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[Use of an air flow model for dimensioning in-situ plants (vacuum extraction) [MODAIR]]
1998
Hansen, M.C.
[The aquifer Ribe formation: a cross-county mapping project]
1998
Friborg, R. | Thomsen, S.
Danish and US experience on the use of oxygen release compound (ORC)
1998
Gobins, J.
[Priority tools for remediation of deposits and zonation in the Herning/Ikast area]
1998
Sandersen, P. | Hansen, M.C. | Kuerstein, J.
[Mapping and elimination of free DNAPL-phase below the groundwater table]
1998
Christensen, A.G. | Fischer, E.V. | Aktor, H. | Jensen, J.D. | Jensen, C.B.
[In-situ remediation by oxygen injection of limestone polluted with petrol]
1998
Larsen, L.C.
Effects of Afforestation on Acidity and Invertebrates in Danish Streams and Implications for Freshwater Communities in Denmark
1998
Friberg, Nikolai | Rebsdrof, Aage | Larsen, Søren
The relationship between acidity and benthic invertebrate communities was investigated in two small streams in coniferous forests in central Jutland, Denmark, during 1992 and 1993. Stream pH was acid (mean pH 4.8 and 5.4) and alkalinity fluctuated greatly with mean values around zero. During rain events, water from springfed reaches upstream were mixed downstream with brown humic acid water with high aluminium content, and pH declined from circumneutral near the springs down to pH below 4 over a very short distance (0.5–1.5 km). The benthic invertebrate communities in the most acidic downstream reaches of both streams were dominated by filipalpian stoneflies, mainly Leuctra nigra (Olv.). Community composition remained very similar throughout the sampling period despite variations in pH. In the upper (neutral) reaches invertebrates intolerant of low pH such as Gammarus pulex L. were found. The concentrations of chloride and sulphate in the streams were more than double the concentrations in a nearby moorland stream indicating a strong impact of acidifying atmospheric deposition on the two forest streams. Results of this study indicate that afforestation with conifers on sandy Danish soils with low buffering capacity (about 25% of the total Danish land area) may lead to an increased acidification of surface waters and thereby also to an impoverished aquatic fauna.
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