Sökning: "size structured populations"

Visar resultat 6 - 10 av 20 avhandlingar innehållade orden size structured populations.

  1. 6. The development of resource polymorphism – Effects of diet, predation risk and population dynamical feedbacks

    Författare :Jens Andersson; Lennart Persson; André M. De Roos; Umeå universitet; []
    Nyckelord :body shape; diet; geometric morphometrics; phenotypic plasticity; population dynamics; predation risk; resource polymorphism; size structured populations;

    Sammanfattning : This thesis deals with the evolution of individuals within a species adapted to utilize specific resources, i.e. resource polymorphism. Although a well-known phenomenon, the understanding of the mechanisms behind is not complete. LÄS MER

  3. 7. Effects of size-dependent predation and competition on population and community dynamics

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

    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

  4. 8. Permanence of age-structured populations in a spatio-temporal variable environment

    Författare :Sonja Radosavljevic; Vladimir Kozlov; Uno Wennergren; Bengt-Ove Turesson; Michael Chipot; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : It is widely recognized that various biotic and abiotic factors cause changes in the size of a population and its age distribution. Population structure, intra-specific competition, temporal variability and spatial heterogeneity are identified as the most important factors that, alone or in combination, influence population dynamics. LÄS MER

  5. 9. Temperature- and body size scaling: effects on individuals, populations and food webs

    Författare :Max Lindmark; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : Climate warming impacts organisms directly through changes in their physiology. Empirical evidence suggest warming has already led to changes in growth, body size, population and community size-structure of natural populations. However, it is difficult to understand the underlying mechanisms from observational data alone. LÄS MER

  7. 10. Stochastic epidemics on random networks

    Författare :Abid Ali Lashari; Pieter Trapman; Filip Lindskog; Peter Neal; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Branching process; Configuration model; Random graph; Epidemic process; Final size; Threshold behaviour; Duration of an epidemic; Vaccination; Mathematical Statistics; matematisk statistik;

    Sammanfattning : This thesis considers stochastic epidemic models for the spread of epidemics in structured populations. The asymptotic behaviour of the models is analysed by using branching process approximations. The thesis contains four manuscripts. LÄS MER