Sökning: "André M. de Roos"

Hittade 3 avhandlingar innehållade orden André M. de Roos.

  1. 1. 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. 2. Ontogenetic bottlenecks : effects on intraguild predation systems and ecosystem efficiency

    Författare :Birte Reichstein; Lennart Persson; André M. De Roos; Priyanga Amarasekare; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; mixed interactions; cannibalism; life-history omnivory; ontogenetic niche shift; biomass overcompensation; biomass production; ontogenetic asymmetry; indirect effects; biology; biologi; zooekologi; Animal Ecology;

    Sammanfattning : Size-dependent differences between individuals in size-structured organisms have fundamental effect on population and community dynamics. Intraguild predation (IGP) is one specifically interesting constellation that often arises when two size-structured populations interact. LÄS MER

  4. 3. Alternative Stable States in Size-Structured Communities : Patterns, Processes, and Mechanisms

    Författare :Arne Schröder; Lennart Persson; André M. de Roos; Tim Benton; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; biomass overcompensation; Chaoborus; emergent Allee effect; Heterandria formosa; juvenile recruitment bottlenecks; ontogenetic niche shifts; Poecilia reticulata; Biology; Biologi;

    Sammanfattning : Alternative stable states have been, based on theoretical findings, predicted to be common in ecological systems. Empirical data from a number of laboratory and natural studies strongly suggest that alternative stable states also occur in real populations, communities and ecosystems. LÄS MER