Thesis (M.Sc.)--Memorial University of Newfoundland, 2002. / Bibliography: leaves 144-155.

Thesis (M.Sc.) -- Memorial University of Newfoundland. / Typescript. Bibliography: leaves 106-115. Also available online.

Universiẗat, Diss., 2004--München.

<p>Diss. (sammanfattning) Umeå : Univ., härtill 6 uppsatser.</p> / digitalisering@umu

<p>High-latitude watersheds have been regarded as a carbon sink with soil carbon accumulating at low temperature. This sink is now believed to turn into a source, acting as positive feedback to climate warming. However, thawing permafrost soils would allow more water to percolate down to deeper soil layers where some of the carbon could be “consumed” in weathering and exported as bicarbonate to the sea. Using a hydrological mixing model showed that this could counterbalance the predicted positive feedback resulting from thawing soils.</p><p>Vegetation-covered riparian zones in headwater areas appear to have a significant role for the dissolved constituent fluxes. Higher concentrations of weathering products are found in taiga and tundra rivers with larger areas of forest and peat cover in the watershed. These landscape elements can thus be regarded as “hot spots” of river loading with dissolved constituents.</p><p>Comparing a regulated and an unregulated river tested the hypothesis that damming leads to a depletion of major elements also in oligotrophic river systems as a consequence of changes in landscape elements. A loss of upper soils and vegetation through inundation prevents the contact of surface waters with vegetated soil, and consequently reduces weathering fluxes. The hypothesis that the lower fluxes of dissolved silica (DSi) in the regulated river could also be explained by biological uptake was then tested using a model, and budget calculations indicate a significant reduction as a result of regulation. About 10% of this reduction can be attributed to the flooding of the fluvial corridor and the rest to diatom blooms in the reservoirs. A more detailed study of landscape elements for the headwaters of the river Luleälven showed that only 3% of the surface area has been inundated by reservoirs but ca. 37% of the deciduous forest. Such a significant loss of hot spots may indeed explain the observed lower DSi fluxes in the regulated watersheds of northern Sweden.</p>

<p>Natura 2000 is part of the European Union: s framework to protect and preserve biological diversity. Natura 2000- areas are by the goverment appointed to areas of national interest for preserving nature. Also wind power stations are appointed as of national interest and the reason for this is the goverments goal to get energy from reneweble energysources. This essay describes when both these intrests conflict eachother when it comes to building wind power stations <em>within</em> Natura 2000- areas. The main focus of this essay is a casestudy of two cases from two different counties, Dalarna- and Norrbotten county, where applications have been made to build wind power stations within existing Natura 2000- ares, both cases have reached the court dealing with enviromental issues. In Dalarna county the court dealing with enviromental issues said no to the application and in Norrbotten the court said yes but in both cases simular factors seem to have been determining the outcome. For instance seem the Natura 2000 protection to be of minor consideration and rather <em>what kind</em> of habitats and biotopes that could be damaged in case of putting up a wind power station park and <em>how</em> these habitats and biotopes would be affected seems to have been the main focus. In Dalarna county the area is consisting to onehundered percent of the priority biotope western taiga and in Norrbotten the area holds different types of biotopes of which some are counted as prioritied biotopes. The amount of energy produced have also been in focus when judgement have been made in the two cases. The fact that both wind power stations and Natura 2000 are of national interest seem to have been of no consideration and the conflict between these two interests does not seem to have been in focus in the two cases.</p>

Thesis (Ph.D.)--Memorial University of Newfoundland, 2005. / Includes bibliographical references.

High-latitude watersheds have been regarded as a carbon sink with soil carbon accumulating at low temperature. This sink is now believed to turn into a source, acting as positive feedback to climate warming. However, thawing permafrost soils would allow more water to percolate down to deeper soil layers where some of the carbon could be “consumed” in weathering and exported as bicarbonate to the sea. Using a hydrological mixing model showed that this could counterbalance the predicted positive feedback resulting from thawing soils. Vegetation-covered riparian zones in headwater areas appear to have a significant role for the dissolved constituent fluxes. Higher concentrations of weathering products are found in taiga and tundra rivers with larger areas of forest and peat cover in the watershed. These landscape elements can thus be regarded as “hot spots” of river loading with dissolved constituents. Comparing a regulated and an unregulated river tested the hypothesis that damming leads to a depletion of major elements also in oligotrophic river systems as a consequence of changes in landscape elements. A loss of upper soils and vegetation through inundation prevents the contact of surface waters with vegetated soil, and consequently reduces weathering fluxes. The hypothesis that the lower fluxes of dissolved silica (DSi) in the regulated river could also be explained by biological uptake was then tested using a model, and budget calculations indicate a significant reduction as a result of regulation. About 10% of this reduction can be attributed to the flooding of the fluvial corridor and the rest to diatom blooms in the reservoirs. A more detailed study of landscape elements for the headwaters of the river Luleälven showed that only 3% of the surface area has been inundated by reservoirs but ca. 37% of the deciduous forest. Such a significant loss of hot spots may indeed explain the observed lower DSi fluxes in the regulated watersheds of northern Sweden.

Natura 2000 is part of the European Union: s framework to protect and preserve biological diversity. Natura 2000- areas are by the goverment appointed to areas of national interest for preserving nature. Also wind power stations are appointed as of national interest and the reason for this is the goverments goal to get energy from reneweble energysources. This essay describes when both these intrests conflict eachother when it comes to building wind power stations within Natura 2000- areas. The main focus of this essay is a casestudy of two cases from two different counties, Dalarna- and Norrbotten county, where applications have been made to build wind power stations within existing Natura 2000- ares, both cases have reached the court dealing with enviromental issues. In Dalarna county the court dealing with enviromental issues said no to the application and in Norrbotten the court said yes but in both cases simular factors seem to have been determining the outcome. For instance seem the Natura 2000 protection to be of minor consideration and rather what kind of habitats and biotopes that could be damaged in case of putting up a wind power station park and how these habitats and biotopes would be affected seems to have been the main focus. In Dalarna county the area is consisting to onehundered percent of the priority biotope western taiga and in Norrbotten the area holds different types of biotopes of which some are counted as prioritied biotopes. The amount of energy produced have also been in focus when judgement have been made in the two cases. The fact that both wind power stations and Natura 2000 are of national interest seem to have been of no consideration and the conflict between these two interests does not seem to have been in focus in the two cases.

The cover of the ericaceous shrub Kalmia angustifolia L. (sheep's laurel or lamb's kill) expands rapidly on many clear-cut sites through central Newfoundland and northern Quebec. Previous laboratory and greenhouse studies on the effect of Kalmia on black spruce (Picea mariana (Mill.) B.S.P.) germinants and seedlings have demonstrated that extracts of Kalmia leaves and soil can reduce the germination rate and early root and shoot growth of black spruce. Observations in the field have suggested that Kalmia leaves and soil can reduce the germination rate and early rot and shoot growth of black spruce. Observations in the field have suggested that Kalmia reduces the growth of planted spruce seedlings. The experiments presented in this thesis were designed to determine the importance of Kalmia in controlling spruce growth and nutrition, and to document how the importance of Kalmia varies from site to site. Spruce seedlings growing in close proximity to Kalmia were found to be shorter and had lower foliar concentrations of N and P, and the roots of these seedlings had lower rates of mycorrhization and a more frequent occurrence of the pseudo-mycorrhizal/pathogenic fungus Phialocephala dimorphospora Kendrick. Results suggest that Kalmia impedes the N nutrition of spruce seedlings through the reduction of N mineralization rates and N availability. The results of path analysis further suggest that Kalmia had a direct effect on both spruce foliar N concentration and spruce growth. These findings do not demonstrate, though they are consistent with the suggestion, that Kalmia can affect spruce through allelopathic processes. Although we could not demonstrate that the reduction of rates of mycorrhization were due to indirect effects of Kalmia on spruce nutrition, we demonstrated that improving spruce nutrition in close proximity to Kalmia increased, though not significantly, the occurrence of mycorrhizae on spruce roots. Mycorrhizal symbiosis was shown to play a key role in t