Sökning: "Fennoscandia."
Visar resultat 1 - 5 av 72 avhandlingar innehållade ordet Fennoscandia..
1. Late Holocene spatiotemporal hydroclimatic variability over Fennoscandia inferred from tree-rings
Sammanfattning : There is a broad scientific consensus that the global climate is changing, and that human activity is a significant factor contributing to the change. The response of the hydrological cycle to the warming is far reaching, including increases in the intensification and frequency of extreme hydroclimatological events. LÄS MER
2. Soil Organic Matter Dynamics and Methane Fluxes at the Forest – Tundra Ecotone in Fennoscandia
Sammanfattning : This thesis presents results from several studies that have focused on the carbon and nutrient dynamics in soils at the forest – tundra ecotone in Fennoscandia. The main objectives of the study were: (i) to investigate the links between the physical environment, above-ground vegetation communities, soil carbon storage, nutrient status and the chemical composition of the soil organic matter (SOM), and (ii) to quantify trace gas fluxes (methane and carbon dioxide) between mesic soils and the atmosphere. LÄS MER
3. Holocene climate and atmospheric circulation changes in northern Fennoscandia : Interpretations from lacustrine oxygen isotope records
Sammanfattning : This thesis investigates how variations in the oxygen isotopic composition of lake waters in northern Fennoscandia are recorded in lake sediment archives, especially diatoms, and how these variations can be used to infer past changes in climate and atmospheric circulation. Results from analyses of the oxygen isotopic composition of lake water samples (δ18Olakew) collected between 2001 and 2006 show that δ18O of northern Fennoscandian lakes is mainly controlled by the isotopic composition of the precipitation (δ18Op). LÄS MER
4. A green future with thawing permafrost mires? : a study of climate-vegetation interactions in European subarctic peatlands
Sammanfattning : Climate projections indicate that Arctic and sub-Arctic regions are facing a significant change in climate during the 21st century. With warmer temperatures precipitation is also expected to increase, and in particular winter precipitation. LÄS MER
5. Testing palaeomagnetic and 14C based geochronological methods in the Baltic Sea
Sammanfattning : The Baltic Sea is a continental shelf sea that is influenced by both river runoff and marine water. The two water masses are vertically stratified in the Baltic Sea, resulting in a positive, estuarine circulation system, which has undergone changes in the past due to isostatic uplift of the Baltic basin. LÄS MER