Sökning: "flower production"
Visar resultat 1 - 5 av 17 avhandlingar innehållade orden flower production.
1. Pheromone production in the butterfly Pieris napi L
Sammanfattning : Aphrodisiac and anti-aphrodisiac pheromone production and composition in the green-veined white butterfly Pieris napi L. were investigated.Aphrodisiac pheromone biosynthesis had different time constraints in butterflies from the diapausing and directly developing generations. LÄS MER
2. Population Differentiation in Solidago virgaurea along Altitudinal Gradients
Sammanfattning : Altitudinal gradients offer attractive opportunities for studies of population differentiation in response to environmental heterogeneity. In this thesis, I examined population differentiation along altitudinal gradients by combining common-garden experiments with field studies and experiments in alpine, subalpine and boreal populations of the perennial herb Solidago virgaurea. LÄS MER
3. To Bee or Not to Be : Critical Floral Resources of Wild-Bees
Sammanfattning : 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. LÄS MER
4. Plant-seed predator interactions – ecological and evolutionary aspects
Sammanfattning : Plant-animal interactions are affected by both abundance and distribution of interacting species and the community context in which they occur. However, the relative importance of these factors is poorly known. LÄS MER
5. The ecological significance of cleistogamy
Sammanfattning : Various aspects of cleistogamy, a reproductive system combining selfing in closed (cleistogamous) flowers and potential outcrossing in open (chasmogamous) flowers, were investigated in four perennial species. The main purpose was to shed some light on the adaptive value of having a dual reproductive strategy, and to test some hypotheses on the maintenance of xenogamy. LÄS MER