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Visar resultat 11 - 15 av 40 avhandlingar som matchar ovanstående sökkriterier.
11. Linking plant population dynamics to the local environment and forest succession
Sammanfattning : Linking environmental variation to population dynamics is necessary to understand and predict how the environment influences species abundances and distributions. I used demographic, environmental and trait data of forest herbs to study effects of spatial variation in environmental factors on populations as well as environmental change in terms of effects of forest succession on field layer plants. LÄS MER
12. Life History and Tolerance and Resistance against Herbivores in Natural Populations of Arabidopsis thaliana
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
13. Molecular epidemiology of begomoviruses that infect vegetable crops in southwestern Cameroon
Sammanfattning : Begomoviruses are plant-infecting viruses, which are transmitted by the whitefly vector Bemisia tabaci. They have a genome of single-stranded DNA that consists of either a single (monopartite) or two components (bipartite) with a component size of approximately 2.8 kb. LÄS MER
14. What do snails do in ecosystems? it is a matter of traits
Sammanfattning : Current environmental changes demand the ability to predict possible consequences for ecosystems performing important functions regulating the Earth system, and providing essential services for human well-being. Indirect impacts can occur through changes in biotic communities. LÄS MER
15. Behavioural mechanisms behind aggregation in a tritrophic perspective
Sammanfattning : Gregarious organisms need to handle the trade-off between positive effects of group living and increasing food competition. The gregarious Phratora vulgatissima, a specialist leaf beetle on willow in Europe and Asia, frequently reaches outbreak densities in natural stands and short rotation coppices. LÄS MER