Sökning: "seed predation"

Visar resultat 16 - 20 av 24 avhandlingar innehållade orden seed predation.

  1. 16. Seed dynamics and the ecological restoration of hill slopes of Kondoa Irangi, Central Tanzania

    Författare :Herbert V. M. Lyaruu; Ingvar Backéus; Jerry Skoglund; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ecology; anemochorous; Ekologi; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi; Ecological Botany; Ekologisk botanik;

    Sammanfattning : Improper agricultural practices such as bill slope cultivation, extensive clearing of vegetation using fire over a long period, and to some extent overgrazing have converted the once fertile hill slopes of Kondoa Irangi in central Tanzania into unproductive marginal land. It is 25 years now since reclamation measures were introduced to save the hills from further degradation, but the regeneration process, has been rather slow. LÄS MER

  3. 17. Recruitment and understorey herb dynamics in deciduous and mixed coniferous forest

    Författare :Heléne Fröborg; Mikael Ohlson; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ecological Botany; ekologisk botanik;

    Sammanfattning : The distribution and abundance of plant species is determined by the ability to disperse, recruit and persist in a suitable habitat. Plant-animal interactions influence recruitment by reducing seeds and seedlings through predation and herbivory. LÄS MER

  4. 18. Environmental heterogeneity, population dynamics and life-history differentiation in Primula farinosa

    Författare :Tove von Euler; Johan Ehrlén; Jon Ågren; Olav Skarpaas; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Plant Ecology; växtekologi;

    Sammanfattning : Allocation to reproduction is a key life-history trait. Optimal allocation to reproduction depends on environmental conditions because of their effects both on costs and benefits of reproduction and on patterns of growth, fecundity, and mortality. LÄS MER

  5. 19. Selection on floral traits in Primula farinosa

    Författare :Didrik Vanhoenacker; Johan Ehrlén; Jon Ågren; Arjen Biere; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; coevolution; correlational selection; Falseuncaria ruficiliana; geographic mosaic; hand pollination; Hermann Müller; interaction strength; plant-insect interactions; pollen limitation; selection strength; spatiotempora; Uta stansburiana; Biology; Biologi; Plant Ecology; växtekologi;

    Sammanfattning : Flowers and inflorescences have evolved in relation to animals for at least 100 million years. Plants attract pollinators with large, conspicuous, bright-coloured or scented flowers. These display attributes, however, also attract herbivores. LÄS MER

  7. 20. Temporal effects of organic farming on biodiversity and ecosystem services

    Författare :Dennis Jonason; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
    Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : Agricultural intensification has caused a dramatic decline of global biodiversity and associated ecosystem services. Organic farming has been shown to partially counteract agricultural intensification by applying environmentally friendly and resource efficient farming practices, but opportunities to improve in efficiency still remain. LÄS MER