Sökning: "interspecific differences"

Visar resultat 1 - 5 av 15 avhandlingar innehållade orden interspecific differences.

  1. 1. The effects of stage-specific differences in energetics on community structure

    Författare :Tim Schellekens; Andre de Roos; Tom Anderson; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; ontogenetic diet shift; stage-structured biomass model; food-dependence; growth; development; Earth sciences; Geovetenskap; NATURAL SCIENCES; NATURVETENSKAP; Earth Sciences with Specialization Environmental Analysis; geovetenskap med inriktning mot miljöanalys;

    Sammanfattning : When intraspecific individuals differ in resource intake, scramble competition occurs among inferior individuals growing food-dependently. Scramble can be released through predation mortality. As a consequence of this release, production rates in inferior individuals increase and biomass overcompensation in the subsequent life-stages may occur. LÄS MER

  3. 2. Interspecific Interactions between Native Brown Trout and Invasive Brook Trout: Insights into Behaviour and Morphology

    Författare :Magnus L. Wallerius; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Invasive species; Fish; Competition; Foraging; Management;

    Sammanfattning : The introduction of non-native species represents a global threat to ecosystems and biodiversity. In Europe, the introduction of the invasive brook trout (Salvelinus fontinalis) has led to species displacement and local extinction of native brown trout (Salmo trutta) populations. LÄS MER

  4. 3. Effects of Social Organisation on Spatial Genetic Structures in Formica Ants

    Författare :Niclas Gyllenstrand; Michael Bruford; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Biology; Formica ants; microsatellites; monogyny; mtDNA; polygyny; social insects; Biologi; Biology; Biologi; naturvårdsbiologi; Conservation Biology;

    Sammanfattning : The social organization of social insect colonies can be broadly defined as monogynous, single reproductive female or polygynous, several reproductive females. Monogynous organization is genetically simple while polygynous is more complex and the two social forms differ commonly in mating and dispersal behaviour as well as in colony foundation. LÄS MER

  5. 4. Reproductive patterns of birches (Betula spp.) in northern Sweden

    Författare :Stig-Olov Holm; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Reproduction; Betula; seed-quality; seed-set; pollination; pollen-limitation; pollen-competition; tree-line; environmental gradient; seed weight; seedling survival; Semudobia;

    Sammanfattning : The aim of this thesis was to study patterns of reproduction of Betula pendula and B. pubescens coll. along an altitudinal, coastal-inland, gradient in northern Sweden. The altitudinal variation was related to the distribution of the birch taxa along the gradient. LÄS MER

  7. 5. Circadian Rhythms in Moth Sex Pheromone Communication

    Författare :Germund von Wowern; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physiology of invertebrates; växtparasitologi; Entomologi; plant parasitology; Entomology; Ecology; Ekologi; locomotor activity; social synchronisation; PDH; corazonin; PBAN; pheromone response; sex phermone; Lepidoptera; Ryggradslösa djurs fysiologi; calling behaviour; circadian rhythm;

    Sammanfattning : Sex pheromone communication and related physiological processes are regulated by circadian clock mechanisms in many moth species. This thesis includes studies of circadian rhythms in sexually relevant behaviours and communication in the Egyptian cotton leafworm Spodoptera littoralis, the turnip moth Agrotis segetum, the Indian meal moth Plodia interpunctella and the Mediterranean flour moth Ephestia kuehniella. LÄS MER