Sökning: "pollen analysis"

Visar resultat 1 - 5 av 59 avhandlingar innehållade orden pollen analysis.

  1. 1. Vegetation and climate during Weichselian ice free intervals in northern Sweden : Interpretations from fossil and modern pollen records

    Författare :Martina Hättestrand; Ann-Marie Robertsson; Donatella Magri; Stockholms universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Weichselian; interstadial; stadial; glacial history; northern Sweden; Tärendö; Riipiharju; Rissejauratj; Veiki moraine; pollen analysis; pollen deposition; pollen trap; PAR; Quaternary geology; Kvartärgeologi;

    Sammanfattning : In this thesis the Weichselian history of northern Sweden is investigated, with emphasis on vegetation and climate during ice-free intervals. The main method used has been pollen analysis of sediments from pre-Late Weichselian landforms. To interpret fossil pollen assemblages, comparisons with modern pollen spectra were made. LÄS MER

  2. 2. Pollen Competition as a Target for Sexual Selection in Plants

    Författare :Åsa Lankinen; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Sexual selection; Pollen tube growth rate; Pollen selection models; Pollen interactions; Pollen competition; Plants; Phenotypic plasticity; Non-random mating; Genotype by environment interactions; Mate choice; Viola tricolor.; Plant ecology; Växtekologi;

    Sammanfattning : According to the theory of sexual selection, traits can evolve because they confer a mating advantage in competition with members from the same sex. In animals, sexual selection is considered as an important evolutionary force. In this thesis I have investigated the potential for sexual selection in plants. LÄS MER

  3. 3. Vegetation history, human impact and palaeogeography of West Estonia : Pollen analytical studies of lake and bog sediments

    Författare :Siim Veski; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; Earth sciences; Vegetation history; human impact; palaeogeography; shoreline displacement; The Baltic Sea; the Yoldia Sea; the Ancylus Lake; the Litorina Sea; pollen analysis; macro fossil analysis; bog and lake sediments; radiocarbon dating; Holocene; Estonia; Geovetenskap; Earth sciences; Geovetenskap; Earth Sciences with Specialization Environmental Analysis; geovetenskap med inriktning mot miljöanalys;

    Sammanfattning : The history of Holocene vegetation in western Estonia and the West Estonian Archipelago is described. Early Holocene sea level changes in the area are reconstructed, and human impact on the vegetation during the Late Holocene is discussed West Estonia was divided into five study areas (Rummu-Maardu, Mustjärve, Velise-Kiilaspere, Tôstamaa Peninsula, and northern Saaremaa in the West Estonian Archipelago, from north to south). LÄS MER

  4. 4. Holocene Environmental Change of Southern Öland, Sweden

    Författare :Kerstin Alm Kübler; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; Earth sciences; Pollen analysis; Öland; Sweden; heath vegetation; landscape history; Fagus; beach ridges; numerical analysis; Geovetenskap; Earth sciences; Geovetenskap; Quarternary Geology; kvartärgeologi;

    Sammanfattning : This thesis describes Holocene environmental change in Ottenby, southern Öland,Sweden. Analyses of pollen sequences collected distally in the Littorina ridge and in fentroughs between lower laying beach ridges show the vegetation history during twoperiods, the first around 8000 BP and the second from 0/500 AD to about present time. LÄS MER

  5. 5. Late Quaternary Biostratigraphy of Sediments of the Southeastern Baltic Sea

    Författare :Daiva Üsaityté; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; Earth sciences; SE Baltic Sea; pollen analysis; Late Quaternary; numerical zonation; principal components analysis; Geovetenskap; Earth sciences; Geovetenskap; Quarternary Geology; kvartärgeologi;

    Sammanfattning : This thesis presents Late Quaternary biostratigraphy in the SE Baltic Sea, based on palynological data from fifteen sediment cores. An objective subdivision of the cores has been achieved by numerical zonation. Ordination has revealed a succession of pollen spectra that can be used for biostratigraphic correlation across the region. LÄS MER