Search for dissertations about: "Evolution of flower size"

Showing result 1 - 5 of 7 swedish dissertations containing the words Evolution of flower size.

2. 1. Evolution of Plants : a mathematical perspective

   Author : Magnus Lindh; Åke Brännström; Jacob Johansson; Mats G Larson; Lennart Persson; Claus Rüffler; Umeå universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Evolution; plants; mathematics; optimization; optimal control; adaptive dynamics; flowering; seasons; tree crown; drought; taproot; trade-off; strategy; trait; ESS; NPP; LAI; Red Queen; Mathematics; matematik;

   Abstract : The Earth harbors around 300 000 plant species. The rich and complex environment provided by plants is considered a key factor for the extraordinary diversity of the terrestrial fauna by, for example, providing food and shelter. READ MORE

4. 2. Evolution of Spur Length in a Moth-pollinated Orchid

   Author : Elin Boberg; Jon Ågren; W. Scott Armbruster; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Platanthera bifolia; floral evolution; natural selection; pollination; spur length; population differentiation; divergent selection; disruptive selection; reproductive isolation; Biology; Biologi; Ecological Botany; Ekologisk botanik;

   Abstract : There is considerable evidence that pollinator shifts can explain many differences in flower morphology between closely related plant species, but the extent to which pollinator shifts can explain the maintenance of among-population variation in floral traits within species is poorly known. In this thesis, I combined comparative and experimental approaches to examine the evolution of floral traits in the moth-pollinated orchid Platanthera bifolia. READ MORE

5. 3. To Bee or Not to Be : Critical Floral Resources of Wild-Bees

   Author : Magnus Larsson; Anders L Nilsson; Jon Ågren; Björn Cederberg; James H Cane; Uppsala universitet; []
   Keywords : Ecology; Andrena hattorfiana; Andrena marginata; Andrenidae; Knautia arvensis; limitation; oligolecty; pollen; pollination; solitary bee; specialist bee; Succisa pratensis; Ekologi;

   Abstract : In recent decades, the development of strategies to prevent or slow the loss of biodiversity has become an important task for ecologists. In most terrestrial ecosystems wild-bees play a key role as pollinators of herbs, shrubs and trees. The scope of this thesis was to study 1) pollinator effectiveness of specialist bees vs. READ MORE

6. 4. The Ecology of Floral Signals in Penstemon digitalis

   Author : Rosalie Burdon; Amy L. Parachnowitsch; James Thomson; Uppsala universitet; []
   Keywords : Antimicrobial; Bombus impatiens learning; indirect signal; multimodal; nectar; protandry; signal-reward association; Volatile Organic Compounds VOCs ; Biology with specialization in Ecological Botany; Biologi med inriktning mot ekologisk botanik;

   Abstract : In this thesis, I combined field observations and lab experiments to explore the ecological significance of floral signals in a North American wildflower, Penstemon digitalis. More specifically, to determine the potential mechanisms driving selection on floral scent, I studied how scent mediates interactions with pollinators and antagonists by (1) observing spatiotemporal variation in scent emission (2), floral volatile ability to suppress microbes (3) the honest advertisement of nectar, and (4) if scent could aid pollinator learning by reinforcing visual signals. READ MORE

7. 5. Pollination processes - maternal and offspring performance

   Author : Kristina Holmén Bränn; Kari Lehtilä; Pia Mutikainen; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Pollination; Sinapis arvensis; Brassica napus; Raphanus raphanistrum; Succisa pratensis; Evolution of flower size; Maternal plant responses; Resource allocation; Reproductive success; Terrestrial ecology; Terrestisk ekologi; Plant Ecology; växtekologi;

   Abstract : Pollination is one of the most important factors determining the reproductive success of plants. This thesis examines processes associated to varying pollination, with focus on plant responses. The first aim was to examine the possibility and constraints for short-term evolution of flower size in Raphanus raphanistrum. READ MORE