Sökning: "Plant-herbivore interactions"

Visar resultat 6 - 10 av 16 avhandlingar innehållade orden Plant-herbivore interactions.

  1. 6. Ecology and evolution in a host-parasitoid system : Host search, immune responses and parasitoid virulence

    Författare :Lisa Fors; Peter Hambäck; Wertheim Bregje; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Host-parasitoid interactions; Plant-herbivore interactions; Host search; Volatiles; Pheromones; Geographic variation; Cellular defence; Melanisation; Encapsulation; Asecodes; Galerucella; Plant Ecology; växtekologi;

    Sammanfattning : In host-parasitoid systems, there is a continuous coevolutionary arms race where each species imposes a strong selection pressure on the other. The host needs to develop defence strategies in order to escape parasitism and the parasitoid must evolve counter-defence strategies in order to overcome the host’s immune defence and successfully reproduce. LÄS MER

  3. 7. Ecological and Evolutionary Consequences of Herbivory in the Perennial Herb Lythrum salicaria

    Författare :Lina Lehndal; Jon Ågren; Peter Hambäck; Marc Johnson; Uppsala universitet; []
    Nyckelord :Disturbance gradient; Female reproductive success; Galerucella calmariensis; Galerucella pusilla; Herbivore removal; Latitudinal gradient; Local adaptation; Nanophyes marmoratus; Plant-herbivore interactions; Plant size; Resistance to herbivory; Tolerance to damage; Biology with specialization in Ecological Botany; Biologi med inriktning mot ekologisk botanik;

    Sammanfattning : In this thesis, I combined field, common-garden and greenhouse experiments to examine the ecological and evolutionary consequences of plant-herbivore interactions in the perennial herb Lythrum salicaria. More specifically I examined (1) whether resistance and tolerance to damage from herbivores vary with latitude and are positively related to the intensity of herbivory in natural populations, (2) whether effects of herbivory on plant fitness vary with latitude, (3) whether populations are locally adapted and whether herbivory influences the relative fitness of populations, and (4) whether the intensity and effects of insect herbivory on reproductive output vary locally along a disturbance gradient and are associated with differences in plant resistance. LÄS MER

  4. 8. Marine seaweed invasions : Impacts and biotic resistance in native ecosystems

    Författare :Josefin Sagerman; Sofia Wikström; Fransisco Arenas; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Plant invasion; exotic species; generalist herbivores; plant-herbivore interactions; enemy-release hypothesis; ecosystem function; marin ekotoxikologi; Marine Ecotoxicology;

    Sammanfattning : Marine seaweeds constitute one of the most productive plant systems known on Earth and a rich fauna including juvenile fish and crustaceans is dependent on the habitats they form. Human influence on marine costal ecosystems has resulted in large scale changes to the abundance and distribution of species, where species introductions constitute an obvious part. LÄS MER

  5. 9. Seaweed Invasions and Novel Chemical Defences

    Författare :Swantje Enge; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Biological invasions; enemy release; increased competitive ability; novel weapon; chemical defence; plant-herbivore interactions; competition; seaweeds; Bonnemaisonia hamifera;

    Sammanfattning : Biological invasions pose a risk to the biodiversity and the functioning of ecosystems in invaded areas. The reasons why some introduced species become dominant and widespread in their new environments is still largely an unsettled question. LÄS MER

  7. 10. Life History and Tolerance and Resistance against Herbivores in Natural Populations of Arabidopsis thaliana

    Författare :Reiko Akiyama; Jon Ågren; Arjen Biere; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Arabidopsis thaliana; life history evolution; flowering time; germination; phenology; plant-herbivore interactions; natural selection; tolerance to leaf damage; resistance to herbivory; Plutella xylostella; Mamestra brassicae; Biology with specialization in Ecological Botany; Biologi med inriktning mot ekologisk botanik;

    Sammanfattning : In this thesis, I combined observational studies with field and greenhouse experiments to examine selection on life history traits and variation in tolerance and resistance against herbivores in natural populations of the annual herb Arabidopsis thaliana in its native range. I investigated (1) phenotypic selection on flowering time and plant size, (2) the effects of timing of germination on plant fitness, (3) the effect of leaf damage on seed production, and (4) correlations between resistance against a specialist and a generalist insect herbivore. LÄS MER