Sökning: "geographic distribution"

Visar resultat 1 - 5 av 114 avhandlingar innehållade orden geographic distribution.

  1. 1. Exploring Massive Volunteered Geographic Information for Geographic Knowledge Discovery

    Författare :Jia Tao; Jiang Bin; Harrie Lars; KTH; []
    Nyckelord :VGI; OSM; Geographic knowledge discovery; Zipf’s law; Urban sprawl;

    Sammanfattning : Conventionally geographic data produced and disseminated by the national mapping agencies are used for studying various urban issues. These data are not commonly available or accessible, but also are criticized for being expensive. However, this trend is changing along with the rise of Volunteered Geographic Information (VGI). LÄS MER

  3. 2. Geographic Distribution of Intra-specific Variation in Widespread Eurasian boreo-nemoral Woodland Herbs

    Författare :Torbjörn Tyler; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; kemotaxonomi. Växters fysiologi inte kärlväxter .; Plant genetics; Växtgenetik; morfologi; chemotaxonomy. Physiology of nonvascular plants; Systematisk botanik; taxonomi; phytogeography; morphology; taxonomy; historical biogeography; Systematic botany; allozymes; population differentiation; postglacial migration; genetic variation; geographic variation;

    Sammanfattning : Many woodland plant species have huge distribution areas covering large parts of the Eurasian continent including areas that were glaciated during the last glacial period. In the present thesis, the geographic distribution of variation within such species is investigated and discussed in relation to glacial survival and post-glacial migration, dispersal ability, breeding system and levels of gene-flow between populations and related species, and various methods to measure and analyse genetic variation. LÄS MER

  4. 3. The Principle of Scaling of Geographic Space and its Application in Urban Studies

    Författare :Xintao Liu; Bin Jiang; Yifang Ban; Meng Liqiu; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; geographic space; scaling; GIScience; VGI; OSM; heavy-tailed distribution; the head tail division rule; space syntax; nature street; urban sprawl; floating car data; hierarchical spatial structure;

    Sammanfattning : Geographic space is the large-scale and continuous space that encircles the earth and in which human activities occur. The study of geographic space has drawn attention in many different fields and has been applied in a variety of studies, including those on cognition, urban planning and navigation systems. LÄS MER

  5. 4. Morphometric differentiation in Papaver radicatum (Papaveraceae) : Geographic pattern and significance for refugial survival theory

    Författare :Eva Selin; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ecology; Capsule morphology; Geographic pattern; Leaf morphology; Morphometric variation; Papaver radicatum; Refugial survival; Seed shape; Ekologi; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi; ekologisk botanik; Ecological Botany;

    Sammanfattning : The morphometric pattern of variation among and within Scandinavian populations of the alpine species Papaver radicatum was studied. Results from analyses (including multivariate techniques) of capsule and leaf traits of wild-collected and cultivated plants as well as wild-collected seeds show correlated patterns of variation in capsule traits and partly corresponding patterns of variation between capsule and seed traits. LÄS MER

  7. 5. The plasticity and geography of host use and the diversification of butterflies

    Författare :Jessica Slove Davidson; Niklas Janz; Tommi Nyman; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Nymphalidae; host range; phylogeny; distribution; latitude; phylogeography; local specialisation; colonisation; host shift; polyphagy; speciation; diversification; zoologisk ekologi; Animal Ecology;

    Sammanfattning : Our world is changing rapidly and factors like urbanisation, changed agricultural practices and climate change are causing losses in butterfly diversity. It is therefore of importance to understand the source of their diversity. LÄS MER