Sökning: "boreal"

Visar resultat 16 - 20 av 370 avhandlingar innehållade ordet boreal.

1. 16. Hydrogeochemistry of Fe and Mn in small boreal catchments

   Författare :Louise Björkvald; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; hydrogeochemistry; Fe; Mn; boreal catchments; spring flood; Other earth sciences; Övrig geovetenskap;

   Sammanfattning : It is suggested that the overall understanding of the general hydrogeochemistry of a region is best understood from a landscape perspective. If so, this can provide useful information when planning monitoring programmes and influence of human activity. LÄS MER

3. 17. Colonization Patterns of Wood-inhabiting Fungi in Boreal Forest

   Författare :Jörgen Olsson; Lars Ericson; Jørund Rolstad; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Wood-inhabiting fungi; colonization; dispersal; restoration fire; saproxylic beetles; conservation; forest management; boreal forest; Terrestrial ecology; Terrestisk ekologi;

   Sammanfattning : Forest management practices have changed the over-all structure of the Fennoscandian forest landscape resulting in a lack of suitable substrates for many wood-inhabiting species. The objectives of this thesis was to describe the colonization patterns of wood-inhabiting fungi, including the potential role of beetles as dispersal vectors, on different types of dead wood substrate and assess the importance of active measures in the forest landscape in order to restore biodiversity i. LÄS MER

4. 18. Plants go with the flow : predicting spatial distribution of plant species in the boreal forest

   Författare :Ursula Zinko; Christer Nilsson; Håkan Rydin; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ecology; boreal forest; vascular plant; species richness; wetness index; soil pH; bryophyte; lichen; substrate; stand age; plot size; Ekologi; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi; ekologisk botanik; Ecological Botany;

   Sammanfattning : The main objectives of this thesis are to study if a topographic wetness index (TWI) could be used as a tool for predicting the spatial distribution of vascular plant species richness in the boreal forest as well as to study congruence in species richness between vascular plants, liverworts, mosses and lichens. A wetness index ln(a/tanβ) based on topography was used to assign a specific TWI-value to every 20 x 20m grid in two 25 km2 boreal forest landscapes (differing in average soil pH) in northern Sweden. LÄS MER

5. 19. The hidden life of plants : fine root dynamics in northern ecosystems

   Författare :Gesche Blume-Werry; Roland Jansson; Ann Milbau; Scott D. Wilson; Isla Myers-Smith; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Arctic; belowground; boreal; climate change; fine roots; heath; meadow; minirhizotron; permafrost; phenology; plant community; root biomass; root growth; root litter; root production; subarctic; tundra;

   Sammanfattning : Fine roots constitute a large part of the primary production in northern (arctic and boreal) ecosystems, and are key players in ecosystem fluxes of water, nutrients and carbon. Data on root dynamics are generally rare, especially so in northern ecosystems. LÄS MER

7. 20. The role of nutrients for stream ecosystem function in Arctic landscapes : drivers of productivity under environmental change

   Författare :Maria Myrstener; Ryan A. Sponseller; Reiner Giesler; Ann-Kristin Bergström; Tenna Riis; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Nutrients; Stream; Arctic; Boreal; Primary productivity; Algae; Biofilm; Nutrient limitation; Nitrogen; Phosphorus;

   Sammanfattning : Arctic and sub-Arctic freshwaters are currently experiencing substantial ecosystem changes due to the effects of global warming. Global warming effects on these freshwaters include increasing water temperatures, altered hydrological patterns, shifts in riparian vegetation and changes in the export of nutrients and carbon from soils. LÄS MER