • 39
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    Water, air & soil pollution 102 (1998), S. 361-375 
    ISSN: 1573-2932
    Keywords: alternative on-site wastewatertreatment and disposal systems ; fill material ; low pressuredistribution systems ; minespoil ; nitrogen ; phosphorus ; wastewater renovation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Development of Appalachian coal mining regions of the USA has been severely hampered by lack of domestic waste disposal technologies suited to fills. The suitability of on-site wastewater treatment and disposal systems (OSWTDS) in fill material is uncertain due to the effects of surface mining on soil physical properties. This research was conducted to evaluate the potential for renovation of N and P present in domestic wastewater by fills produced from mining operations. Nitrogen and P were chosen because of their potential adverse environmental impacts. Soil-fill (a mixture of Jefferson, fine-loamy, siliceous, mesic Typic Hapludult and Muskingom, fine-loamy, mixed, mesic Typic Dystrochrept soils) and minespoil (spoil)-fill (blasted rock material associated with the Taggart Marker and Low Splint Bench coal seams of the Upper Middle Wise Formation) were used in this study. Septic tank effluent (STE) and sand filter effluent (SFE) were applied to spoil-fill columns at four loading rates (0, 5.4, 10.8, and 21.6 L m-2d-1) and spoil-fill columns at one loading rate (21.6 L m-2d-1) for a period of 20 wk. Renovation of wastewater was assessed by determining the concentration of N and P present in column leachate. Reduction of inorganic N (NO3 - + NH4 +), based on N/Cl ratios, ranged from 14.9 to 32.1% after the varying application rates of STE and SFE passed through the soil columns. However, leachate NO3 --N concentrations were still above the 10 mg-1 drinking water standard. The quantity of P emerging from the spoil-fill columns (3.0 mg P L-1) was higher than anticipated and may be related to the indigenous P present in the minespoil. Sorption of P in the soil-fill column decreased with increased STE and SFE application (reductions ranged from 99.1 to 74.4%). Results from this study indicate that there is potential for renovating wastewater in OSWTDS in selected soil-fill areas in reclaimed minelands.
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  • 40
    ISSN: 1573-2932
    Keywords: fish ; French Guiana ; mercury ; stream
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract This study examines the level of mercury contamination for different components of the biosphere in French Guiana. The spatial variability of the contamination of the waters, soils and sediments in the catchment area of the Sinnamary River is studied. The contamination of the trophic chain isdiscussed by analysis of the flesh of fish for the principal species represented in nine Guianese rivers, especially species consumed by human populations. The mercury contamination of sediments and soils, is extremely heterogeneous and that of fish is generalised. For carnivorous fish, the average mercury content is 0.48 μg g-1 (±0.28) (fresh weight) and for non-carnivorous species, 0.05 μg g-1 (±0.07). The concentrationsmeasured are greater than the European standards forconsumption for 4.7% of the carnivorous individuals.
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  • 41
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    Water, air & soil pollution 105 (1998), S. 239-250 
    ISSN: 1573-2932
    Keywords: Finland ; forested catchments ; iron ; leaching ; nitrogen ; nutrients ; organic carbon ; peatland ; phosphorus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract This study provides an assessment of the spatial variability of the long-term leaching of nutrients, total organic carbon (TOC) and iron (Fetot) from 22 forested catchments (0.69-56 km2), distributed across all but the northenmost areas of Finland. The natural, unmanaged Kruunuoja catchment is located in a national park, while the other catchments represent Finnish forestry land. The average leaching of Ptot (4.2 kg km-2 yr-1) from the Kruunuoja catchment was small compared to the catchments representing forestry land (on average 10 kg km-2 yr-1). Moreover, P fertilization was the most important predictor for the spatial variation in Ptot leaching (r2=0.45). Leaching of TOC, Fetot and N compounds was not closely related to forestry practices. Median C/N ratio in the study streams was high (range 34-66). The average inorganic N proportion and leaching of Ptot were lowest in the Kruunuoja catchment (7.3 % and 2.8 kg km-2 yr-1, respectively) and highest in the southernmost Teeressuonoja catchment (54 % and 100 kg km-2 yr-1, respectively) located in the highest N deposition area. The most important forestry practices since the 1960's have affected about 2.4 % of the area of study sites per year (cf. 2% in the entire country in 1991). Moreover, the mean annual runoff from the catchments (230-430 mm yr-1) agrees with the mean annual runoff from Finland (301 mm yr-1). Consequently, the results of the study catchments can be used to estimate average total annual leaching from Finnish forestry land: 2,700 t of Ptot, 48,000 t of Ntot, 110,000 t of Fetot and 1.5 million t of TOC.
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  • 42
    ISSN: 1573-2932
    Keywords: acidic deposition ; Adirondack mountains ; disturbance ; modeling ; nitrogen ; sulfur
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Interactions between acidic deposition and watershed characteristics were evaluated for a group of lakes in the Adirondack Mountains, New York. Landscape characteristics were compiled and examined relative to paleolimnological inferences of historical acidification. Results of estimates of acidification using the Model of Acidification of Groundwater in Catchments (MAGIC) and paleolimnological analysis were compared to physical, biological, and landscape change data, including such factors as watershed disturbance, logging, fire, and windthrow, to evaluate if inclusion of additional processes could improve model estimates. Results of bivariate and multivariate analysis confirmed that lakes that have experienced historical acidification tend to be those that receive relatively high amounts of precipitation and have short hydraulic residence times. These variables explained 58% of the diatom-inferred acidification. A combined model of long-term precipitation amount, hydraulic residence time, and recent blowdown accounted for 71% of the historic acidification in the Adirondacks. Lakes that have increased in pH since pre-industrial times tend to be those subject to substantial human disturbance and those that burned during major fires recorded after 1900. The magnitude of the discrepancy between MAGIC model and diatom-inferred hindcasts of acidification was not significantly correlated with any of the landscape change variables, suggesting that additional modifications to the MAGIC model to take into account landscape change are not likely to appreciably improve model performance.
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  • 43
    ISSN: 1573-2932
    Keywords: bioaccumulation ; mercury ; methyl mercury ; tropic levels ; trout
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Methyl mercury (Hg) was determined in rainbow trout (Oncorhynchus mykiss) and organisms in the lower tropic levels: smelts (Retropinna retropinna), bullies (Gobiomorphus cotidianus), koura (Paranephrops planifrons); and zooplankton (Daphnia carinata and Calamoecia lucasi) in Lakes Okareka, Okaro, Tarawera, Rotorua and Rotomahana, New Zealand. Water concentrations of total Hg (HgT) and methyl Hg were also measured. Mean methyl Hg concentrations in the trout, the prey species (smelts, bullies and koura) and zooplankton increased linearly with mean HgT and methyl Hg chloride (CH3HgCl) concentrations in water. Most of the bio-magnification of methyl Hg occurred in the lower trophic levels of the trout food web (104.72) between the zooplankton and water. The bioaccumulation factors between the forage fish and zooplankton were 100.73 for bullies and 101.06 for smelt. Methyl Hg was 100.41 to 100.95 times greater in the trout then their prey.
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  • 44
    ISSN: 1573-2932
    Keywords: acidification ; emission ; MAGIC ; model ; nitrogen ; SAFE ; SMART ; sulfur
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Three well-known dynamic acidification models (MAGIC, SAFE, SMART) were applied to data sets from five Integrated Monitoring sites in Europe. The calibrated models were used in a policy-oriented framework to predict the long-term soil acidification of these background forest sites, given different scenarios of future deposition of S and N. Emphasis was put on deriving realistic site-specific scenarios for the model applications. The deposition was calculated with EMEP transfer matrices and official emissions for the target years 2000, 2005 and 2010. The alternatives for S deposition were current reduction plans and maximum feasible reductions. For N, the NOx and NHy depositions were frozen at the present level. For NOx, a reduction scenario of flat 30% reduction from present deposition also was utilized to demonstrate the possible effects of such a measure. The three models yielded generally consistent results. The ‘Best prediction’-scenario (including the effects of the second UN/ECE protocol for reductions of SO2 emissions and present level for NOx-emissions), resulted in many cases in a stabilization of soil acidification, although significant improvements were not always shown. With the exception of one site, the ‘Maximum Feasible Reductions’ scenario always resulted in significant improvements. Dynamic models are needed as a complement to steady-state techniques for estimating critical loads and assessing emission reduction policies, where adequate data are available.
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  • 45
    ISSN: 1573-2932
    Keywords: critical loads function ; emissions reductions ; modelling ; nitrogen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract It is now recognised that a multi-pollutant, multi-effect approach needsto be adopted to address the range of problems caused by atmosphericpollution. In this paper we use a relatively simple trajectory model (HARM)to explore the coupled behaviour of sulphur dioxide (SO2),oxides of nitrogen (NOx) and ammonia (NH3) andthe possible effects of future reductions in emissions of these pollutantson depositions of S and N across Great Britain. The performance of HARM withrespect to concentrations and depositions of NOy andNHx is assessed by comparison with data from nationalmonitoring networks. A range of emissions scenarios are modelled and theeffects of these reductions on critical loads exceedance are explored usingthe critical loads function (CLF), which allows both the acidification andeutrophication effects of S and N deposition to be explored simultaneously.Spatial variations in the reductions of deposition of S and/or N required tomeet critical loads are described. Reductions in emissions of the precursorsof strong acids (SO2 and NOx) yield benefits interms of ammonium deposition as a result of their coupled chemistry. Thedevelopment of strategies to control nitrogen deposition will need to take this non-linearity in to account.
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  • 46
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    Water, air & soil pollution 111 (1999), S. 287-295 
    ISSN: 1573-2932
    Keywords: analysis ; atomic fluorescence ; geological ; mercury ; water
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract The Tekran 2537A mercury vapour analyser, designed to measure Hg in air by cold vapour atomic fluorescence spectrometry, has been modified to determine Hg in solution. The new ‘front-end’, required to generate Hg° vapour from acidified waters or acid leachates, is described. Using 1% NaBH4 as reducing agent, a 12 mL water sample can be analysed, at a rate of 1 every 6 min, for Hg to a detection limit of 0.8 ppt (ng L-1). Instrumental precision is typically 1% relative standard deviation (RSD) at levels of Hg from 10 to 200 ppt. Results for 10 analyses of the international water standard, NIST 1642b, are 1530±20 ppt Hg, agreeing well with the certified value of 1480±130 ppt. Nineteen geological standard reference materials (soils, sediments and tills) were used to assess accuracy. Results for these samples, digested in aqua regia in triplicate, showed good agreement with recommended values for all but two, SO-3 and TILL-1. However, results by this method for these two standards were confirmed by an independent method, direct atomic absorption spectrometry. Average method precision was shown to be 5% RSD over the range 10 ng g- 1 to 35 μg g-1 Hg.
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  • 47
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    Water, air & soil pollution 112 (1999), S. 279-295 
    ISSN: 1573-2932
    Keywords: ambient air ; chemical analysis ; mercury ; particulatemercury ; speciation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Total particulate mercury (TPM) may constitute, in general, a small percentage by mass of total atmospheric mercury, but under certain conditions it can be a very significant form of atmospheric Hg, and play an important role in the deposition of mercury to terrestrial and aquatic cosystems. To understand the cycling and distribution of mercury in the environment, accurate determination of the total concentration and speciation of TPM are necessary. This article provides a review of scientific and technical literature published in the past 5 yr pertaining to sampling and analytical methodologies for the determination and chemical speciation of TPM in ambient air. Sampling methods discussed include the conventional filtration method and the diffusion denuder-based technique. Analytical techniques, such as gold-amalgamation/cold-vapor spectrometry, and nuclear methods, are summarized.
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  • 48
    ISSN: 1573-2932
    Keywords: Amazonia ; mercury ; soil erosion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Three Hg sources were characterised and mass balance calculations were used to determine their relative contributions to the contamination of the Amazonian environment. About an order of magnitude more Hg is emitted to the atmosphere by goldmining activity than by the burning of forest biomass. However, anthropogenic atmospheric Hg cannot account for the high Hg burdens found in terrestrial ecosystems: deposition of Hg from goldmining sources is estimated to account for less than 3% of the Hg present in the surface horizons of soils. We propose that erosion of deforested soils following human colonization constitutes a major disturbance of the natural Hg cycle. Deforestation thus increases soil Hg mobilisation by runoff, which may explain the increase of Hg burdens in Amazonian aquatic ecosystems in newly colonized watersheds.
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  • 49
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    Water, air & soil pollution 113 (1999), S. 141-154 
    ISSN: 1573-2932
    Keywords: forest soils ; mercury ; methylmercury ; runoff ; soil solution ; wetland
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Mercury (Hg) and methylmercury (CH3Hg+) are global pollutants, but little information is available on their distribution and mobility in soils and catchments of Central Europe. The objective of this study was to investigate the pools and mobility of Hg and CH3Hg+ in different forest soils. Upland and wetland forest soils, soil solutions and runoff were sampled. In upland soils the highest contents of total-Hg were found in the Oh layer of the forest floor (〉400 ng g-1) and the storage of non geogenic total-Hg (calculated for 60 cm depth) was about 120 mg/m2. The storage of total-Hg was one order of magnitude lower in wetland soils as compared to the upland soils. By far the largest proportion of total-Hg in soils was bound in immobile fractions. The depth gradients of CH3Hg+ did not correspond to those of total-Hg and the highest contents of CH3Hg+ in upland soils were observed in the litter layer of the forest floor and in the Bsv horizon. The CH3Hg+ content of the wetland soils was generally much higher in comparison with upland soils. CH3Hg+ in solution was found in the forest floor percolates of upland soils and in wetland soils, but not in soil solutions from mineral soil horizons. Gaseous losses of Hg as well as methylation of Hg are likely in wetland soils. The latter might be highly relevant for CH3Hg+ levels in runoff.
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  • 50
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    Water, air & soil pollution 113 (1999), S. 273-294 
    ISSN: 1573-2932
    Keywords: atmospheric deposition ; dissolved organic carbon ; mercury ; stemflow ; throughfall
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Inputs of mercury (Hg) and dissolved organic carbon (DOC) in throughfall and stemflow waters were measured for an upland/bog watershed in northern Minnesota, and were compared to the deposition in a nearby opening to determine the influence of tree canopies on Hg and DOC deposition. Twice as much Hg and seven times as much DOC was deposited in the forested watershed compared to the opening. Mass balance studies that are based on wet-only deposition in openings severely underestimate atmospheric deposition of Hg in forests. Conifer canopies are more efficient filters of airborne particulates than are deciduous canopies as indicated by much higher Hg concentrations and total deposition in throughfall and stemflow waters under conifers. Significant positive relationships existed between Hg and DOC in both throughfall (36–57% of the variation) and stemflow waters (55–88% of the variation). Hg complexation by DOC appears to be related to the contact time between precipitation and carbon sources.
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  • 51
    ISSN: 1573-2932
    Keywords: canopy resistance ; deposition ; emission ; micro-meterological approach ; nitrogen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract The present study aims to establish the annual NH3 deposition to an inland heathland in Denmark using a micro-meterological approach with passive wind-vane flux samplers. The integrating samplers were replaced at weekly intervals from May 1995 to May 1996. The average concentration, 2.05 μg m-3 at the heathland is at a moderate level when compared to heathlands in other parts of Europe. The average deposition velocity was 0.83 cm s-1 which is within the range of depositon velocities found for other heathlands in Europe. The average canopy resistance was found to be relatively high, 61 s -1. The measurements yielded a total NH3-N deposition of 2.4 (± 0.9) kg ha-1 yr-1 with a data coverage of 71% for 1995/1996. In 40% of this time the flux is regarded as zero because the flux is not significant different from zero. In 60% of this time the significant fluxes varied from –0.052 μg m-2 s-1 (deposition equal 16.4 kg N ha-1 yr-1) to 0.089 μg m-2 s-1 (emission equal 28.2 kg N ha-1 yr-1). The method is only able to direct measure significant fluxes down to the equivalence of 0.010 μg m-2 s-1 (approximately 3.2 kg ha-1 yr-1). Therefore the exact deposition cannot be determined by the applied method at very low deposition sites such as a coastal heathland in Denmark. In a high-deposition area as in the central Netherlands the method gave significant fluxes with a 100% data coverage for a two month period.
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  • 52
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    Water, air & soil pollution 114 (1999), S. 339-346 
    ISSN: 1573-2932
    Keywords: biomonitoring indices ; germination ; heavy metals ; lead ; mercury ; rice ; seedling growth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Treatment of seeds of two rice (Oryza sativa L.) cultivars (Ratna and IR36) separately with 10-5and 10-4M PbCl2and HgCl2decreased germination percentage, germination index (GI), shoot and root length, tolerance index (TI), vigour index (VI) and dry mass of shoot and root but increased percentage difference from control (% DFC) of germination and percentage phytotoxicity in both the cultivars. It was observed from these indices that the phytotoxic effect of mercury was greater than lead at identical concentrations and that IR36 appeared more tolerant than Ratna to these metals. Among the monitoring indices examined, TI, VI, and % phytotoxicity seemed to serve as good biological monitoring methods for evaluating the relative toxicity of lead and mercury to rice cultivars.
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  • 53
    ISSN: 1573-2932
    Keywords: eutrophication ; nitrogen ; phosphorus ; river ; sediment
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Nitrogen (N) and phosphorus (P) concentrations were determined in sediment samples along the bed of Catatumbo river in both Colombian and Venezuelan territories until the river outlet in Maracaibo lake. Total phosphorus was determined by digestion with HCl followed by analysis using the ascorbic acid method and total nitrogen was done using the standard microkjeldahl method plus nitrate-nitrite. Ammonium, orthophosphate and nitrate were determined using standard methods after extraction steps. The mean concentrations along the river bed were found in an interval of 0.035 and 1.492 mg g-1 dry sed. for nitrogen and 0.027 and 1.039 mg g-1 dry sed. for phosphorus at 95% confidence level. The mean molar ratio N/P in the river bed was 4.42 and 3.46 for river outlet zones in the lake, which indicates that nitrogen is the limiting nutrient. For comparison with previous results of lake sediments from sites near the river outlet it was concluded that Catatumbo river is a significant source of nutrients to the Maracaibo Lake system because sediment nutrients concentrations from Catatumbo river were higher than the ones in Maracaibo Lake. Statistic studies showed significant differences between countries, zones and similar behaviour in the river bed as related to the affluent rivers.
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  • 54
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    Water, air & soil pollution 117 (2000), S. 353-369 
    ISSN: 1573-2932
    Keywords: hydrogeochemistry ; Kejimkujik ; lake water quality ; mercury ; principal component analysis ; regression modeling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Distribution and sources of total mercury were evaluated in sixty lakes in Nova Scotia and Newfoundland. The concentration of total mercury in the lake water samples was similar to those observed in other natural water systems. Mercury concentration in the lakes correlated positively with aluminum, total organic carbon, color, iron, and total nitrogens and inversely with pH and sulfate. The lake water quality parameters were placed in three distinct groups using principal component and cluster analyses. The chemical constituents in the groups were identified as being associated with lake watershed geology, atmospheric washouts of long range transported acidic pollutants and dust particles, and a marine source. Stepwise multiple regression applied to the variables in the same principal component and strongly correlating with mercury identified total organic carbon, total nitrogen, pH, aluminum and iron as the best predictors for total mercury concentrations in the study lakes.
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  • 55
    ISSN: 1573-2932
    Keywords: mercury ; mercury fluxes ; solar radiation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Mercury flux measurements were conducted at two lakes and three soil sites in Kejimkujik National Park, located in the eastern Canadian province of Nova Scotia. One of the lakes had high levels of both mercury and Dissolved Organic Carbon (DOC). Two of the soil sites were located under the forestcanopy, while the other was in a small clearing surrounded by forest. Flux measurements were performed using the dynamic chamber method. Mercury concentrations in the air were measured with a TEKRAN mercury analyzer. Mercury fluxes over the two lakes were most strongly correlated with solar radiation, although the flux was also significantly correlated with water temperature, air temperature, and negatively correlated with relative humidity. The flux from the high DOC lake (Big Dam West) was especially high when the conditions were both sunny and windy (wind speed greater than 1.3 m s-1) and the average flux measured was 5.4 ng m-2 h-1. The mercury flux from this lake was wellparameterized in terms of a simple expression involving solar radiation and a nonlinear dependence on wind speed. The flux measured from the low DOC lake (North Cranberry) tended to be lower than from the high DOC lake. The averageflux measured was 1.1 ng m-2 h-1, but was again strongly correlated with solar radiation. The flux was low during windy conditions in the absence of sunlight, suggesting that wind enhances mercury evasion from lakes only in the presence of solar radiation. Mercury fluxes measured over the soil sites tended to be smaller than those over water (a range of –1.4–4.3 ng m-2 h-1). At one of the forest sites, mercury flux was very strongly correlated with 0.5 cm soil temperature, and this dependence was well described by an Arrhenius-typeexpression with an activation energy of 14.6 kcal-1 mole, quite close to the heat of vaporization of mercury (14.5 kcal-1 mol-1 at 20 °C). At the clearing, where there was direct exposure to the sun, the mercury flux was most strongly correlated with solar radiation.
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  • 56
    ISSN: 1573-2932
    Keywords: nitrification ; nitrogen ; nitrogen mineralization ; soil water ; stream chemistry ; wilderness area
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Nitrogen (N) deposition and its impact on terrestrial and aquatic ecosystems is a concern facing federal land managers at the Lye Brook Wilderness in Vermont and other protected aras throughout the northeastern United States. In this study, we compared N production in soils with N concentrations and outputs in leachates to determine how forest cover types differ in regulating N losses. Also, precipitation inputs and modeled estimates of streamwater outputs were used to calculate a watershed N budget. Most ammonium and nitrate were produced in organic soils with deciduous cover. Softwood stands had low net nitrification rates and minimal N leaching. A comparison of watershed inputs and outputs showed a net gain in total dissolved N (5.5 kg ha-1 yr-1) due to an accumulation of dissolved inorganic N. The Lye Brook Wilderness ecosystem has N budgets similar to other forested ecosystems in the region, and appears to be assimilating the accumulating N. However seasonal losses of nitrate observed in mineral soils and streamwater may be early warnings of the initial stages of N saturation.
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  • 57
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    Water, air & soil pollution 124 (2000), S. 301-317 
    ISSN: 1573-2932
    Keywords: fish ; lakes ; mercury ; model ; predictions ; regressions ; remedial measures
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract This work presents a new regression model for mercuryin lake fish, which provides the highest r 2-valueso far reported for a predictive model for Hg in lakefish. A new method to transform static regressionmodels to dynamic (time-dependent) models is alsopresented. The method to mathematically transformregression models to dynamic model uses the ecologicalhalflife concept and two differential equations, onefor the target organism (the predator) and one for theprey. This method is generic and can be applied inanalogous cases. The practical use of the dynamicmodel is illustrated in two case studies involvinglake liming and fertilization as methods to reduce Hgin lake fish. The dynamic model is a tool to obtainrealistic expectations of the recovery process, whichis slow because Hg in lake fish has a relatively longecological halflife (about 3 yr).
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  • 58
    ISSN: 1573-2932
    Keywords: denitrification ; nitrification ; nitrogen ; nitrous oxide ; wetlands ; 15 isotopes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract The transformations of applied (100 kg N ha-1)15 N labelled NO3 and NH4 in Mississippi River deltaic plain swamp forest soil which receives agriculture run-off from adjacent sugarcane fields were determined. Using an isotopic dilution technique, the rates of NO3 production (nitrification) and reduction in the 15NO3 treated soil-water-columns were approximately 240 and 2,320 g N ha-1 d-1, whereas NH4 production (mineralization) and removal rates in the 15NH4 treated soil-water-columns were 270 and 2160 g N ha-1 d-1, respectively. It was shown that if nitrification and NH4 assimilation were the primary processes responsible for NH4 removal, average NH4 assimilation would be 145 g N ha-1 d-1. Based on labelled N2-emission, denitrification was 3 fold greater in the NO3 treatment compared to the NH4 treated soil water-columns with rates of 818 and 266 g N ha-1 d-1 respectively. Even though the rate was lower in the NH4 treatment, results show that nitrification-denitrification of NH4 is a significant process. Nitrogen losses determined by15 N2 emissions were 20.4 and 6.4% and N2O emissions were 0.10 and 0.03% of the applied NO3-N and NH4-N, respectively, over 32 days of incubation. Fertilizer loss through N2O emission was only of minor significance compared to the fertilizer loss through N2 evolution. Nitrous oxide fluxes from the control soil-water-columns averaged 9.4 g N ha-1 d-1. Addition of NO3-N to the columns increased N2O production 56% as compared to a 15% increase from the NH4-N addition. Results show that this wetland soil has a large capacity to process inorganic nitrogen entering the system as a result of agriculture run-off.
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  • 59
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    Water, air & soil pollution 89 (1996), S. 267-275 
    ISSN: 1573-2932
    Keywords: mercury ; forest trees ; biomonitors ; contaminants
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract The concentration of mercury has been determined in assimilation organs of forest trees from 10 main industrial regions of Slovakia, four mountain forests and one military area and compared with concentration of mercury from 1356 permanent monitoring plots of Slovakia. The mercury concentration ranges for 2 yr old needles of Picea abies Karst. were (in mg kg−1): 1.249–4.402 (Rudnany iron ore mines), 0.013–0.749 (nine other industrial regions), 0.021–0.737 (four mountain forests) and 0.053–0.538 (military area). The mercury content in the soil (0–5 cm) from a mercury smelting plant ranged from 9.9 to 130 mg kg−1, and the moss Pleurozium schreberi contained 3.8–9.1 mg kg−1. The values obtained were compared with the available literature data.
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  • 60
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    Water, air & soil pollution 95 (1997), S. 35-43 
    ISSN: 1573-2932
    Keywords: humic acid ; mercury ; transport ; transformation ; soil-plant system
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract The influence of humic acid (HA) on the transport and transformation of mercury (Hg) in soil was studied. No available Hg could be detected (〈2.5 μg kg-1) in alluvial soil when the content of HA-carbon (HA-C) was higher than 0.2 g kg-1 although a large amount of Hg (8 μg kg-1) was applied to the soil. The available Hg decreased with the increase of HA in purple soil (r=0.735). There are significant correlations between HA concentration and organic Hg in the tested soils (r=0.974 for the purple soil and r=0.979 for the alluvial soil). The increase of HA results in decrease of Hg absorbed by plant from the soil. A loss of Hg from soil caused by microbes was observed.
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  • 61
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    Water, air & soil pollution 91 (1996), S. 33-42 
    ISSN: 1573-2932
    Keywords: lignite mining ; recultivation ; reafforestation ; mine soils ; fertilization ; nutrition ; nitrogen ; growth of trees and shrubs
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Based on numerous fertilization trials on mine soils of different physical and chemical properties in the Lusatian lignite mining district of northeastern Germany, optimized fertilization methods adapted to site and tree species are presented. Data for nutrition and growth of some tree species (Pinus sylvestris, Quercus rubra) are discussed.
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  • 62
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    Water, air & soil pollution 98 (1997), S. 241-254 
    ISSN: 1573-2932
    Keywords: coal ; deposition ; emission ; mercury ; municipal solid waste
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Different species of mercury have different physical/chemical properties and thus behave quite differently in air pollution control equipment and in the atmosphere. In general, emissions of mercury from coal combustion sources are approximately 20–50% elemental mercury (Hg°) and 50–80% divalent mercury (Hg(II)), which may be predominantly HgCl2. Emissions of mercury from waste incinerators are approximately 10–20% Hg° and 75–85% Hg(II). The partitioning of mercury in flue gas between the elemental and divalent forms may be dependent on the concentration of particulate carbon, HCl and other pollutants in the stack emissions. The emission of mercury from combustion facilities depends on the species in the exhaust stream and the type of air pollution control equipment used at the source. Air pollution control equipment for mercury removal at combustion facilities includes activated carbon injection, sodium sulfide infection and wet lime/limestone flue gas desulfurization. While Hg(II) is water-soluble and may be removed from the atmosphere by wet and dry deposition close to combustion sources, the combination of a high vapor pressure and low water-solubility facilitate the long-range transport of Hg° in the atmosphere. Background mercury in the atmosphere is predominantly Hg°. Elemental mercury is eventually removed from the atmosphere by dry deposition onto surfaces and by wet deposition after oxidation to water-soluble, divalent mercury.
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  • 63
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    Water, air & soil pollution 99 (1997), S. 217-223 
    ISSN: 1573-2932
    Keywords: selective leach ; organic ; humic ; fulvic ; analysis ; mercury ; zinc
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract The international reference lake sediment, LKSD-4, was used to compare Hg, organic C and Zn extracted from its 'soluble organic' phase by two commonly used reagents: 0.1 M Na4P2O7 solution at pH 10 and 0.5 M NaOH solution at pH 12. While recoveries of Hg and Zn by 0.1 M Na4P2O7 are not affected by changes in sample weight to reagent volume ratio (W/V) or contact time, those by NaOH show a marked dependency. In general, the NaOH leach extracts more organic C and Hg from LKSD-4 but less Zn. Over the range of conditions studied, the NaOH-based method extracted 4.7-9.8% C, 27-103 ng g-1 Hg and 19-69 µg g-1 Zn from LKSD-4, compared to 2.3-2.8% C, 17-24 ng g-1 Hg and 64-72 µg g-1 Zn by the Na4P2O7 leach. Clearly, different groups of organic substances are being dissolved by these two reagents and therefore a comparison of data from different laboratories becomes meaningless. This paper suggests that more research is needed into the exact nature of metal-organic associations extracted by selective leaches and into associated artifacts of extraction such as readsorption phenomena.
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  • 64
    ISSN: 1573-2932
    Keywords: Cystoseira myrica ; Red Sea ; coral reefs ; nitrogen ; phosphorus ; pollution ; eutrophication
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Elevated phosphate concentrations at Safaga and Quseir, Red Sea, Egyptian coast, wererelated to some ecological and nutritional aspects of the macro-alga Cystoseira myrica during1985. The results obtained were compared with those recorded for a non-polluted control site atGhardaqa. Chemical analysis of surface seawater samples revealed that the concentrations of dissolvedphosphate at Safaga and Quseir were 3 and 20 times as much as that at Ghardaqa, respectively.The standing crop of C. myrica showed two peaks in spring and autumn. Maximum biomass yield(491 g m-2) and number of individuals (127 m-2) of C. myrica were recorded in the spring at theGhardaqa site. Quseir C. myrica samples contained significantly higher protein-N, total-N andtotal-P values but lower carbohydrate values than the Safaga and Ghardaqa samples (LSD at 1%level). Tissue N:P molar ratios for C. myrica, Laurencia papillosa and Ulva lactuca collected fromGhardaqa ranged from 68-98, compared to 30-59 for the same species collected at thephosphorus polluted sites at Safaga and Quseir. The carbon levels and the C:N ratios of C. myricaexhibited no significant variations in the three studied sites. However, the C:P ratios of Ghardaqaplants were significantly higher than those of Safaga and Quseir.
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  • 65
    ISSN: 1573-2932
    Keywords: mercury ; methylmercury ; sediment ; polychaete ; Nereis diversicolor ; methylation ; bioaccumulation ; Scheldt estuary
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Total mercury (Hg) and methylmercury (MeHg) concentrations were determined in sediments and in the polychaete wormNereis diversicolor at 13 stations of a brackish water intertidal mudflat of the Scheldt estuary. Hg and MeHg concentrations in sediments ranged from 144 to 1192 ng g−1 dw and from 0.8 to 6 ng g−1 dw, respectively. Both Hg and MeHg concentrations increased with an increase of organic matter (OM) content and fine grain fraction. In contrast, Hg accumulation byN. diversicolor was significantly (p〈0.05) higher at stations with sandy sediments (mean value: 125 ng g−1 dw) than at stations with muddy sediments (mean value, 80 ng g−1), probably because Hg availability for bioaccumulation at muddy stations was reduced by high OM content of the muddy sediments. MeHg accounted for an average of 0.7% of the total Hg in sediments and 18% of the total Hg inN. diversicolor. Seasonal variations significantly affected Hg concentrations in sediments and MeHg inN. diversicolor. Total Hg concentrations in sediments were significantly (p〈0.05) higher in autumn and winter than in spring and summer whereas MeHg concentrations were lowest in winter compared to the other seasons. On the other hand, total Hg concentrations in the worms were lowest in spring whereas MeHg concentrations were significantly (p〈0.01) higher in spring and summer than in autumn and winter.
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  • 66
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    Water, air & soil pollution 99 (1997), S. 477-486 
    ISSN: 1573-2932
    Keywords: sediment ; nitrogen ; phosphorus ; organic matter ; cluster analysis ; Gulf of Finland ; estuaries
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Dry weight (DW), ignition loss (IL) and concentrations of total nitrogen (TN) and total phosphorus (TP) of the sediment surface layer (0 to 10 cm, 1 cm slices) were analyzed from 20 sites in the eastern Gulf of Finland. The distance of the sampling sites from the mouth of the River Neva explained the nutrient concentrations of the sediments well, while the effect of water depth was negligible. The increase of TN and the decrease of TP along the transect from the river mouth towards the open Gulf were caused by the diminishing share of allochthonous material supplied from the River Neva. The mean TN concentration of the different accumulation areas was about 40 % higher in the sediment surface than in the deeper layer (9 to 10 cm). The corresponding difference for TP varied from 53 to 56 %. The results suggest considerable netflux of nutrients from sediment to water. The net sediment accumulation of nutrients were estimated as 6.0 g m−2 a−1 of N and 1.7 g m−2 a−1 of P corresponding 22 000 t a− of N and 6 100 t a−1 of P for the whole eastern Gulf.
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  • 67
    ISSN: 1573-2932
    Keywords: mercury ; mercury accumulation ; mercury deposition ; North Dakota ; saline lakes ; sediment cores
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Sediment cores were collected from lakes in the Devils Lake Basin in North Dakota to determine if mercury (Hg) accumulation chronologies from sediment-core data are good indicators of variations in Hg accumulation rates in saline lakes. Sediment cores from Creel Bay and Main Bay, Devils Lake were selected for detailed analysis and interpretation. The maximum Hg concentration in the Creel Bay core was 0.15 micrograms per gram at 8 to 9 centimeters. The maximum Hg concentration in the Main Bay core was 0.07 micrograms per gram at 5 to 7 centimeters. The general decreases in Hg concentrations with depth are attributed to historic variations in atmospheric Hg deposition rate. Hg stratigraphies combined with210 Pb and 137Cs dating analyses yield Hg chronologies that indicate a general increase in Hg accumulation rates in Devils Lake since the middle of the 19th century. Mean modern Hg accumulation rates in Creel Bay were 4.9 nanograms per square centimeter per year, and rates in Main Bay were 1.8 nanograms per square centimeter per year. Mean preindustrial Hg accumulation rates in Creel Bay were 1.2 nanograms per square centimeter per year, and rates in Main Bay were 1.6 nanograms per square centimeter per year. Relatively low Hg concentrations in recent sediments in the Devils Lake Basin, along with similarities in Hg accumulation rates between lakes in the Devils Lake Basin and other lakes in the northern interior of North America, indicate that local sources of Hg are not important sources of Hg. Results of the study indicate that accurate Hg chronologies are discernible in sediment cores collected from saline lakes. However, spatial and temporal variations in lake level and water chemistry common to saline lakes make interpretation of radioisotopic and geochemical chronologies difficult. Hg geochemistry in Devils Lake, and presumably in other saline lakes, is dynamic. The results of this study indicate that the absolute amount of sediment transported to Devils Lake, along with the associated Hg and total organic carbon, and the distribution of sedimentation patterns in Devils Lake may be affected by changing lake levels.
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  • 68
    ISSN: 1573-2932
    Keywords: mercury ; mercury accumulation ; mercury deposition ; North Dakota ; saline lakes ; sediment cores
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Sediment cores were collected from lakes in the Devils Lake Basin in North Dakota to determine if mercury (Hg) accumulation chronologies from sediment-core data are good indicators of variations in Hg accumulation rates in saline lakes. Sediment cores from Creel Bay and Main Bay, Devils Lake were selected for detailed analysis and interpretation. The maximum Hg concentration in the Creel Bay core was 0.15 micrograms per gram at 8 to 9 centimeters. The maximum Hg concentration in the Main Bay core was 0.07 micrograms per gram at 5 to 7 centimeters. The general decreases in Hg concentrations with depth are attributed to historic variations in atmospheric Hg deposition rate. Hg stratigraphies combined with210Pb and137Cs dating analyses yield Hg chronologies that indicate a general increase in Hg accumulation rates in Devils Lake since the middle of the 19th century. Mean modern Hg accumulation rates in Creel Bay were 4.9 nanograms per square centimeter per year, and rates in Main Bay were 1.8 nanograms per square centimeter per year. Mean preindustrial Hg accumulation rates in Creel Bay were 1.2 nanograms per square centimeter per year, and rates in Main Bay were 1.6 nanograms per square centimeter per year. Relatively low Hg concentrations in recent sediments in the Devils Lake Basin, along with similarities in Hg accumulation rates between lakes in the Devils Lake Basin and other lakes in the northern interior of North America, indicate that local sources of Hg are not important sources of Hg. Results of the study indicate that accurate Hg chronologies are discernible in sediment cores collected from saline lakes. However, spatial and temporal variations in lake level and water chemistry common to saline lakes make interpretation of radioisotopic and geochemical chronologies difficult. Hg geochemistry in Devils Lake, and presumably in other saline lakes, is dynamic. The results of this study indicate that the absolute amount of sediment transported to Devils Lake, along with the associated Hg and total organic carbon, and the distribution of sedimentation patterns in Devils Lake may be affected by changing lake levels.
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  • 69
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    Water, air & soil pollution 98 (1997), S. 389-399 
    ISSN: 1573-2932
    Keywords: fertilizer ; nitrogen ; pollution ; runoff ; stable isotopes ; sugarcane
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract In many forested wetlands of Louisiana, surface water quality is being deteriorated by nutrient input from adjacent agricultural production area. This field study assesses the input of fertilizer N, applied to sugarcane fields, to forested wetlands. The potential use of natural abundance variations in15N/14N ratios for identification and tracing surface water N sources (NH 4 + - and NO 3 − -N) was evaluated. Runoff and surface water samples were collected from sugarcane fields and bordering forested wetlands (6 stations) over a 16 month period and analyzed for NH 4 + -N, NO 3 − -N, and associated NH 4 + -δ 15N and NO 3 − -δ 15N ratios. FertilizerN draining into adjacent forested wetland was estimated to be only a small fraction of the amount applied. Concentrations of NH 4 + - and NO 3 − -N in the collected water samples were low and ranged from 0.02 to 1.79 mg L−1. Isotopic analysis revealed NH 4 + -δ 15N and NO 3 − -δ 15N means were distinctive and may have the potential to be used as tracers of N contamination. The mean NH 4 + -δ 15N value was +18.6±7.1‰ and the NO 3 − -δ 15N mean was +8.3±3.1‰. Anomalously high NO 3 − -δ 15N values (〉30‰) were attributed to denitrification.
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  • 70
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    Environmental monitoring and assessment 49 (1998), S. 157-168 
    ISSN: 1573-2959
    Keywords: biodiversity ; carbon storage ; climate change ; conservation ; creative destruction ; ecological succession ; ecosystem stability ; Holling figure-eight ; nitrogen ; resilience
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Holling proposed a four-phase conceptual model of ecosystem dynamics that includes exploitation, conservation, and destructive and renewal components to explain the failure of many natural resource management schemes. The model is drawn as a sideways figure-eight i.e. ∞. There are two dimensions in this model, connectivity (abscissa) and the amount of capital stored in the system (ordinate). This conceptual model has been suggested as a guide to thinking about the impact of climate change on biodiversity, but the two dimensions are insufficient and the alignment of the figure-eight model is problematic when compared with actual data. Kay has adjusted the dimensions of the figure-eight model and renamed the abscissa as exergy stored and the ordinate as exergy consumed. We realign the original figure-eight model, labeling the abscissa as carbon stored and the ordinate as nutrients, such that the relative values of both axes are in qualitative agreement with data from four different studies. This new alignment is then shown to fit relatively well with Holling's original labels. This revision of the figure-eight model brings Holling's model into agreement with observations and provides insight into the linkages between biodiversity and climate change.
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  • 71
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    Environmental monitoring and assessment 53 (1998), S. 259-277 
    ISSN: 1573-2959
    Keywords: air quality model ; dispersion model ; industrial source complex model ; mercury ; model evaluation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract The goal of this paper is to compare and evaluate the performance of three air quality regulatory models for mercury releases. The models include Industrial Source Complex Short Term model (ISCST2), Industrial Source Complex Long Term model (ISCLT2), and SCREEN2. The evaluation is conducted in multiple point source urban environment using meteorological data, emission inventory and monitoring data for eight stations for the year 1990 to 1992. The performance of the models is evaluated using eight statistical parameters. The comparison of models results for both quarterly and annual averaging periods shows that ISCST2 predictions qualitatively match the observed concentrations; whereas SCREEN2 predicts highest concentrations and ISCLT2 the lowest concentrations. The summary of statistical analysis obtained by using three different methods of observed concentration (Co) and predicted concentrations (Cp) comparison show that the ISCST2 has a better overall performance than ISCLT2 and SCREEN2 models. However, none of the models met the criteria for a reasonable model. Summaries of 95% confidence limits on normalize mean square error (NMSE), geometric mean variance (VG) and geometric mean bias (MG) for each and among model indicate that of the three models, ISCST2 has the best overall performance indicators. Improved model performance may be achieved by incorporating different types of mercury forms into emission rate and air dispersion calculations.
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  • 72
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    Environmental monitoring and assessment 58 (1999), S. 173-200 
    ISSN: 1573-2959
    Keywords: Baltic Sea ; nitrogen ; phosphorous ; riverine load ; timeseries
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract This article presents the results of the first critical examination of time series of riverine nutrient-load data for the entire Baltic Sea drainage area. Water quality data collected by or for the different national environmental agencies were compiled and analysed statistically to identify and remove inconsistent or obviously incorrect observations. Moreover, sampling tours were undertaken to acquire additional information about the present nutrient concentrations in the largest rivers in the study area. Gaps in the time series of approved data were then filled in by employing statistical interpolation and extrapolation methods. Thereafter, the concentration and runoff data were combined to obtain estimates of monthly nutrient loads for the time period 1970–93. The results of the calculations showed that although there had been substantial changes in land use, atmospheric deposition and wastewater treatment in many parts of the study area, the total riverine loads of nitrogen (N) and phosphorus (P) to the Baltic Sea have been fairly constant since 1980, and most likely also since 1970. Moreover, the interannual variation was clearly correlated to the runoff. The mean annual loads for the time period 1980–93 were found to be about 825 000 tonnes N and 41 000 tonnes P, respectively. This implies that (i) several other investigators have strongly underestimated the riverine loads of nutrients, especially the nitrogen, and that (ii) the riverine loads by far exceed the input to the Baltic Sea from other sources, {i.e.} atmospheric deposition, direct emissions from cities and industries along the Baltic Sea coast and nitrogen fixation by marine algae.
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  • 73
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    Environmental monitoring and assessment 59 (1999), S. 47-72 
    ISSN: 1573-2959
    Keywords: flow-normalisation ; long-term trends ; monitoring ; nitrogen ; riverine load ; statistical analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Concern about nitrogen loads in marine environments has drawn attention to the existence and possible causes of long-term trends in nitrogen transport in rivers. The present study was based on data from the Swedish environmental monitoring programme for surface water quality; the continuity of these data is internationally unique. A recently developed semiparametric method was employed to study the development of relationships between runoff and river transport of nitrogen since 1971; the observed relationships were then used to produce time series of flow-normalised transports for 66 sites in 39 river basins. Subsequent statistical analyses of flow-normalised data revealed only few significant downward trends (p ≤0.05) during the time period 1971–1994, and the most pronounced of these downward trends were caused by reduced point emissions of nitrogen. The number of significant upward trends was substantially larger (15 for total-N and 18 for NO3-N). Closer examination of obtained results revealed the following: (i) the most pronounced upward trends were present downstream of lakes, and (ii) observed increases in nitrogen transport coincided in time and space with reduced point emissions of phosphorus or organic matter. This indicated that changes in the retention of nitrogen in lakes were responsible for the upward nitrogen trends. The hypothesis that nitrogen saturation of forest soils has caused a general increase in the riverine export of nitrogen from forested catchments in Sweden was not confirmed. Neither did the results indicate that improved agricultural practices have reduced the export of nitrogen from agricultural catchments.
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  • 74
    ISSN: 1573-2959
    Keywords: mercury ; mining ; monitoring ; aquatic ; acid mine drainage ; floc ; Clear Lake ; remediation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Mercury (Hg) in the aquatic ecosystem of Clear Lake has been documented since the 1970s when fishes were found to have elevated levels of toxic methyl mercury (meHg). Mining practices at the Sulphur Bank Mercury Mine (active intermittently from 1872–1957) along the shoreline of Clear Lake included the bulldozing of waste rock and overburden ore into the shallow nearshore regions of the lake and the creation of steeply sloped piles of waste rock at the water's edge. This process, plus erosion of the waste rock piles, resulted in the accumulation of an estimated 100 metric tons of Hg in Clear Lake. A monitoring program to assess Hg in Clear Lake was established in 1992, and conducted continuously from 1994. Drought conditions in California had persisted for ca. 6 yrs prior to 1992, when the U.S. Environmental Protection Agency (USEPA) remediated the steeply sloped eroding waste rock piles, which appeared to reduce sediment Hg concentrations significantly. In April 1995, a white flocculent material was observed in Clear Lake adjacent to the mine and has been observed every year since, leading to the discovery of ongoing acid mine drainage (AMD), low pH fluids high in Hg and extremely high in sulfate. AMD is now believed to be the most likely cause of elevated meHg in Clear Lake. The discovery of this source of meHg production in Clear Lake, which will significantly influence remedial options, was only made possible by implementation of a diligent monitoring program.
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  • 75
    ISSN: 1573-3017
    Keywords: mercury ; body distribution ; feather concentrations ; body burden ; tern chicks
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: We studied mercury concentrations and amounts in tissues of 19 starved young Common Tern chicks (median age 4 days) and in eggs from the same colony. Concentrations and burden were similar between eggs and newly hatched chicks. Mercury concentrations were highest in down, which contained at least 38% of the body mercury. The mercury burden of the whole body and of the tissues as well as the concentration in down increased with age and body mass, indicating the importance of down as an elimination pathway. Conversion ratios between mercury concentrations in tissues and the whole chick body varied according to the contamination level.
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  • 76
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    Ecotoxicology 8 (1999), S. 49-56 
    ISSN: 1573-3017
    Keywords: mercury ; methylmercury ; fish ; acidification ; biomagnification
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Two small drainage lakes of similar surface area (0.4–0.6 km 2 ) and depth, and situated in close proximity to one another (about 9 km apart) in the Muskoka-Haliburton district of rural Ontario, Canada were chosen to investigate the effects of differing pH on Hg accumulation in fish and other biota. Blue Chalk Lake is circumneutral (pH = 6.3–6.9) with an average dissolved organic carbon (DOC) concentration of 2.69 mg/L; Plastic Lake is acidic (pH = 5.2–5.6) with a similar DOC level (2.72 mg/L). Neither lake is an impoundment, and neither receives inputs from point-source urban or industrial waste emissions. Surficial (top 4 cm) sediments and various aquatic biota, including crayfish (Orconectes virilis)], and 5 species of fish [brown bullhead (Ictalurus nebulosus), creek chub (Semotilus atromaculatus), pumpkinseed sunfish (Lepomis gibbosus), yellow perch (Perca flavenscens) and rock bass (Ambloplites rupestris)] were sampled for Hg analysis. Only creek chub and pumpkinseed occurred in both lakes. Significant size (length) vs. Hg-concentration relationships were observed for brown bullhead, pumpkinseed, yellow perch and rock bass, but not for crayfish nor for creek chub in either lake. Rock bass had the highest mean Hg concentration (1.02 ± 0.98 μg/g dry wt.). Pumpkinseed from Plastic Lake had the highest overall rate of accumulation with increasing size. Several individual pumpkinseed and rock bass sampled from the acidic Plastic Lake had Hg concentrations equal to or greater than levels reported to be hazardous to breeding piscivorous birds, such as common loons (Gavia immer), whereas no fish from Blue Chalk approached this threshold (0.3 μg/g wet wt). This study illustrates the importance of within-lake parameters, particularly pH, and species trophic level, in determining Hg accumulation in fish in lakes of similar size that receive similar atmospheric Hg inputs.
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  • 77
    ISSN: 1573-2932
    Keywords: atmospheric deposition ; high elevation forests ; foliar uptake ; cloudwater ; nitrogen ; sulphur
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract From 1986–1989, a team of scientists measured atmospheric concentrations and fluxes in precipitation and throughfall, and modeled dry and cloudwater deposition in a spruce-fir forest of the Great Smoky Mountains National Park which is located in the Southern Appalachian Region of the United States. The work was part of the Integrated Forest Study (IFS) conducted at 12 forests in N. America and Europe. The spruce-fir forest at 1740 m consistently received the highest total deposition rates (∼2200, 1200, and 700 eq ha−1 yr−1 for SO4 2−, NO3 −, and NH4 +). During the summers of 1989 and 1990 we used multiple samplers to measure hydrologie, SO4 2−, and NO3 − fluxes in rain and throughfall events beneath spruce forests above (1940 m) and below (1720 m) cloud base. Throughfall was used to estimate total deposition using relationships determined during the IFS. Although the SO4 2− fluxes increased with elevation by a factor of ∼2 due to higher cloudwater interception at 1940 m, the NO3 − fluxes decreased with elevation by ∼30%. To investigate further, we began year round measurements of fluxes of all major ions in throughfall below spruce-fir forests at 1740 m and at 1920 m in 1993–1994. The fluxes of most ions showed a 10–50% increase with elevation due to the ∼70 cm yr−1 cloudwater input at 1920 m. However, total inorganic nitrogen exhibited a 40% lower flux in throughfall at 1920 m than at 1740 m suggesting either higher dry deposition to trees at 1740 m or much higher canopy uptake of nitrogen by trees at 1920 m. Differential canopy absorption of N by trees at different elevations would have significant consequences for the use of throughfall N fluxes to estimate deposition. We used artificial trees to understand the foliar interactions of N.
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    Water, air & soil pollution 85 (1995), S. 1891-1896 
    ISSN: 1573-2932
    Keywords: emissions ; nitrogen ; ammonia ; agriculture ; integrated assessment modelling ; abatement strategies
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract European emissions of reduced nitrogen, arising principally from agriculture, are comparable with those of oxidised nitrogen from mobile and stationary combustion sources. It is therefore important to include ammonia emissions in working towards a new protocol on nitrogen under the programme of the UN Economic Commission for Europe on the control of transboundary air pollution. However the nature of the sources and the subsequent atmospheric transport and chemistry are very different from other acidifying pollutants. This paper describes work in hand under the MARACCAS project to compare agricultural activities in different European countries and to assess the applicability and efficacy of potential abatement measures. The aim is to derive abatement costs for each country relating successive emission reductions to the costs of achieving them, to be used by the UN ECE Task Force on Integrated Assessment Modelling (TFIAM) — in particular with our Abatement Strategies Assessment Model, ASAM. The paper will also address the large uncertainties involved in integrated assessment modelling with respect to ammonia, and suggest how these may be allowed for in deriving cost-effective abatement strategies.
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  • 79
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    Water, air & soil pollution 85 (1995), S. 2375-2380 
    ISSN: 1573-2932
    Keywords: Critical load ; acidity ; nitrogen ; Norway spruce ; Scots pine ; ground vegetation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract The critical loads of acidity and nitrogen has been mapped for Swedish forest soils, using data from the Swedish Forest Inventory. The Swedish critical load map used in negotiations has been based on a number of ecological receptors. For terrestrial ecosystems criteria based on no adverse effect on growth, soil stability and groundwater quality was used. For surface waters, stream and lake biology was used as indicators for setting limits to acidification. A reduction of 75% of the acidity deposition in relation to 1988 is required in order to protect 95% of the forest resource in Sweden from effects of soil acidification. A reduction of 50% of the nitrogen deposition is required to avoid exceedance in more than 5% of the area. The mapping work was carried out by using the PROFILE model.
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  • 80
    ISSN: 1573-2932
    Keywords: critical loads ; nitrogen ; sulphur ; northern Asia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract On the basis of modified simple steady state mass-balance equations, the critical loads for nutrient and acidifying nitrogen as well as for sulphur and acidity have been calculated for various ecosystems of northern Asia using simplified expert-modelling GIS and grid cells 150×150 km. The minimal values of critical loads of nitrogen, CL(N), (〈50eq/ha/yr) were shown for arctic and subarctic ecosystems and the maximal ones (〉300eq/ha/yr) for ecosystems of chernozemic and chernozem-like soils in southern Siberia and the Far East. The minimal values of critical loads of sulphur, CL(S), as well as acidity were shown predominantly in the northern part of east Siberia and in the Kamchatka peninsula and the maximal ones for ecosystems having neutral and alcaline soils. The corresponding exceedances were indicated for many regions of the northern part of Asia with maximal values for regions of Ural mountains, frontery of Kazakhstan, Altai, lower Yenisei river flow, Far East, Sakhalin and South-Kurilean islands.
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  • 81
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    Water, air & soil pollution 85 (1995), S. 2559-2564 
    ISSN: 1573-2932
    Keywords: uncertainty analysis ; computed critical loads ; nitrogen ; sulpher ; acidity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract The goal of this study is to give a comprehensive and quantitative estimation of the uncertainty of computed in different scale nitrogen (N) and sulphur (S) critical loads (CL) values for terrestrial ecosystems of the Northern Asia, European part and the North-Western regions of Russia. The CL values are used to set goals for future deposition rates of acidifying compounds so that the environment is protected. In this research CL values for terrestrial ecosystems are determined using the expert-modelling geoinformation system (EM GIS) approach. UNCSAM software package is used as the tool for uncertainty analysis. The analysis presented here focuses on the estimation and effect of the input source uncertainties and sensitivities on the CL values in various regions under study. In spite of the region, nitrogen uptake by vegetation, nitrogen leaching from terrestrial ecosystems and the difference between deposition and uptake by plants of base cations (BC) are the most influential factors for all terrestrial ecosystems of Russia.
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  • 82
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    Water, air & soil pollution 85 (1995), S. 2619-2624 
    ISSN: 1573-2932
    Keywords: sulphur ; nitrogen ; critical loads function ; emissions reductions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract The roles of sulphur (S) and nitrogen (N) in causing critical loads exceedance across the UK show considerable spatial variability at the present time. Over much of lowland Britain it appears that the environment can only be protected by reducing N deposition, whilst in upland areas (e.g. most of Scotland and Wales) reductions in S deposition are the primary requirement. Using the Hull Acid Rain Model (HARM) the effects of current and possible future emissions control legislation on critical loads exceedance can be explored. Based on HARM output, the implementation of the UNECE Sulphur Protocol (1994) will bring about a substantial reduction in the amount of S being deposited in the UK, especially in central and southern parts of the country. Some areas will remain where additional reductions in S are required. Over most of the country, however, the need to reduce N deposition will become paramount. The changing contributions and significance of non-UK sources can be estimated.
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  • 83
    ISSN: 1573-2932
    Keywords: atmospheric deposition ; ecosystem ; hydrology ; nitrogen ; sulfur
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Information on atmospheric inputs, water chemistry and hydrology were combined to evaluate elemental mass balances and assess temporal changes in elemental transport from 1983 through 1992 for the Arbutus Lake watershed. This watershed is located within a northern hardwood ecosystem at the Huntington Forest within the central Adirondack Mountains of New York (USA). Changes in water chemistry, including increasing NO3 − concentrations (1.1 μmol c , L−1 yr-1), have been detected during this study period. Starting in 1991 hydrological flow has been measured from Arbutus Lake and these measurements were compared with predicted flow using the BROOK2 hydrological simulation model. The model adequately (r2=0.79) simulated flow from this catchment and was used to estimate drainage for earlier periods when direct hydrological measurements were not available. Modeled drainage water losses coupled with estimates of wet and dry atmospheric deposition were used to calculate solute budgets. Export of SO4 2− (831 mol c ha−1 yr−1) from the greater Arbutus Lake watershed exceeded estimates of atmospheric deposition in an adjacent hardwood stand suggesting an additional source of S. These large drainage losses of SO4 2− also contributed to the drainage fluxes of basic cations (Ca2+, Mg2+, K+ and Na+). Most of the atmospheric inputs of inorganic N were retained (average of 74% of wet precipitation and 85% total deposition) in the watershed. There were differences among years (56 to 228 mol ha−1 yr−1) in drainage water losses of N with greatest losses occurring during a warm, wet period (1989–1991).
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  • 84
    ISSN: 1573-2932
    Keywords: Pulp and paper mill sludge ; nitrogen ; DOC ; heavy metals ; water quality
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Primary sludge, secondary sludge, and wood ash from a pulp and paper mill were combined with sand to create a synthetic topsoil (C:N ratio of 18:1) to restore an abandoned gravel pit. Synthetic topsoil was applied to field microcosms at rates equivalent to 0, 2170, 4341, or 6511 kg N/ha; each was seeded with grass. Fifteen chemical constituents in leachate were measured during two field seasons. Cadmium, Ni and Zn were mobilized rapidly by soil disturbance. Chloride and SO4-S eluted rapidly from the sludge along with Na. Nitrate leached with Ca late in each field season when sludge N-mineralization and nitrification exceeded plant uptake and microbial immobilization. Ammonium elution was negligible. Dissolved organic carbon (DOC) was mobilized by decomposition of organic matter in the sludge, as were Mg and K. Copper eluted with DOC, probably as an organic ligand. Lead and ortho-P were below our detection limits. We concluded that a synthetic topsoil with a 30:1 C:N ratio applied at a rate of 2100-4300 kg N/ha should provide adequate plant nutrition while minimizing water quality hazards.
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  • 85
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    Water, air & soil pollution 95 (1997), S. 35-43 
    ISSN: 1573-2932
    Keywords: humic acid ; mercury ; transport ; transformation ; soil-plant system
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract The influence of humic acid (HA) on the transport and transformation of mercury (Hg) in soil was studied. No available Hg could be detected (〈2.5 μg kg−1) in alluvial soil when the content of HA-carbon (HA-C) was higher than 0.2 g kg−1 although a large amount of Hg (8 μg kg−1) was applied to the soil. The available Hg decreased with the increase of HA in purple soil (r=0.735). There are significant correlations between HA concentration and organic Hg in the tested soils (r=0.974 for the purple soil and r=0.979 for the alluvial soil). The increase of HA results in decrease of Hg absorbed by plant from the soil. A loss of Hg from soil caused by microbes was observed.
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  • 86
    ISSN: 1573-2932
    Keywords: sulphur ; nitrogen ; Scandinavia ; long distance transport ; elemental tracers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Long distance transport of various air pollutants has been studied at two Scandinavian coastal sites. The measuring period has covered one year divided into 4 campaigns. Seasonal variations for sulphur and nitrogen compounds as well as anthropogenically emitted metals are reported. Concentrations of Pb and Zn as well as the ratio of V/Ni concentrations have been used to trace sulphuric episodes. Covariation of anthropogenic pollutants for the two sites is demonstrated.
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  • 87
    ISSN: 1573-2932
    Keywords: acid rain ; batch experiment ; Freundlich isotherm ; lysimeter experiment ; mercury ; simulation model
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Increasing mercury contents are reported from freshwater systems and fish in northern Europe and North America. Mercury input from soils is a major source with the leaching being affected by increased atmospheric mercury deposition compared to pre-industrial times and by other environmental conditions such as acid rain. The results of a mathematical model-calculation of vertical inorganic Hg(II) leaching in a Scandinavian iron-humus podzol under different atmospheric input rates of mercury are presented. Leaching under background rain conditions was calculated to be considerably stronger than under acid rain conditions. Increasing fractions of deposited soluble or solute atmospheric mercury were leached from the O f(h)-horizon with decreasing soil content of soluble mercury under acid rain conditions; this effect was less pronounced under background rain conditions. The steady state concentrations of soluble mercury of the upper soil horizons were calculated and compared with the actual concentrations of total (= soluble + insoluble mercury) and extractable (= estimate of soluble) mercury measured in these horizons. The results indicate that even if the deposition of airborne mercury to soil is strongly reduced, the total mercury content of the soil decreases only slowly. It may take decades or even centuries before a new steady state concentration of total mercury is established in the soil. The decrease of the mercury concentration in the O f(h)-horizon is probably largely dependent on the turnover of organic matter, binding most of the deposited airborne mercury in an insoluble form. Hence, present day mercury leaching is likely to be dominated by mercury deposited during former times and temporarily retained in an insoluble form in the organic matter.
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  • 88
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    Water, air & soil pollution 96 (1997), S. 329-345 
    ISSN: 1573-2932
    Keywords: beech ; biomonitoring ; nitrogen ; solid particles ; spruce ; sulphur
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract The foliage contents of Stotal and Ntotal were determined in 405 Permanent monitoring plots in four National Parks and sixteen Landscape Protection Areas and were compared with 1483 Permanent monitoring plots on Slovakia. The foliage content of S ranged from 0.72 to 6.77 g kg−1 in hardwoods and from 0.98 to 4.3 g kg−1 in softwoods. A critical increase was determined in one National Park and in four Landscape Protection Areas. The foliage content of N ranged from 9.7 to 48.7 g kg−1 in softwoods, and from 7.8 to 51.4 g kg−1 in hardwoods. An insufficient level of N was determined in one Landscape Protection Area and a critical increase in four Landscape Protection Areas. The sulphur to nitrogen ratio ranged from 0.08 to 0.176 in softwoods, and from 0.078 to 0.253 in hardwoods. The foliage surface on hitherto explored four National Parks and sixteen Landscape Protection Areas in network 4×4 km was covered by all categories of rigid fallout particles. Fly-ash from coal combustion were observed each of National Parks and Landscape Protection Areas by scanning electron microscopy. Mycelia and spore, mineral matters, sand and soil particles were present on all National Parks and Landscape Protection Areas. Particles derived from aluminium production were observed at three Landscape Protection Areas. Particles derived from cement production and from lime works were observed at two National Parks and six Landscape Protection Areas. Particles derived from ferrous metals industry were observed at each of National Parks and Landscape Protection Areas and particles typical for other technologies were present in three of National Parks and twelve Landscape Protection Areas.
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  • 89
    ISSN: 1573-2932
    Keywords: acid rain ; batch experiment ; Freundlich isotherm ; lysimeter experiment ; mercury ; simulation model
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Increasing mercury contents are reported from freshwater systems and fish in northern Europe and North America. Mercury input from soils is a major source with the leaching being affected by increased atmospheric mercury deposition compared to pre-industrial times and by other environmental conditions such as acid rain. The results of a mathematical model-calculation of vertical inorganic Hg(II) leaching in a Scandinavian iron-humus podzol under different atmospheric input rates of mercury are presented. Leaching under background rain conditions was calculated to be considerably stronger than under acid rain conditions. Increasing fractions of deposited soluble or solute atmospheric mercury were leached from the O f(h)-horizon with decreasing soil content of soluble mercury under acid rain conditions; this effect was less pronounced under background rain conditions. The steady state concentrations of soluble mercury of the upper soil horizons were calculated and compared with the actual concentrations of total (= soluble + insoluble mercury) and extractable (= estimate of soluble) mercury measured in these horizons. The results indicate that even if the deposition of airborne mercury to soil is strongly reduced, the total mercury content of the soil decreases only slowly. It may take decades or even centuries before a new steady state concentration of total mercury is established in the soil. The decrease of the mercury concentration in the O f(h)-horizon is probably largely dependent on the turnover of organic matter, binding most of the deposited airborne mercury in an insoluble form. Hence, present day mercury leaching is likely to be dominated by mercury deposited during former times and temporarily retained in an insoluble form in the organic matter.
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  • 90
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    Water, air & soil pollution 96 (1997), S. 329-345 
    ISSN: 1573-2932
    Keywords: beech ; biomonitoring ; nitrogen ; solid particles ; spruce ; sulphur
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract The foliage contents of Stotal and Ntotal were determined in 405 Permanent monitoring plots in four National Parks and sixteen Landscape Protection Areas and were compared with 1483 Permanent monitoring plots on Slovakia. The foliage content of S ranged from 0.72 to 6.77 g kg-1 in hardwoods and from 0.98 to 4.3 g kg-1 in softwoods. A critical increase was determined in one National Park and in four Landscape Protection Areas. The foliage content of N ranged from 9.7 to 48.7 g kg-1 in softwoods, and from 7.8 to 51.4 g kg -1 in hardwoods. An insufficient level of N was determined in one Landscape Protection Area and a critical increase in four Landscape Protection Areas. The sulphur to nitrogen ratio ranged from 0.08 to 0.176 in softwoods, and from 0.078 to 0.253 in hardwoods. The foliage surface on hitherto explored four National Parks and sixteen Landscape Protection Areas in network 4 × 4 km was covered by all categories of rigid fall-out particles. Fly-ash from coal combustion were observed each of National Parks and Landscape Protection Areas by scanning electron microscopy. Mycelia and spore, mineral matters, sand and soil particles were present on all National Parks and Landscape Protection Areas. Particles derived from aluminium production were observed at three Landscape Protection Areas. Particles derived from cement production and from lime works were observed at two National Parks and six Landscape Protection Areas. Particles derived from ferrous metals industry were observed at each of National Parks and Landscape Protection Areas and particles typical for other technologies were present in three of National Parks and twelve Landscape Protection Areas.
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  • 91
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    Environmental monitoring and assessment 63 (2000), S. 431-446 
    ISSN: 1573-2959
    Keywords: aquatic bacteria ; benthic macroinvertebrates ; bioindicator ; eutrophication ; nitrogen ; phosphorus ; stream pollution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract A combination field and laboratorystudy was conducted to evaluate the ability of arecently developed bioindicator to detect detrimentalnutrient conditions in streams. The method utilizesbacterial growth on aquatic insects to determinenutrient impacts. Field investigations indicated thatelevated concentrations of nitrate and phosphate wereassociated with growth of filamentous bacteria oninsect body surfaces, and that there was a significantreduction in the density of major insect taxa in thenutrient-enriched stream reaches. Laboratoryinvestigations confirmed a strong linkage betweenbacterial growth and reduced survival of insects. Survival was examined for insects with bacterialinfestation ranging from 0% to greater than 50%coverage of the body surface. A threshold forcatastrophic mortality occurred at about 25% bodycoverage; there were few survivors above that amount. Based on these findings, the diagnostic endpoint forthe bioindicator is 25% body coverage by bacterialgrowth, a level that signifies major impacts and isalso easy to detect visually. This study providesadditional evidence that the insect-bacteriabioindicator is a reliable tool for assessing nutrientimpacts on stream macroinvertebrate communities. Thebioindicator should prove useful for identifyingnutrient-impacted sites as well as monitoring thesuccess of management actions to improve water quality.
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  • 92
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    Environmental monitoring and assessment 64 (2000), S. 409-419 
    ISSN: 1573-2959
    Keywords: monitoring ; assessment ; water ; sediment ; bioaccumulation ; toxicity ; pesticides ; mercury ; PCB
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract The San Francisco Estuary Regional Monitoring Program for Trace Substances (RMP) began in 1993 and is sponsored by 74 local, state, and federal agencies and companies through their discharge or Bay use permits. The RMP monitors water, sediment, toxicity, and bivalve bioaccumulation at 25 sites in the Bay that are considered to represent "background" conditions. Several major environmental issues have been identified by the RMP. Polychlorinated biphenyls and mercury were often above water quality guidelines, and often occurred in fish tissues above U.S. Environmental Protection Agency (U.S. EPA) screening values. Concentrations do not appear to be decreasing, suggesting continuing inputs. Episodes of aquatic toxicity often occurred following runoff events that transport contaminants into the Bay from urbanized and agricultural portions of the watershed. Sediment toxicity occurred throughout the Bay, and has been correlated with concentrations of specific contaminants (chlordanes, polynuclear aromatic hydrocarbons) at some locations; mixtures of contaminants were probably also important. Since the RMP does not monitor all ecosystem components, assessments of the overall condition of the Bay cannot be made. However, in terms of contamination, the RMP samples suggest that the South Bay, and North Bay sites are moderately contaminated.
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  • 93
    ISSN: 1573-3017
    Keywords: fish ; mercury ; natural selection ; allozyme ; population
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Measurements of the differential tolerance between enzyme genotypes and shifts in allozyme frequencies in populations from contaminated habitats have prompted the use of allozymes as markers of population-level toxicant effects. However, such studies often do not consider other factors that influence allele frequencies, including natural clines, migration, the intensity and specificity of selection and toxicant-induced genetic bottlenecks. In addition, selection components other than survival are not included. Consequently, the associated conclusions remain speculative. To assess this approach rigorously, a simulation study was conducted with the mosquitofish (Gambusia holbrooki) GPI-2 locus. Laboratory studies have shown the GPI-238/38 homozygote at this locus to be less tolerant than other genotypes during acute exposure to mercury. The GPI-2100/100 genotype has also been shown to have a reproductive disadvantage at lower mercury concentrations. Simple and then more complex models were used to quantify the relative effects of viability selection, random genetic drift and migration on the GPI-238 allele frequency. Simulations were also performed to assess the contribution of sexual and fecundity selection. A simple population model suggested that viability selection plays a greater role than does mortality-driven, genetic drift in the decrease of the sensitive allele under the conditions of this study. A more complex, stochastic model indicated that no significant mortality-driven drift was taking place in this system. In both models, migration mitigated the effect of selection. Sexual and fecundity selection had little effect on the allele frequencies in these simulations. We conclude that, provided the system under study is clearly understood, shifts in allele frequency can indicate the population-level effects of pollutants.
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  • 94
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    Water, air & soil pollution 85 (1995), S. 15-24 
    ISSN: 1573-2932
    Keywords: Acid deposition ; global change ; Asia ; fertilizer ; nitrogen ; sulfur
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Most acid-deposition investigations have been concerned with the impact of nitrogen oxides (NOx) and sulfur dioxide (SO2) emissions on Europe and North America. This paper examines three issues beyond this central focus. Major conclusions are 1) ammonia (NH3) emissions and subsequent nitrogen (N) accumulation in terrestrial ecosystems have the potential to generate significant acidification in terrestrial and aquatic ecosystems; 2) sulfur (S) and N accumulation in environmental reservoirs will not only result in significant and extensive acidification but will also impact the earth's radiation balance, tropospheric oxidizing capacity, ecosystem nutrient balance and groundwater quality; and 3) future emissions will substantially increase in the developing world, especially in Asia. By 2020, Asian emissions of SO2, NOx and NH3 will be equal to or greater than the combined emissions from Europe and North America.
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  • 95
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    Water, air & soil pollution 85 (1995), S. 101-110 
    ISSN: 1573-2932
    Keywords: carbon ; nitrogen ; sulfur ; biogeochemistry ; mitigation ; global change
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Forest systems cover more than 4.1×109 ha of the Earth's land area. The future response and feedbacks of forest systems to atmospheric pollutants and projected climate change may be significant. Boreal, temperate and tropical forest systems play a prominent role in carbon (C), nitrogen (N) and sulfur (S) biogeochemical cycles at regional and global scales. The timing and magnitude of future changes in forest systems will depend on environmental factors such as a changing global climate, an accumulation of CO2 in the atmosphere, and increase global mineralization of nutrients such as N and S. The interactive effects of all these factors on the world's forest regions are complex and not intuitively obvious and are likely to differ among geographic regions. Although the potential effects of some atmospheric pollutants on forest systems have been observed or simulated, large uncertainty exists in our ability to project future forest distribution, composition and productivity under transient or nontransient global climate change scenarios. The potential to manage and adapt forests to future global environmental conditions varies widely among nations. Mitigation practices, such as liming or fertilization to ameliorate excess NOx or SOx or forest management to sequester CO2 are now being applied in selected nations worldwide.
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  • 96
    ISSN: 1573-2932
    Keywords: sitka spruce ; nitrogen ; deposition ; leaching ; proton production ; green spruce aphid
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Studies of biogeochemical cycling and soil acidification have been carried out in even aged stands of Norway spruce, sitka spruce, Douglas fir, beech and oak under the frame of “The Element Cycling Project”. Deposition of excess nitrogen to forests is important as a potential acidifying input. In Denmark, reduced vitality in Norway spruce has promoted extensive planting of sitka spruce. However, several spruce aphid infestations have caused defoliation in many sitka spruce stands. The objectives of this study were to evaluate the effects of deposition and increased litterfall due to spruce aphid infestations on nitrogen transformations in the forest floor in sitka spruce stands on different soil types. The deposition of throughfall nitrogen range from 19 to 35 kg/ha/year. Fluxes of nitrogen in litterfall ranged from 21 to 77 kg/ha/year, whereas nitrogen leaching range from 1 to 57 kg/ha/year. Leaching was lowest at the infertile sites, but increased with magnitude of deposition and aphid infestations. Proton production according to the nitrogen transformations was largest at the fertile site most often affected by infestations. Huge amounts of bird droppings, honey dew and input of easily available nutrients by canopy leaching probably induced litter decomposition and formation of NO 3 − in the soil water.
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  • 97
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    Water, air & soil pollution 85 (1995), S. 1239-1244 
    ISSN: 1573-2932
    Keywords: vegetation ; mosses ; bottom layer ; biomass ; Pleurozium schreberi ; Dicranum polysetum ; nitrogen ; deposition ; sulphur deposition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract The response of forest-floor mosses to deposition of nitrogen (N) and sulphur (S) was examined in field conditions in a 60-year-old Norway spruce (Picea abies Karst.) stand in southern Finland. The experimental plots received nitrogen (25 kg N ha−1) and sulphur (30 kg S ha−1) as ammonium sulphate once a year for 4 years. The dominant moss species on the site were Pleurozium schreberi (Mitt.) and Dicranum polysetum (Sw.). The biomass of the dominant moss species was decreased significantly by N and S deposition during the study period. Due to the addition of N and S, the biomass of Pleurozium schreberi was decreased by 60% and the biomass of Dicranum polysetum by 78%. The forest-floor mosses seemed to be more sensitive to nitrogen and sulphur deposition than vascular plants were. Since bryophytes lack a cuticle and absorb water very rapidly after rain episodes, they are more exposed to the direct effects of acid deposition. Thus, mosses may indicate changes in forest vegetation due to acidic deposition. Boreal coniferous forests are characterised by a thick moss layer, which has low thermal conductivity and high water-absorbing capacity. Loss of the moss layer may expose the underlying soil ecosystem to desiccation and to greater variation in temperature. On the other hand, destruction of the moss layer may improve the regeneration of vascular plants.
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  • 98
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    Water, air & soil pollution 85 (1995), S. 1331-1336 
    ISSN: 1573-2932
    Keywords: Betula pendula ; clones ; ozone ; nitrogen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Saplings of five birch clones (Betula pendula Roth.) were exposed to ozone doses 1.2–1.7 × higher than the ambient under field conditions during growing seasons 1991–1993. The clones were also fumigated with 40 ppb – 150 ppb ozone in three chamber experiments.The effects of nitrogen supply on ozone responses were studied using field fumigation system and three levels of nitrogen supply (low, medium, high). The ozone-sensitivity was clone-spesific. Even low ozone exposure decreased the biomass production of the most sensitive clone, whereas the most tolerant clone showed unaffected growth rate. In all clones, ozone fumigation accelerated autumn senescence of leaves, increased ultrastructural injuries, especially in chloroplasts, and increased diffusion resistance and stomatal density of leaves. Ozone-induced changes in the tissue and fine structure of leaves were interpreted as enhanced senescence. The plants receiving high nitrogen supply were more resistant to ozone than the plants under lower nitrogen availability. Significant interactions between ozone and nitrogen supply were found in growth and leaf anatomical parameters. The ozone sensitivity and the growth rate of birch clones seem to be related to biochemical and ultrastructural changes of chloroplasts, as reduced growth rate of the most sensitive clone was accompanied by lower contents of Rubisco small subunit and chlorophyll, and lower net photosynthesis. Fast enlarging and young mature leaves without acclimation were more sensitive to ozone fumigation than the leaves emerging under ozone stress.
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  • 99
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    Water, air & soil pollution 85 (1995), S. 1063-1068 
    ISSN: 1573-2932
    Keywords: soil acidification ; nitrogen ; vegetation changes ; forest vitality ; critical loads
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Effects of elevated S and N deposition on the solution chemistry of Dutch forest soils are mainly manifested by increased concentrations of Al associated with increased concentrations of SO4 and NO4. Presumed critical Al/base cation ratios are often exceeded below 20 cm soil depth. There is also evidence that elevated N deposion during the last decades affected the forest nutrient status and caused large changes in forest vegetation. About half of the Dutch forests have absolute shortage of P and relative Mg deficiencies compared to foliar N contents. Evidence from field studies of a relationship between soil acidification and nutrient imbalances in the soil and the foliage on one hand and the vitality of forests on the other hand is, however, lacking.
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  • 100
    ISSN: 1573-1642
    Keywords: nitrogen ; phosphorus ; macroalgae ; estuary ; anthropogenic
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Our objective was to begin to investigate sources, sinks, and flux rates of nitrogen (N) and phosphorus (P) in Famosa Slough, a small (12 ha) highly modified urban estuary in San Diego, California, U.S.A. The hydrology of Famosa Slough has been modified by culverts that dampen tidal influence and seasonal runoff from two urban watersheds, each of which has been implicated as a nutrient source that generates nuisance algal blooms. In 1995 and 1996, the ranges of nutrients measured in the water column were extremely wide; upper values exceeded those in other estuaries identified as eutrophic. Average dissolved inorganic nitrogen ranged from 2 to 250 μM, while dissolved inorganic phosphorus ranged from 〈1 to 15 μM. Nutrient content of the water changed rapidly both spatially and temporally depending on the tides and rainfall. While tidal water dominated this system, especially in the dry season, our results indicate that Famosa Slough's small watershed, not the larger watershed of the San Diego River, was the major source of nutrients during rainfall. Sediment nutrients were also high (∼3 mg N g dry wt−1 and 0.600 mg P g dry wt−1). Short-term flux studies suggest that the large accumulations of opportunistic green macroalgae commonly found in this estuary, and possibly the sediments, may act as a large and rapid sink for nutrients during times of high nutrient supply. We suggest that small, shallow estuaries in urban settings may have more complex and rapid nutrient dynamics than those found in larger systems.
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