Sökning: "long-term geomorphology"

Visar resultat 1 - 5 av 11 avhandlingar innehållade orden long-term geomorphology.

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. Cenozoic landscape evolution in northern Sweden : Geomorphological interpretation within a GIS-framework

   Författare :Karin Ebert; Clas Hättestrand; Paul Bishop; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Long-term geomorphology; northern Sweden; base-level surface; inselbergs; digital elevation models; field observations; Physical geography; Naturgeografi; Physical Geography; naturgeografi;

   Sammanfattning : The large-scale bedrock landscape in northern Sweden has a complex evolution history of planation, uplift, transgression, burial, weathering, and erosion. The aim of this thesis is to examine the long-term development of the area. Terms for base-level surfaces in the area are defined. LÄS MER

5. 4. Dead-Ice Under Different Climate Conditions: Processes, Landforms, Sediments and Melt Rates in Iceland and Svalbard

   Författare :Anders Schomacker; Kvartärgeologi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; klimatologi; glacier; dead-ice; surge; ice-cored; Little Ice Age; fysisk geografi; Geologi; Geology; Svalbard; Iceland; Sedimentology; cartography; pedology; geomorphology; Sedimentologi; Physical geography; geomorfologi; marklära; kartografi; climatology;

   Sammanfattning : Modern dead-ice environments in the glacier forefields of Brúarjökull, Iceland and Holmströmbreen, Svalbard were investigated with focus on landform and sediment genesis, as well as quantification of melting. Field monitoring and studies of multi-temporal aerial photographs, satellite imagery, and Digital Elevation Models (DEMs) provided data for the melting quantification. LÄS MER

7. 5. Recent changes in land use and productivity in agro-pastoral Inner Mongolia, China

   Författare :Sara Brogaard; LUCSUS; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; geomorphology; Physical geography; China; Inner Mongolia; remote sensing; LUE model; primary production; GPP; yield variability; land degradation; farmers’ perception; productivity; Land use; pedology; cartography; climatology; Fysisk geografi; geomorfologi; marklära; kartografi; klimatologi;

   Sammanfattning : This study challenges the prevailing assumption that the expansion of cultivated land areas and increasing number of livestock in the agro-pastoral regions of northern China have aggravated the process of land degradation since the start of the rural reforms in 1978. Land-use and productivity trends in the Inner Mongolia Autonomous Region (IMAR), with special attention to the Keerqin steppe region, have been analysed. LÄS MER