Sökning: "Density-dependence"
Visar resultat 1 - 5 av 26 avhandlingar innehållade ordet Density-dependence.
1. Survival patterns and density-dependent processes in breeding mallards Anas platyrhynchos
Sammanfattning : Measuring and assessing vital rates such as births and deaths are prerequisites for understanding population dynamics. Vital rates may be affected by the density of individuals, even though the importance of density dependence on population dynamics has been debated for a long time. LÄS MER
2. Effects of size-dependent predation and competition on population and community dynamics
Sammanfattning : Most animals grow substantially during their lifetime and change in competitive ability, predatory capacity and their susceptibility to predation as they grow. This thesis addresses the implications of this on regulation and dynamics within populations as well as between population interactions. LÄS MER
3. Age-class interactions in Atlantic salmon and brown trout: Effects on habitat use and performance
Sammanfattning : This thesis investigates the underlying mechanisms and the density-regulatory effects of age-class interactions, using juvenile Atlantic salmon (Salmo salar L.) and brown trout (Salmo trutta L.) as study species. LÄS MER
4. The Preservation of Favoured Morphs in the Struggle Between Sexes
Sammanfattning : Sexual selection is particularly likely to promote population divergence, because sexual traits are expected to be subject to rapid evolutionary change. Identifying the relative roles of particular barriers to the amount of total reproductive isolation between populations or closely related species can provide important clues to the mechanisms of population divergence and speciation Phenotypic trait differences among populations are thought to reflect the interaction between the intensity of gene flow versus the strength of local selection and drift. LÄS MER
5. Ontogenetic scaling and the development of within-cohort size structure
Sammanfattning : It is increasingly recognized that individuals of the same species differ from each other and influence and respond to their environment in unique ways. This thesis deals with size variation among individuals that not only are of the same species but also of similar age. LÄS MER