Sökning: "paleolimnology"

Visar resultat 1 - 5 av 8 avhandlingar innehållade ordet paleolimnology.

1. 1. Combining limnology and paleolimnology : a refined understanding of environmental sediment signal formation in a varved lake

   Författare :Dominique Béatrice Maier; Christian Bigler; Sebastian Diehl; Jasmine E. Saros; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; varved lake sediments; diatom sediment signal formation; sequential sediment trap; seasonal process timing; ice thinning; varve compaction; climate impact; catchment properties; Earth Sciences with Specialization Environmental Analysis; geovetenskap med inriktning mot miljöanalys;

   Sammanfattning : Paleoclimatic archives, such as lake sediments, extend our understanding of terrestrial and aquatic ecosystem dynamics in relation to climate variability beyond the period covered by instrumental data. In this context, annually laminated (i.e. LÄS MER

3. 2. A paleolimnological perspective on liming – implications for defining reference conditions in Swedish lakes

   Författare :Matilda Norberg; Ingemar Renberg; Helen Bennion; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Acidification; Liming; European Water Framework Directive; Reference condition; Diatoms; Paleolimnology; Monitoring; Lake sediments; Earth sciences; Geovetenskap; Earth Sciences with Specialization Environmental Analysis; geovetenskap med inriktning mot miljöanalys;

   Sammanfattning : Using paleolimnological techniques, I have studied surface-water acidification and the effects of liming in Swedish lakes on a decadal to millennial time-scale. The overall objective was to contribute to the discussion on the fulfilment of goals within the Swedish liming program. LÄS MER

4. 3. Diatoms as indicators of Holocene climate and environmental change in northern Sweden

   Författare :Christian Bigler; Ingemar Renberg; Roland Hall; N. John Anderson; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physical geography and sedimentology; diatoms; Holocene; paleolimnology; climate change; lake sediments; transfer functions; quantitative environmental reconstructions; northern Sweden; Abisko; Naturgeografi och sedimentologi; Physical geography; Naturgeografi; naturgeografi; Physical Geography;

   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

5. 4. Linking lake variability, climate, and human activity in Basotu, Tanzania

   Författare :Lindsey Higgins; Lars-Ove Westerberg; Jan Risberg; Sarah Davies; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Tanzania; crater lake; climate change; land-use change; water resources; environmental variability; diatoms; paleolimnology; chronology; Physical Geography; naturgeografi;

   Sammanfattning : Paleoenvironmental investigations establish important baseline knowledge of the natural variability of lake systems, to better understand human impacts on the landscape, and the effects of climate change on water resources. By combining long-term environmental history with investigations into modern land use patterns and climatological events, a wider perspective can be reached that has practical applications in water governance. LÄS MER

7. 5. Infrared spectroscopy as a tool to reconstruct past lake-ecosystem changes : Method development and application in lake-sediment studies

   Författare :Carsten Meyer-Jacob; Richard Bindler; Hendrik Vogel; Jan Karlsson; John F. Boyle; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Fourier transform infrared spectroscopy; visible-near infrared spectroscopy; PLS regression; biogenic silica; climate change; carbon cycling; lake-water quality; geochemistry; paleolimnology; Holocene; Lake El’gygytgyn; Torneträsk;

   Sammanfattning : Natural archives such as lake sediments allow us to assess contemporary ecosystem responses to climate and environmental changes in a long-term context beyond the few decades to at most few centuries covered by monitoring or historical data. To achieve a comprehensive view of the changes preserved in sediment records, multi-proxy studies – ideally in high resolution – are necessary. LÄS MER