Search for dissertations about: "Disturbance gradient"

Showing result 1 - 5 of 20 swedish dissertations containing the words Disturbance gradient.

2. 1. Ecological and Evolutionary Consequences of Herbivory in the Perennial Herb Lythrum salicaria

   Author : Lina Lehndal; Jon Ågren; Peter Hambäck; Marc Johnson; Uppsala universitet; []
   Keywords : Disturbance gradient; Female reproductive success; Galerucella calmariensis; Galerucella pusilla; Herbivore removal; Latitudinal gradient; Local adaptation; Nanophyes marmoratus; Plant-herbivore interactions; Plant size; Resistance to herbivory; Tolerance to damage; Biology with specialization in Ecological Botany; Biologi med inriktning mot ekologisk botanik;

   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

4. 2. Numerical studies of transtion in wall-bounded flows

   Author : Ori Levin; Dan Henningson; Nikolaus Adams; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; boundary layer; suction; wall jet; streaks; waves; periodic disturbance; localized disturbance; turbulent spot; algebraic growth; exponential growth; stability; transition thresholds; transition prediction; PSE; DNS; Fluid mechanics; Strömningsmekanik;

   Abstract : Disturbances introduced in wall-bounded flows can grow and lead to transition from laminar to turbulent flow. In order to reduce losses or enhance mixing in energy systems, a fundamental understanding of the flow stability and transition mechanism is important. READ MORE

5. 3. Coral reefs in the Anthropocene : The effects of stress on coral metabolism and symbiont composition

   Author : Suzanne Faxneld; Michael Tedengren; Alina Szmant; Stockholms universitet; []
   Keywords : Corals; Disturbance; Galaxea fascicularis; ITS2; Metabolism; mtDNA; Pollution; Porites lutea; Symbiodinium; Temperature; Turbinaria mesenterina; Vietnam; Marine Ecotoxicology; marin ekotoxikologi;

   Abstract : Coral reefs constitute some of the most prolific and diverse ecosystems on our planet, but also among the most threatened. This thesis investigates the effects of environmental stressors on corals’ metabolism and symbiont diversity. READ MORE

6. 4. Modelling spatial and temporal species distribution in the Baltic Sea phytobenthic zone

   Author : Antonia Nyström Sandman; Hans Kautsky; Martin Isaeus; Georg Martin; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; species distribution modelling; niche; gradient; prediction; environmental factors; phytobenthos; scale; Marine ecology; Marin ekologi; Marine Ecology; marin ekologi;

   Abstract : Statistical modelling is often used to relate the presence or abundance of species to environmental predictors, thereby providing a basis for predictive mapping of species or biodiversity. The variables included must thus be relevant and reflect actual changes in the environment. READ MORE

7. 5. An experimental investigation of disturbance growth in boundary layer flows

   Author : Thomas Kurian; P. Henrik Alfredsson; Jens H. M. Fransson; Edward B. White; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Fluid mechanics; Strömningsmekanik; Other engineering mechanics; Övrig teknisk mekanik;

   Abstract : This thesis deals with the early stages of transition to turbulence in two different baseflows, namely the Falkner-Skan-Cooke boundary layer (FSC) and the asymptotic suction boundary layer (ASBL). Grid-generated turbulence is studied in order to characterise the isotropy levels, free-stream turbulence levels and characteristic length scales that will be present in the receptivity study. READ MORE