Search for dissertations about: "Density-dependence"

Showing result 1 - 5 of 26 swedish dissertations containing the word Density-dependence.

  2. 1. Survival patterns and density-dependent processes in breeding mallards Anas platyrhynchos

    Author : Gunnar Gunnarsson; Kjell Sjöberg; Johan Elmberg; Per Lundberg; Robert Clark; Högskolan Kristianstad; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; broods; dabbling ducks; density dependence; ducklings; experiments; models; mortality; nest predation; regulation; survival; Terrestrial ecology; Terrestrisk ekologi;

    Abstract : 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. READ MORE

  4. 2. Effects of size-dependent predation and competition on population and community dynamics

    Author : Karin Nilsson; Lennart Persson; Volker Rudolf; Umeå universitet; []
    Keywords : size-structure; cannibalism; resource competition; predation; emergent facilitation; population regulation; population dynamics; overcompensation; density-dependence; cycles; zooekologi; Animal Ecology;

    Abstract : 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. READ MORE

  5. 3. Age-class interactions in Atlantic salmon and brown trout: Effects on habitat use and performance

    Author : Rasmus Kaspersson; Göteborgs universitet; []
    Keywords : competition; inter-cohort; density-dependence; growth; habitat; Salmo trutta; Salmo salar; salmon; trout;

    Abstract : 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. READ MORE

  6. 4. The Preservation of Favoured Morphs in the Struggle Between Sexes

    Author : Thomas Gosden; Evolutionär ekologi; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Sexual Selection; Polymorphism; Density-dependence; Population divergence; Zygoptera; Sexual Conflict;

    Abstract : 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. READ MORE

  7. 5. Ontogenetic scaling and the development of within-cohort size structure

    Author : Magnus Huss; Lennart Persson; Pär Byström; David Post; Umeå universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; cannibalism; competition; density-dependence; resource feedbacks; hatching; growth; ontogenetic niche shifts; Perca fluviatilis; size variation; larval fish; Freshwater ecology; Limnisk ekologi; zooekologi; Animal Ecology;

    Abstract : 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. READ MORE