Sökning: "treeline"

Visar resultat 1 - 5 av 7 avhandlingar innehållade ordet treeline.

1. 1. Treeline dynamics in short and long term perspectives : observational and historical evidence from the southern Swedish Scandes

   Författare :Lisa Öberg; Bengt-Gunnar Jonsson; Leif Kullman; Ulf Segerström; Mittuniversitetet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Betula pubescens ssp. czerepanovii; Picea abies; Pinus sylvestris; climate change; monitoring; treeline advance; clones; megafossils; immigration; Holocene; cryptic refugia; Swedish Scandes; Terrestrial ecology; Terrestrisk ekologi;

   Sammanfattning : Against the background of past, recent and future climate change, the present thesis addresses elevational shifts of alpine treelines in the Swedish Scandes. By definition, treeline refers to the elevation (m a.s.l. LÄS MER

3. 2. Treeline dynamics in short and long term perspectives : observational and historical evidence from the southern Swedish Scandes

   Författare :Lisa Öberg; Bengt-Gunnar Jonsson; Leif Kullman; Aage Paus; Mittuniversitetet; []
   Nyckelord :Betula pubescens ssp. czerepanovii; Picea abies; Pinus sylvestris; Larix sibirica; climate; Betula pubescens ssp. czerepanovii; Picea abies; Pinus sylvestris; Larix sibirica;

   Sammanfattning : Treelines in high-mountain regions are constrained by heat deficiency, although the working mechanisms are still not entirely understood. Observational and paleoecological studies on treeline performance may contribute to increased understanding of the treeline phenomenon in general. LÄS MER

4. 3. On the role of terrestrial ecosystems in a changing Arctic

   Författare :Adrian Gustafson; BECC: Biodiversity and Ecosystem services in a Changing Climate; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Northern high latitudes; Arctic climate change; climate-vegetation feedbacks; shrubs; shrubification; treeline migration; LPJ-GUESS; RCA-GUESS; nitrogen; carbon; Northern high latitudes; Arctic climate change; climate-vegetation feedbacks; shrubs; shrubification; treeline migration; LPJ-GUESS; RCA-GUESS; Nitrogen; Carbon;

   Sammanfattning : The global temperature rise is proportional to the cumulative amount of CO2 emissions to the atmosphere. This observation is consistent between climate models and historical observations. LÄS MER

5. 4. Small-scale climate variability and its ecosystem impacts in the sub-Arctic

   Författare :Zhenlin Yang; Institutionen för naturgeografi och ekosystemvetenskap; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : Abstract in Undetermined To improve our knowledge of climate change and its impacts on ecosystem services, and to inform local people and governments that need assistance with the development of mitigation and adaptation strategies, climate impacts need to be understood urgently at the smaller scale. On one hand, the microclimate/topoclimate is known to be strongly decoupled from the general macroclimate of the freely circulating atmosphere and cannot reliably be inferred from climate station data or conventional climate models. LÄS MER

7. 5. Geophysical Applications of Vegetation Modeling

   Författare :Jed O Kaplan; Biologiska institutionen; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Environmental chemistry; Växtbiokemi; Plant biochemistry; CH4; CO2; stable isotopes; carbon cycle; wetland; ice core; methane; Holocene; mammoths; tundra; ice age; LGM; biogeography; biome; biogeochemistry; Vegetation model; Miljökemi; Physical geography; geomorphology; pedology; cartography; climatology; Fysisk geografi; geomorfologi; marklära; kartografi; klimatologi;

   Sammanfattning : This thesis describes the development and selected applications of a global vegetation model, BIOME4. The model is applied to problems in high-latitude vegetation distribution and climate, trace gas production, and isotope biogeochemistry. LÄS MER