Sökning: "pollen"
Visar resultat 1 - 5 av 244 avhandlingar innehållade ordet pollen.
1. Vegetation and climate during Weichselian ice free intervals in northern Sweden : Interpretations from fossil and modern pollen records
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. Sexual conflict and selection on pistil and pollen traits
Sammanfattning : The incidence of sexual selection in plants is today acknowledged, however, just as in animals, evolution and maintenance of mate choice is gravely underexplored. Moreover, the potential for sexual conflicts to occur in plants has only been assessed empirically to a very limited degree. LÄS MER
3. Pollen Competition as a Target for Sexual Selection in Plants
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
4. Ultrastructure and ontogeny of some angiosperm pollen
Sammanfattning : .... LÄS MER
5. Estimating source area of pollen and pollen productivity in the cultural landscapes of southern Sweden - developing a palynological tool for quantifying past plant cover
Sammanfattning : Fossil pollen records retrieved from peat and lake sediments have great potential for quantifying past plant cover. This thesis is a contribution to the development of a palynological interpretation tool for reconstructing past cultural landscapes in terms of plant abundance and distribution. LÄS MER