Sökning: "seed germination"

Visar resultat 1 - 5 av 36 avhandlingar innehållade orden seed germination.

  1. 1. The role of regeneration in plant niche differentiation and habitat specialization

    Författare :Dirk-Jan ten Brink; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; seed mass; seed size; drought; shade; seed germination; seed dormancy; seedling establishment; plant community ecology; assembly rules; habitat specialization; plant recruitment; Regeneration; niche differentiation; phylogenetic independent contrasts; plant traits; soil fertility; comparative ecology;

    Sammanfattning : To predict the effects of environmental change and nature management on the distribution of plant species, it is crucial to understand the mechanisms of plant niche differentiation and habitat specialization. The importance to habitat specialization of particular plant traits and requirement of the regenerative phase of the plants life has received scanty interest. LÄS MER

  2. 2. Seed dormancy and germination in an ecological context : comparative studies of annual weeds

    Författare :Laila Karlsson; Per Milberg; Ken Thompson; Linköpings universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; Asteraceae; Bidens; Compositae; deadnettle; Galinsoga; germination timing; Guizotia; evolution; Labiatae; Lamiaceae; Lamium; morphophysiological dormancy; Papaveraceae; Papaver; Parthenium; physiological dormancy; poppy; summer annual; Tagetes; Verbesina; winter annual; Biology; Biologi;

    Sammanfattning : Germination ecology studies, i.e. studies of interactions between characteristics of the seeds and environmental circumstances, provide understanding of spatial and temporal patterns of emergence of wild species, as weeds in the field. A large number of species have seed dormancy, i. LÄS MER

  3. 3. Selection during Early Life Stages and Local Adaptation in Arabidopsis thaliana

    Författare :Froukje M. Postma; Jon Ågren; Kathleen Donohue; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Dormancy cycling; Germination timing; Maternal effects; Natural variation; QTL mapping; Seed bank; Seed dormancy; Structural Equation Modeling; Biology with specialization in Ecological Botany; Biologi med inriktning mot ekologisk botanik;

    Sammanfattning : Organisms are often adapted to their local environment, but the role of early life stages in adaptive differentiation among populations remains poorly known. The aim of my thesis was to investigate the contribution of early life stages to the magnitude and genetic basis of local adaptation, and to identify the underlying adaptive traits. LÄS MER

  4. 4. On the Ecology and Evolution of seed and Bud Dormancy

    Författare :Patric Nilsson; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; bet-hedging; overcompensation; herbivory; plant compensatory growth; bud dormancy; endosperm; seed provisioning; Seed dormancy; parent-offspring conflicts; Ecology; Ekologi; Botany; Botanik;

    Sammanfattning : This thesis considers the ecological and evolutionary significance of seed and bud dormancy. First, I present theoretical support to the idea that seed dormancy may evolve as a strategy to reduce sib competition in temporally homogeneous environments. LÄS MER

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

    Författare :Stig-Olov Holm; Umeå universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; 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