Sökning: "Empetrum"

Visar resultat 1 - 5 av 6 avhandlingar innehållade ordet Empetrum.

1. 1. Future stratospheric ozone depletion will affect a subarctic dwarf shrub ecosystem

   Författare :Ulf Johanson; Biologiska institutionen; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Vaccinium; UVB; subarctic; shoot growth; ozone depletion; leaf thickness; irradiation system; heath ecosystem; Empetrum; dwarf shrubs; Calamagrostis; decomposition; Physiological biophysics; Växtfysiologi;

   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

3. 2. Temporal variation and phytotoxicity of Batatasin-III produced by Empetrum hermaphroditum

   Författare :Anna Wallstedt; Biologiska institutionen; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Palaeobotany; nitrogen uptake; photosynthesis; inhibition; temporal variation; chemical interference; boreal forest; Empetrum hermaphroditum; batatasin-III; phylogeny; palynology; Paleobotanik; fylogeni; palynologi; Biology; Biologi;

   Sammanfattning : In northern Sweden, the clonal dwarf shrub Empetrum hermaphroditum Hagerup exerts strong inhibitory effects on other plant species. These inhibitory effects may, at least in part, be attributed to the high production of the secondary metabolite, batatasin-III, which is released from leaves and transported to the soil by rain (throughfall) and snowmelt. LÄS MER

4. 3. Mountain vegetation in the Faroe Islands in a climate change perspective

   Författare :Anna Maria Fosaa; Biologiska institutionen; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; klimatologi; marklära; Växtekologi; Fysisk geografi; climatology; cartography; pedology; geomorphology; climate change.; Physical geography; Raunkiær´s life-forms; biodiversity; Vegetation zones; plant communities; Plant ecology; kartografi; geomorfologi;

   Sammanfattning : This thesis is a study of the mountain vegetation in the Faroe Islands based on five altitudinal transects sampled during the period 1999-2001. The vegetation was studied on the basis of plant communities, life-forms and biodiversity of vascular plant species and is discussed in a climate change perspective. LÄS MER

5. 4. Temporal and spatial variability of carbon cycling in a subarctic landscape

   Författare :Torbjörn Johansson; Institutionen för naturgeografi och ekosystemvetenskap; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Geologi; physical geography; Geology; Växtekologi; Plant ecology; Permafrost; Herbivory; Subarctic; Aerial photography; Vegetation change; Carbon balance; fysisk geografi;

   Sammanfattning : This thesis deals with the carbon balance in a subarctic landscape at different temporal and spatial scales. Its focus is mainly on the peatland and mountain birch forest (Betula pubescens ssp. czerepanovii) ecosystems within the Abisko area in northernmost Sweden. This is an area with a temperature close to the 0 OC mean annual isotherm. LÄS MER

7. 5. Event stratigraphy for the Last Glacial-Holocene transition in eastern middle Sweden

   Författare :Jonas Björck; Michael J.C Walker; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Last Glacial-Holocene transition; event stratigraphy; eastern middle Sweden; pollen; plant macrofossils; marine calcareous fossils; microtephra; radiocarbon dating; clay varve chronology; GRIP; ice-core chronology; calendar year chronology; Preboreal oscillation; Yoldia Sea; Baltic Ice Lake; Quaternary Geology; kvartärgeologi;

   Sammanfattning : This thesis outlines an event stratigraphy for the Last Glacial-Holocene transition in eastern middle Sweden. Events are short-lived occurrences that have left traces in the geological record and which, therefore, may be used for correlation and inter-regional comparisons. LÄS MER