Sökning: "environmental reconstructions"
Visar resultat 11 - 15 av 81 avhandlingar innehållade orden environmental reconstructions.
11. Diatoms as indicators of Holocene climate and environmental change in northern Sweden
Sammanfattning : The objective of the thesis was to explore the potential of diatoms (Bacillariophyceae) as indicators of Holocene climate and environmental change in northern Sweden (Abisko region, 68°21'N, 18°49'E). A modern surface-sediment calibration set including 100 lakes was developed and lake-water pH, sedimentary organic content (assessed by loss-on-ignition) and temperature were identified as most powerful environmental variables explaining the variance within the diatom assemblages. LÄS MER
12. Holocene Climate in Central and Southern Sweden : Quantitative Reconstructions from Fossil Data
Sammanfattning : In quantitative palaeoecology modern species-environmental relationships can be statistically modelled, and recent development has made the calibration models more statistically robust. These models are used to transform fossil assemblages to quantitative estimates of past environmental conditions. LÄS MER
13. Disentangling production and climate signals from high-resolution Beryllium records: implications for solar and geomagnetic reconstructions
Sammanfattning : The sun is the most important energy source for the Earth’s climate system, however, influences of solar variations on climate are not fully understood. Studying past solar activity can improve our understanding of what role the sun plays in Earth’s climate. LÄS MER
14. Tracing marine hypoxic conditions during warm periods using a microanalytical approach
Sammanfattning : Deoxygenation, i.e. loss of oxygen from the oceans, often considerably influences the aquatic organisms and the wholeecosystem and changes biogeochemical cycles. It results in increasing bottom areas of hypoxia (. LÄS MER
15. Alpine lake sediment archives and catchment geomorphology : causal relationships and implications for paleoenvironmental reconstructions
Sammanfattning : Lake sediments are frequently used as archives of climate and environmental change. Minerogenic sediment variability in alpine lakes is often used to reconstruct past glacier and slope process activity. Alpine lake sediments can however have many different origins, which may induce errors in paleoenvironmental reconstructions. LÄS MER