Sökning: "dwarf shrubs"
Visar resultat 1 - 5 av 16 avhandlingar innehållade orden dwarf shrubs.
1. Future stratospheric ozone depletion will affect a subarctic dwarf shrub ecosystem
Sammanfattning : The stratospheric ozone depletion and the concomitant increase in ultraviolet-B (UV-B, 280-320 nm) radiation is of global concern due to the effects of UV-B on living organisms. To investigate the effects of increased levels of UV-B, a field irradiation system was established at a subarctic dwarf shrub heath in Northern Sweden (68 °N). LÄS MER
2. Effects of enhanced ultraviolet-B radiation on subarctic ecosystems
Sammanfattning : Biologically harmful ultraviolet-B radiation (UV-B, 280-320 nm) is increasing at the Earth´s surface owing to stratospheric ozone depletion. This is of global concern due to potential impacts of enhanced UV-B radiation on the biosphere. LÄS MER
3. Effects of herbivory on arctic and alpine vegetation
Sammanfattning : The distribution of plant species and functional traits in alpine and arctic environments are determined by abiotic conditions, but also by biotic interactions. In this thesis, I investigate interactions among plants and herbivory effects on plant community composition and plant functional traits in three different regions: Swedish Lapland, Beringia (USA/Russia) and Finnmark (Norway). LÄS MER
4. Late Weichselian and early Holocene changes of vegetation, climate and sea level on the Skagi peninsula, northern Iceland
Sammanfattning : Sediment sequences from five lakes on the Skagi peninsula, northern Iceland, were subjected to mineral magnetic analysis, carbon analysis, pollen analysis, plant macrofossil analysis, diatom analysis, radiocarbon dating and tephra analysis in order to make detailed reconstructions of vegetation, climate and sea level during the Late Weichselian and Early Holocene. The main purpose was to investigate if the dramatic deglacial climatic shifts recorded in proxy records from the North Atlantic region, such as ice cores, marine sediments and lake sediments, also are registered in Skagi lake sediments, which would be expected considering Iceland´s position in the middle of the North Atlantic Ocean, within the range of the Late Weichselian–Early Holocene migrations of the marine polar front. LÄS MER
5. Breaking the ice : effects of ice formation and winter floods on vegetation along streams
Sammanfattning : Streams in cold regions are characterized by unique hydrological processes that control flow regime and water levels. One of the most important processes is the formation, growth and melting of different types of ice in and around the stream channel during winter. LÄS MER
