Search for dissertations about: "Perennial"
Showing result 1 - 5 of 106 swedish dissertations containing the word Perennial.
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1. Population dynamics of the perennial weed species Sonchus arvensis L
Abstract : Sonchus arvensis L. is a perennial weed that is widely prevalent in annual crops in northern Europe and can cause substantial yield losses. The abundance of S. arvensis has increased recently, primarily due to expansion of organic farming and increased use of reduced tillage. READ MORE
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2. IgE sensitization against food allergens : Natural history, relation to airway inflammation and asthma
Abstract : Background: According to recent studies in children, IgE sensitization not only against perennial allergens, but also against food allergens, is related to asthma risk and increased airway inflammation. During the last decade, a new technique for IgE determination based on allergen components has become available, but its use in epidemiological studies has been limited. READ MORE
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3. Ecological and Evolutionary Consequences of Herbivory in the Perennial Herb Lythrum salicaria
Abstract : 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. READ MORE
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4. Population dynamics of a perennial herb (Plantago maritima L.) along a distributional gradient : a demographical study
Abstract : In order to explain density distribution and provide the basis for further research on life history phenomena, the demography of Plantago maritima is described along a distributional gradient from mean water level to the epilitoral. The results seem to suggest that the factors affecting distribution are differences in 1. READ MORE
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5. Prospects for Bioenergy in Europe - Supply, Demand and Trade
Abstract : Renewable energy sources (RES), such as biomass, can be used to address two important issues in Europe: climate change and energy security. If biomass is produced sustainably and used efficiently, bioenergy contributes very little to CO2 emissions. READ MORE