Search for dissertations about: "ekologisk botanik"
Showing result 6 - 10 of 65 swedish dissertations containing the words ekologisk botanik.
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6. Wood-inhabiting fungi of alder forests in north-central Scandinavia : 1, Aphyllophorales (Basidiomycetes). Taxonomy, ecology and distribution
Abstract : Wood-inhabiting fungi were collected on different trees in 99 loca-' lities of alder woods, dominated by Alnus incana or occasionally A. glutinosa, in N-C Sweden and C Norway. Most of the localities are situated near the east coast of Sweden where the prevailing land elevation creates conditions suitable for colonization by alder. READ MORE
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7. The natural holocene vegetation development and the introduction of agriculture in northern Norrland, Sweden : studies of soil, peat and especially varved lake sediments
Abstract : The Holocene vegetation history of northern Norrland was studied by pollen analysis of sediement, peat and soil samples, with the aim to improve our knowledge about vegetation development in northern Norrland, and also about the history of man and the introduction of agriculture in the area. Earlier made pollen analyses from the four northernmost provinces were summarized and a series of new analyses from northern Norrland added. READ MORE
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8. Systemic fungal diseases in natural plant populations
Abstract : The purpose of this thesis was to study interactions between systemic fungal diseases and perennial plants. Using the systemic rust Puccinia minussensis on the host plant Lactuca sibirica, and the rust Puccinia pulsatillae on the host plant Pulsatilla pratensis, this thesis focused on: (i) the effects of systemic diseases on their hosts (ii) host and pathogen responses to abiotic factors, (iii) the importance of life history strategies for understanding host-pathogen interactions, and (iv) the evolutionary consequences of living in close associations. READ MORE
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9. Herbivory and plant community structure in a subarctic altitudinal gradient
Abstract : The object of this thesis was to study plant community structure, especially in relation to vertebrate herbivory, in an altitudinal gradient in the Fennoscandian mountain chain.A sowing experiment in a high alpine Ranunculus glacialis population showed that seeds germinated better in cleared microsites than under established individuals. READ MORE
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10. Life History and Tolerance and Resistance against Herbivores in Natural Populations of Arabidopsis thaliana
Abstract : 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. READ MORE