Sökning: "species composition"
Visar resultat 1 - 5 av 597 avhandlingar innehållade orden species composition.
Sammanfattning : Models of climate change predict that temperature will increase during the 21th century and the largest warming will take place at high northern latitudes. In addition to warming, predictions for northern Europe include increased annual precipitation and a higher proportion of the precipitation during winter falling as rain instead of snow. LÄS MER
Sammanfattning : Many of the earth’s ecosystems are experiencing large species losses due to human impacts such as habitat destruction and fragmentation, climate change, species invasions, pollution, and overfishing. Due to the complex interactions between species in food webs the extinction of one species could lead to a cascade of further extinctions and hence cause dramatic changes in species composition and ecosystem processes. LÄS MER
3. Bacterial Activity and Community Composition in the Rhizosphere. Influence of plant species, root age, nitrogen addition and mycorrhizal status
Sammanfattning : Microbial activity in soil is generally assumed to be limited by carbon availability. The soil closest to roots, the rhizosphere, is therefore a zone of high microbial activity due to carbon containing substances released by the root. In this work short-term effects in the rhizosphere have been the subject of investigation. LÄS MER
Sammanfattning : Seabirds concentrate large amounts of marine nutrients on their nesting islands. This nutrient input can have large consequences for island food webs and community structure. The high nutrient load may also cause runoff into surrounding waters and affect marine communities. LÄS MER
5. Possibilities to Utilize Species from the Mozambican Forest Biomass for the Production of Essential Oils : Study of Eucalyptus and Pinus Species and Application of Citronellal as Raw Material for Flavour Chemistry
Sammanfattning : This thesis deals partly with the isolation and chemicalanalysis of essential oils from selected Eucalyptus and Pinusspecies grown in Mozambique, and partly with the synthesis ofmore valuable compounds from citronellal isolated fromEucalyptus citriodora Hook oil.More than 60 constituents in the volatile oils wereidentified by gas chromatography and gas chromatography-massspectrometry by comparison with authentic substances andliterature data. LÄS MER