Sökning: "population limitation"
Visar resultat 1 - 5 av 102 avhandlingar innehållade orden population limitation.
1. Population differentiation in Lythrum salicaria along a latitudinal gradient
Sammanfattning : In this thesis, quantitative genetic approaches, common-garden experiments, and field studies were combined to examine patterns of population differentiation and the genetic architecture of characters of putative adaptive significance in the widely distributed perennial herb Lythrum salicaria. In this work, I (1) documented patterns of population differentiation in phenology, life-history, and morphology along latitudinal gradients at different geographical scales, (2) investigated the genetic architecture of phenology, flower morphology, and inflorescence size, and (3) combined estimates of phenotypic selection in the field with information on the genetic variance-covariance matrix (G) to examine potential constraints to adaptive evolution. LÄS MER
2. Single-cell population genetics and dispersal limitation of a bloom-forming microalga
Sammanfattning : Microalgal range expansions are increasing in frequency and magnitude worldwide mostly due to anthropogenic factors. However, they often remain unnoticed until mass development (algal blooms) occurs due to difficulties in detection when population densities are low. LÄS MER
3. Effects of farmland heterogeneity at multiple spatial and temporal scales on house sparrow (Passer domesticus) population ecology
Sammanfattning : Strong declines of European farmland birds in recent decades are assumed to be caused by decreased food availability resulting from agricultural intensification and concomitant loss of farmland heterogeneity. One of the species suffering particularly strong declines in NW European countries is the house sparrow. LÄS MER
4. Herbivory, pollen limitation and population dynamics in Lathyrus vernus
Sammanfattning : .... LÄS MER
5. Plant Population Dynamics and Biotic Interactions in two Forest Herbs
Sammanfattning : In Sweden today, deciduous woodlands are often restricted to small isolated remnants of what it once was. Managing practices have changed concerning both cattle grazing and logging. Thus, dispersal, habitat requirements and their importance for forest species distributions become a relevant issue. LÄS MER