Sökning: "Large herbivores"

Visar resultat 6 - 10 av 46 avhandlingar innehållade orden Large herbivores.

1. 6. Busted by the bite : Molecular evidence of cryptic foraging behaviors in large herbivores

   Författare :Ruth Nichols; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : Large herbivores are charismatic species known to engineer ecosystems through a variety of effects. Conflicts can sometimes arise when these effects are undesirable. However, without detailed knowledge on herbivore selectivity for landscapes, patches and plants, these positive and negative effects remain difficult to predict. LÄS MER

3. 7. 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

4. 8. The Effect of Snow on Plants and Their Interactions with Herbivores

   Författare :Mikaela Torp; Johan Olofsson; Christa Mulder; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Snow; arctic ecosystem; plant-herbivore interactions; phenology; nitrogen; phenolics; experimental manipulation; natural gradient; inter-annual variability; Biology; Biologi;

   Sammanfattning : The ongoing climate changes are predicted to accelerate fast in arctic regions with increases in both temperatures and precipitation. Although the duration of snow cover is generally expected to decrease in the future, snow depth may paradoxically increase in those areas where a large amount of the elevated precipitation will fall as snow. LÄS MER

5. 9. Effects of facilitation and competition on oak seedlings : using shrubs as nurse-plants to facilitate growth and reduce browsing from large herbivores

   Författare :Anna M Jensen; Magnus Löf; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
   Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES;

   Sammanfattning : Plant–plant interactions have been indicated as a potential means to facilitate oak seedling establishment and reduce herbivory when restoring oak forests. The aim of this thesis was to investigate mechanisms and outcomes of competitive and indirectly facilitative interactions between oak (Quercus robur and Q. 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