Sökning: "Palaeobotany"

Visar resultat 1 - 5 av 7 avhandlingar innehållade ordet Palaeobotany.

  1. 1. Holocene vegetation dynamics and climate changes in the Torneträsk area, northern Sweden

    Författare :Lena Barnekow; Kvartärgeologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Paleobotanik; palynology; phylogeny; Palaeobotany; northern Sweden; Torneträsk; Abisko; lake-level; radiocarbon dating; forest history; Holocene; tree-line; climate; Vegetation; fylogeni; palynologi; Physical geography; geomorphology; pedology; cartography; climatology; Fysisk geografi; geomorfologi; marklära; kartografi; klimatologi;

    Sammanfattning : The aim of this study was to reconstruct the Holocene vegetation history and the climate changes in a subarctic area. The results are based on pollen and macrofossil records from six lakes in the Torneträsk area. The lakes are situated at altitudes between 370 and 999 m a.s. LÄS MER

  2. 2. Tree-limit ecotonal response to Holocene climate change in the Scandes Mountains of west-central Sweden

    Författare :Jonas Bergman; Kvartärgeologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; tree-limit ecotone; alpine vegetation; tephrochronology; peat humification; plant macrofossils; Palaeobotany; fylogeni; Paleobotanik; palynology; phylogeny; palynologi; Geologi; Geology; pedology; geomorphology; Physical geography; klimatologi; geomorfologi; climatology; Fysisk geografi; cartography; Holocene climate; palaeoecology; marklära; kartografi; pollen influx;

    Sammanfattning : The aim of this thesis was to reconstruct the Holocene vegetational and climatic development in the Sylarna-Storulvån area, western Jämtland, in the central Scandes Mountains. Temporal trends and fluctuations in the elevation and vegetational character of the tree-limit ecotone were studied mainly by means of pollen and plant macrofossil analysis of two lake sediment sequences (Lakes Stentjärn and Spåime), located above the present-day tree-limit. LÄS MER

  3. 3. The Late Holocene history of beech Fagus sylvatica and Norway spruce Picea abies at stand-scale in southern Sweden

    Författare :Leif Björkman; Kvartärgeologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; physical geography; Geology; south Sweden; Late Holocene; succession; disturbance; forest history; forest continuity; population dynamics; immigration; palaeoecology; pollen analysis; Fagus sylvatica; Picea abies; Geologi; fysisk geografi; Palaeobotany; phylogeny; palynology; Paleobotanik; fylogeni; palynologi;

    Sammanfattning : High resolution pollen analysis was carried out on five peat profiles from small forest hollows at four sites in southern Sweden. The general aim was to investigate the establishment of Fagus sylvatica and Picea abies at stand-scale. LÄS MER

  4. 4. The Ups and Downs of the Holocene: Exploring Relationships between Global CO2 and Climate Variability in the North Atlantic Region

    Författare :Catherine Jessen; Kvartärgeologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; marklära; geomorfologi; climatology; klimatologi; rapid climate change; Holocene climate; atmospheric CO2 concentrations; geochemical proxy indicators; Paleobotanik; palynology; Geology; palynologi; fylogeni; geomorphology; fysisk geografi; Geologi; physical geography; kartografi; pedology; cartography; phylogeny; Palaeobotany; stomatal frequency; lake sediments;

    Sammanfattning : This thesis aimed to examine the relationship between climate and atmospheric CO2 concentrations through rapid climate changes during the Holocene. Climate was reconstructed using high-resolution, radiocarbon dated, lake sediment geochemical proxies (magnetic susceptibility, loss-on-ignition, total carbon/nitrogen/sulphur determinations and biogenic silica), vegetational reconstruction (pollen analysis) and stomatal frequency based CO2 reconstructions. LÄS MER

  5. 5. Holocene climate and environmental dynamics on the Tristan da Cunha island group, South Atlantic

    Författare :Karl Ljung; Kvartärgeologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; palynologi; Geology; climate change; pollen analysis; Palaeobotany; phylogeny; palynology; Paleobotanik; fylogeni; vegetation change; gyttja; peat; Holocene; Quaternary; South Atlantic; Tristan da Cunha; physical geography; Geologi; fysisk geografi;

    Sammanfattning : It has been shown that the present interglacial has been climatically dynamic with both rapid and severe climatic fluctuations. The spatial and temporal differences of these changes are however not fully resolved. The aim of this thesis is to present a detail high resolution record of past climate changes from the central South Atlantic. LÄS MER