Sökning: "herbivore pressure"
Visar resultat 1 - 5 av 9 avhandlingar innehållade orden herbivore pressure.
1. Ecology and evolution of tolerance in two cruciferous species
Sammanfattning : Tolerance to herbivory is the ability of plants to maintain fitness in spite of damage. The goal of this thesis is to investigate the genetic variation and expression of tolerance within species, determine whether and in what conditions tolerance has negative side-effects, and how tolerance is affected by different ecological factors. LÄS MER
2. Plant-soil-herbivore interactions in a high Arctic wetland - Feedbacks to the carbon cycle
Sammanfattning : Arctic ecosystems hold massive amounts of the global carbon in their soils and are of great importance for the global terrestrial exchange of greenhouse gases to the atmosphere. The arctic region has in general been acting as a C sink for the past 10000 years, however with climate change the C balance in some areas is shifting towards becoming a C source. LÄS MER
3. Ecology and evolution in a host-parasitoid system : Host search, immune responses and parasitoid virulence
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
4. Marine seaweed invasions : Impacts and biotic resistance in native ecosystems
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. The role of herbivores in mediating responses of tundra ecosystems to climate change
Sammanfattning : The Arctic areas are warming more rapidly than other parts of the world. Increasing temperatures are predicted to result in shrubification, higher productivity, declining species diversity and new species invasions to the tundra. LÄS MER