Avancerad sökning
Visar resultat 1 - 5 av 151 avhandlingar som matchar ovanstående sökkriterier.
1. Herbivores influence nutrient cycling and plant nutrient uptake : insights from tundra ecosystems
Sammanfattning : Reindeer appear to have strong positive effects on plant productivity and nutrient cycling in strongly nutrient-limited ecosystems. While the direct effects of grazing on vegetation composition have been intensively studied, much less is known about the indirect effect of grazing on plant-soil interactions. LÄS MER
2. Role of cadmium and ultraviolet-B radiation in plants, Influence on photosynthesis and element content in two species of Brassicaceae
Sammanfattning : Plants are exposed to many different stress factors during their lifetime, often more than one factor at a time, which highlights the importance of research regarding interaction among stress factors. Cadmium and ultraviolet-B radiation (UV-B, 280-315 nm) are two potential stress factors in the environment, which have gained increased interest due to atmospheric pollution. LÄS MER
3. Heavy metal contamination and toxicity : Studies of Macroalgae from the Tanzanian Coast
Sammanfattning : Concentrations of various metals are elevated above background levels in several intertidal areas along the Tanzanian coasts. However, there is little available information concerning the toxicity of these metals and how the uptake of these metals by bioindicators are influenced by external factors, such as heavy rains and increased coastal eutrophication, which tend to fluctuate. LÄS MER
4. 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
5. Haustoria regulation in the facultative parasitic plant Phtheirospermum japonicum
Sammanfattning : Parasitic plants are important agricultural pests that lead to considerable yield losses annually. Parasitic plants that completely rely on their hosts for their survival are known as obligatory parasites, whereas those independent of their hosts but parasitize under the right conditions are known as facultative parasitic plants. LÄS MER