Sökning: "treeline shifts"

Hittade 5 avhandlingar innehållade orden treeline shifts.

  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. 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

  7. 5. Impacts of Regional Climate Change on Swedish Forests: An Evaluation Using Process-based Regional Ecosystem Modelling Approach

    Författare :Deniz Koca; Institutionen för naturgeografi och ekosystemvetenskap; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; fysisk geografi; Geologi; Geology; physical geography; Sweden; forest management; diversity; carbon sequestration; net primary productivity; regional climate change; process-based regional ecosystem modelling;

    Sammanfattning : The overall aim of this thesis was to provide a representative estimate of the potential impacts of climate change and increased atmospheric CO2 concentrations on Swedish forest ecosystems and the key ecosystem services they provide. In order to achieve this task, fi rst LPJ-GUESS, a process-based regional ecosystem modelling framework, was applied to explore how possible shifts in climatic zones according to a range of regional climate scenarios may lead to changes in the tree species distribution and composition, net primary productivity (NPP) and carbon sequestration capacity of potential natural ecosystems on species level and at the regional scale. LÄS MER