Search for dissertations about: "Pollen interactions"

Showing result 1 - 5 of 20 swedish dissertations containing the words Pollen interactions.

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

   Author : Åsa Lankinen; Biologiska institutionen; []
   Keywords : 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;

   Abstract : 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. READ MORE

4. 2. Plant-animal interactions and seed output of two insectpollinated herbs

   Author : Anna R. Waites; Umeå universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; plant reproduction; pollen limitation; pollinator behaviour; heterostyly; seed predation; Lythrum salicaria; Pedicularis palustris; stigma receptivity; self-pollen; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi;

   Abstract : I combined comparative and experimental studies in the field and in the greenhouse to examine factors influencing reproductive success in two insect-pollinated herbs, the tristylous, selfincompatible perennial Lythrum salicaria and the self-compatible, biennial Pedicularis palustris. More specifically, I explored (i) the effects of plant population characteristics on the intensity and outcome of interactions with pollinators and seed predators, (ii) whether flower morphology affects duration of stigma receptivity, and (iii) whether damage-induced reduction in floral display reduces pollinator visitation and increases pollen limitation. READ MORE

5. 3. The Earth : climate and anthropogenic interactions in a long time perspective

   Author : Jörgen Olofsson; Institutionen för naturgeografi och ekosystemvetenskap; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; anthropogenic; climate change; land use; biodiversity; carbon; dynamic global vegetation model; Holocene; pre-industrial; pollen; bison;

   Abstract : The Earth is a highly complex and dynamic system. Life has shaped the entire planet and evolved in response to living conditions. Ecosystems are heavily affected by climate. Rapidly changing conditions imply considerable stress on several species and ecosystems, as well as to the most dominant species on the planet. READ MORE

6. 4. Plant-climate interactions over historical and geological time

   Author : Sharon A Cowling; Biologiska institutionen; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; atmospheric CO2; plant evolution; palaeoecology; plant-climate interactions; vegetation modelling; Plant ecology; Växtekologi;

   Abstract : Data-model comparisons are a useful approach to elucidating the relative influence of past climate change on vegetation dynamics over various spatial global, regional, stand) and temporal (historical, geological) scales. Comparisons between changes in tree species abundance reconstructed from pollen and simulated from a forest gap model, for example, indicate that based solely on climate change over the past 1500 years, southern Scandinavian forests should be co-dominated by Tilia and Fagus. READ MORE

7. 5. Selection on floral traits in Primula farinosa

   Author : Didrik Vanhoenacker; Johan Ehrlén; Jon Ågren; Arjen Biere; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; coevolution; correlational selection; Falseuncaria ruficiliana; geographic mosaic; hand pollination; Hermann Müller; interaction strength; plant-insect interactions; pollen limitation; selection strength; spatiotempora; Uta stansburiana; Biology; Biologi; Plant Ecology; växtekologi;

   Abstract : Flowers and inflorescences have evolved in relation to animals for at least 100 million years. Plants attract pollinators with large, conspicuous, bright-coloured or scented flowers. These display attributes, however, also attract herbivores. READ MORE