Sökning: "boreal region"

Visar resultat 1 - 5 av 49 avhandlingar innehållade orden boreal region.

1. 1. Boreal Forest Wildfire in a Changing Climate

   Författare :Johan Eckdahl; BECC: Biodiversity and Ecosystem services in a Changing Climate; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; boreal forest wildfire; carbon emissions; nutrient cycling; nitrogen; microbial community; plant community; climate chnge; secondary succession; Sweden; Fennoscandia; biodiversity; boreal skogsbrand; koldioxiduttsläpp; näringscykling; kväve; mirkobiellt samhälle; växtsamhälle; klimatförändring; sekundär succession; sverige; Fennoskandien; biologisk mångfald;

   Sammanfattning : The boreal region contains 40% of the earth’s carbon (C) that is stored in vegetation and soils with its forests accounting for almost 30% of the terrestrial C sink. Boreal forests are experiencing some of the most rapid rates of climatic warming and increases in fire activity, threatening to release large amounts of their dense C reserves to the atmosphere. LÄS MER

3. 2. Bacterial use of allochthonous organic carbon for respiration and growth in boreal freshwater systems

   Författare :Martin Berggren; Mats Jansson; Michael L. Pace; Umeå universitet; []
   Nyckelord :lakes; streams; boreal; bacterial respiration; bacterial production; bacterial growth efficiency; allochthonous organic carbon; low molecular weight compounds; naturgeografi; Physical Geography;

   Sammanfattning : Aquatic systems worldwide receive large amounts of organic carbon from terrestrial sources. This ‘allochthonous’ organic carbon (AlloOC) affects critical physical and chemical properties of freshwater ecosystems, with consequences for food web structures and exchange of greenhouse gases with the atmosphere. LÄS MER

4. 3. 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

5. 4. 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

7. 5. Modelling carbon uptake in Nordic forest landscapes using remote sensing

   Författare :Sofia Junttila; BECC: Biodiversity and Ecosystem services in a Changing Climate; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; forest; peatland; boreal region; remote sensing; carbon exchange; gross primary production; CO2; climate change; Sentinel-2;

   Sammanfattning : Boreal forests and peatlands store over 30% of the global terrestrial carbon in their vegetation and soil. but changing climate can compromise the current carbon stock. LÄS MER