Chemistry of small Norwegian lakes, with special reference to acid precipitation 1

Wright, Richard F.; Henriksen, A.

doi:10.4319/lo.1978.23.3.0487

Cited by 102 publications

(39 citation statements)

References 15 publications

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“…High sea-salt deposition and ion exchange processes in peat deposits can make water bodies prone to ecologically significant acidity pulses (Harriman et al, 1995Bonjean et al, 2007). Because the Na : Cl ratios for the Falkland Islands sites are so close to the theoretical seawater ratio (0.86), seasalt corrections were possible and these can help identify other ion sources (Wright & Henriksen, 1978). When sea-salt corrections are made, negative relationships for chloride with non-marine sodium, magnesium and sulphate are revealed, indicating catchment retention of these ions.…”

Section: Water Chemistrymentioning

confidence: 99%

On the factors affecting distributions of freshwater diatom species in a remote South Atlantic archipelago

Flower

Kernan

Noon³

et al. 2012

European Journal of Phycology

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Diatom species distributions on remote islands are influenced by both habitat quality and location. In this study diatom distributions and water quality were explored in the Falkland Islands archipelago with reference to island floras elsewhere, using 28 freshwater sites (small ponds, shallow lowland lakes, upland tarns and several streams). Site water chemistries varied from strongly acid to circum-neutral and from low to high conductivity and water-colour. Dissolved ions co-varied with conductivity and varied strongly between sites and ion ratios indicated a strong influence of sea-salt deposition. Canonical Correspondence Analysis of the diatom and environmental data revealed three groups of sites, (1) high water-colour and low pH, (2) low conductivity and low water-colour, and (3) high conductivity and higher pH. Diatom species frequency abundances were most strongly influenced by water conductivity and pH. Diatom assemblages were composed of both cosmopolitan and regionally endemic Subantarctic species. Water chemistry was a weak predictor of diatom diversity but sites with more regionally endemic species tended also to have more cosmopolitan species. Taxonomic harmonization allowed species comparisons to be made with diatom assemblages on two islands elsewhere, Signy Island (Antarctica) and South Uist (Scottish Outer Hebrides). Detrended Correspondence Analysis of the species data from these three locations strongly discriminated the Signy Island sites and Subantarctic species characterized the Falkland Islands samples. Regionally endemic species groups within the Subantarctic zone were configured by biogeographical controls on dispersal, as well as by habitat selection and water quality. Variance partitioning showed that water chemistry and spatial (location) variables were both highly significant in accounting for similar proportions of unique variance in the combined island-species dataset. Despite overall low diversity, Subantarctic species are an important floral component and need to be incorporated into global freshwater diatom diversity patterns by using species-sensitive and carefully harmonized datasets.

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Section: Water Chemistrymentioning

confidence: 99%

On the factors affecting distributions of freshwater diatom species in a remote South Atlantic archipelago

Flower

Kernan

Noon³

et al. 2012

European Journal of Phycology

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“…The breakthrough came when scientists realized that the key to understanding surface-water acidification lay in the amount and source of the accompanying anion rather than in the acid itself. Two factors proved necessary to explain surface-water acidification: The water must be acid-sensitive, and the area must receive sufficient amounts of acid deposition (2).…”

Section: A Short Historymentioning

confidence: 99%

Recovery of Acidified European Surface Waters

Wright¹,

Larssen²,

Camarero³

et al. 2005

Environ. Sci. Technol.

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119

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“…For 26 of the 60 lakes in the dataset there are observations from the 197475 regional surveys (Wright and Henriksen, 1978;Wright and Snekvik, 1978) as well as annual measurements from 1986 as part of the national monitoring programme (SFT, 2002). Most of the lakes showed statistically significant decreases in SO 4 * concentrations during the period 199099 (Skjelkvåle et al, 2001b).…”

Section: Calibrationmentioning

confidence: 99%

“…Comparable maps for ANC show a more complicated geographic pattern of absolute ANC levels (Fig. 11), related not only to the acidification caused by sulphur deposition, but also to the inherent sensitivity to acidification related to soil characteristics such as weathering rate of base cations (Wright and Henriksen, 1978). The MAGIC results indicated that, prior to the onset of acid deposition, none of the lakes had ANC below 0 µeq l -1 , in the calibration years 199597 the majority had ANC below 20 µeq l 1 , while by 2016 and 2036 many of the lakes were predicted to recover to above 20 µeq l , and future forecast assuming CLE scenario is implemented (2016 and 2036).…”

Section: Hindcasts and Forecastsmentioning

confidence: 99%

“…Observations are available for a set of 60 small headwater lakes sampled annually since 1986 (35 lakes) or 1995 (25 lakes) as part of the Norwegian national monitoring programme for long-range transported polluted air and precipitation (SFT, 2002). Twenty-six of the lakes were also sampled once in 1974 or 1975 (Wright and Henriksen, 1978;Wright and Snekvik, 1978). The trends in water chemistry in the 1990s in these lakes together with similar lakes in Sweden and Finland have been assessed by Skjelkvåle et al (2001b).…”

Section: Introductionmentioning

confidence: 99%

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Future recovery of acidified lakes in southern Norway predicted by the MAGIC model

Wright

Cosby

2003

Hydrol. Earth Syst. Sci.

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The acidification model MAGIC was used to predict recovery of small lakes in southernmost Norway to future reduction of acid deposition. A set of 60 small headwater lakes was sampled annually from either 1986 (35 lakes) or 1995 (25 lakes). Future acid deposition was assumed to follow implementation of current agreed legislation, including the Gothenburg protocol. Three scenarios of future N retention were used. Calibration of the sites to the observed time trends (19901999) as well as to one point in time considerably increased the robustness of the predictions. The modelled decline in SO 4 * concentrations in the lakes over the period 19862001 matched the observed decline closely. This strongly suggests that soil processes such as SO 4 adsorption/desorption and S reduction/oxidation do not delay the response of runoff by more than a few years. The slope of time trends in ANC over the period of observations was less steep than that observed, perhaps because the entire soil column does not interact actively with the soilwater that emerges as runoff. The lakes showed widely differing time trends in NO 3 concentrations over the period 19862000. The observed trends were not simulated by any of the three N scenarios. A model based on the C/ N ratio in soil was insufficient to account for N retention and leaching at these sites. The large differences in modelled NO 3 , however, produced only minor differences in ANC between the three scenarios. In the year 2050, the difference was only about 5 µeq l -1 . Future climate change entailing warming and increased precipitation could also increase NO 3 loss to surface waters. SO 4 * concentrations in the lakes were predicted to decrease in parallel with the future decreases in S deposition. Fully 80% of the expected decline to year 2025, however, had already occurred by the year 2000. Similarly, ANC concentrations were predicted to increase in the future, but again about 67% of the expected change has already occurred over the past 20 years. The recovery of ANC was predicted to be incomplete. Even after the CLE scenario (for future acid deposition) is implemented, the chemical conditions in about one-third of the lakes were predicted to be insufficient to support trout populations in the future. Thus, additional measures will be required if these lakes are to be restored.

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Chemistry of small Norwegian lakes, with special reference to acid precipitation 1

Cited by 102 publications

References 15 publications

On the factors affecting distributions of freshwater diatom species in a remote South Atlantic archipelago

On the factors affecting distributions of freshwater diatom species in a remote South Atlantic archipelago

Recovery of Acidified European Surface Waters

Future recovery of acidified lakes in southern Norway predicted by the MAGIC model

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