| 1. |
- Bengtsson, Lars, et al.
(författare)
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Water balance for landfills of different age
- 1994
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Ingår i: Journal of Hydrology. - 0022-1694 .- 1879-2707. ; 158:3-4, s. 203-217
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Tidskriftsartikel (refereegranskat)abstract
- Water-related processes in landfills are discussed with emphasis on internal processes such as field capacity, moisture variation in time and space, and macropore flow. Runoff production and evaporation from landfills in Sweden of different age are investigated. It is clarified in what ways and for how long a closed municipal landfill differs from an ordinary land area from a hydrological point of view.
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| 2. |
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| 3. |
- Ek, H., et al.
(författare)
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Growth and assimilation of NH4+ and NO3- by Paxillus involutus in association with Betula pendula and Picea abies as affected by substrate pH
- 1994
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Ingår i: New Phytologist. - : Wiley. - 1469-8137 .- 0028-646X. ; 128:4, s. 629-637
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Tidskriftsartikel (refereegranskat)abstract
- The influence of pH on the growth and assimilation of N-15-labelled ammonium and nitrate was studied in intact ectomycorrhizal systems consisting of Betula pendula Roth and Picea abies (L.) Karst. colonized with a common mycelium of Paxillus involutus (Batsch) Fr. The plants were grown together in Plexiglass observation chambers containing non-sterile peat with three different pH values, 4.0, 5.1 and 6.1. The mycorrhizal mycelium was allowed to grow over a barrier into an area of peat from which plant roots were excluded. Labelled NH4NO3 was supplied, either as (NH4NO3)-N-15 or as (NH4NO3)-N-15, exclusively to the fungal mycelium. Shoots and roots were analyzed for N-15 in total nitrogen while the mycelium was analyzed for N-15 in NH4+, NO3- and free amino acids. The N-15 labelling pattern indicated that ammonium was immediately assimilated into amino acids, primarily glutamine, by the fungal mycelium at the uptake site. The amino acids were then translocated to the mycorrhizal roots. In contrast, nitrate-N was not assimilated in the mycelium but rather transferred to the mycorrhizal roots as nitrate. Mycelial uptake and transfer of N to the spruce and birch seedlings were significantly higher for NH4-N than for NO3-N. No firm conclusions about pH effects on the preferential uptake of ammonium and nitrate could be drawn. However, pH had a pronounced effect on the mycelial growth of P. involutus which was hampered severely at pH 6.1 and to a lesser extent at pH 5.1.
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| 4. |
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| 5. |
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| 6. |
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| 7. |
- Hammarlund, Dan, et al.
(författare)
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A Late Weichselian Stable-Isotope Stratigraphy Compared with Biostratigraphical Data - A Case-Study from Southern Sweden
- 1994
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Ingår i: Journal of Quaternary Science. - : Wiley. - 1099-1417 .- 0267-8179. ; 9:1, s. 13-31
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Tidskriftsartikel (refereegranskat)abstract
- Late Weichselian lake sediments from a site in southern Sweden, were analysed for stable carbon and oxygen isotopes, as well as plant macrofossils and insect remains. By comparison of independent data sets, general climatic changes were demonstrated. Lithological, chemical and stable isotope data reveal two significant climatic oscillations at ca. 12 200-12 000 and ca. 11 000-10 200 yr BP respectively. Continental climatic conditions, indicated by evaporative enrichment of O-18 in lake marl, characterise parts of the early lake history, including the Older Dryas Stadial. Distinct variations of deltaC-13 in organic material is discussed in terms of climatically induced changes in lake-water chemistry. Different types of photosynthetic assimilation of dissolved inorganic carbon is proposed as a contributing factor influencing lake marl deltaC-13. The universal application of a positive correlation between lake marl deltaO-18 and mean annual air temperature is questioned. Quantifications of mean summer and winter temperatures based on beetle analysis show a climatic optimum around 12 000 yr BP, a marked cooling around 11 000 yr BP and a strong amelioration at ca. 10 200 yr BP. These climatic events were accompanied by distinct changes in aquatic vegetation. Plant macrofossil and insect analyses indicate an open vegetation during the entire period studied. Biostratigraphical data reflecting local limnic and terrestrial vegetation and regional climate facilitate the interpretation of stable isotope data.
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| 8. |
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| 9. |
- Larsson, Per, et al.
(författare)
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Atmospheric transport of persistent pollutants governs uptake by Holarctic biota
- 1990
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 24:10, s. 1599-1601
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Tidskriftsartikel (refereegranskat)abstract
- The atmospheric deposition of PCBs, DDT, and lindane,governed uptake in terrestrial biota in the Scandinavianpenninsula. Mammalian herbivores and predators as wellas predatory insects contained higher levels of pollutantsat locations where the fallout load was high than at stationswhere atmospheric deposition was lower, and the twovariables were significantly correlated.
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| 10. |
- Larsson, Per, et al.
(författare)
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Contaminated sediment as a source of PCBs in a river system
- 1990
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Ingår i: Canadian Journal of Fisheries and Aquatic Sciences. - : Canadian Science Publishing. - 0706-652X .- 1205-7533. ; 47:4, s. 746-754
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Tidskriftsartikel (refereegranskat)abstract
- The transport of PCBs (Aroclor 1242) in a river system in southern Sweden was governed by outflow from sediment in a 26-ha contaminated lake. Experiments in the lake revealed that 14 g PCBs/d escaped from the sediment, while sedimentation was 3 g PCB/d. Volatilization of PCBs from the lake surface was 0.02 g/d, which was considerably higher than the atmospheric fallout . The majority of the sediment-desorbed compounds (80%) remained at the river mouth, 60 km downstream, and entered the Baltic Sea. Desorption increased the ratio of tetrachlorobiphenyls to pentachlorobiphenyls in the water. Transport across the water/air interface was higher for trichlorobiphenyls, while atmospheric deposition was dominated by penta- and hexachlorobiphenyls. Therefore, the sediment of the lake acted as a source of PCBs entering the river system as well as the atmosphere.
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