Sökning: "marginal populations"

Visar resultat 1 - 5 av 32 avhandlingar innehållade orden marginal populations.

  1. 1. Evolutionary ecology of arctic char (Salvelinus alpinus (L.)) : Intra- and interspecific interactions in circumpolar populations

    Författare :Johan Hammar; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Ecology; Arctic char; Salvelinus alpinus; biogeography; niche; life history; population ecology; intra- and interspecific interactions; cannibalism; competition; landlocked; marginal populations; species border; Ekologi; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi; Animal Ecology; zooekologi;

    Sammanfattning : This thesis examines a suite of ecological and genetic mechanisms influencing the fundamental and realized niche borders of European and North American populations of the Arctic char (Salvelinus alpinus (L.)) species complex in allopatry as well as in sympatry with brown trout (Salmo trutta) or brook trout (Salvelinus fontinalis). LÄS MER

  2. 2. Genetic structure and dispersal in plant populations

    Författare :Johan Fogelqvist; Martin Lascoux; Sophie Gerber; Beng-Olle Bengtsson; Uppsala universitet; []
    Nyckelord :population genetics; dispersal; structure; plant; gene flow;

    Sammanfattning : This thesis focuses on the spatial structure and methods to identify spatial structure in plants. Methods that investigate genetic structure can mainly be divided into equilibrium methods that reveal summed dispersal over many generations, and cluster methods, that reveal more recent dispersal events. LÄS MER

  3. 3. Population biology of the clonal plant Ranunculus lingua

    Författare :Mats E. Johansson; Christer Nilsson; Umeå universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; clonal fragmentation; emergent macrophytes; fungal pathogens; hydrochoiy; invertebrate grazing; marginal population; Peronospora gigantea Prasocuris phellandrt regional abundance; rhizome production; size-number trade-off; vegetative reproduction; water-level fluctuation;

    Sammanfattning : The scope of this thesis was to identify, describe and quantify important life-history traits for the pseudoannual aquatic plant Ranunculus lingua in different ecological settings, by comparing populations from geographically marginal vs. central habitats. LÄS MER

  4. 4. The spatial structure of genetic and morphometric variation in Corylus avellana (Betulaceae): pattern and scale

    Författare :Helena Persson; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; phytogeography; chemotaxonomy. Physiology of nonvascular plants; Systematisk botanik; taxonomi; morfologi; kemotaxonomi. Växters fysiologi inte kärlväxter .; taxonomy; morphology; Systematic botany; Öland; clonal structure; marginal and central populations; image analysis; aerial photographs; morphometric variation; allozymes; Corylus avellana; genetic variation;

    Sammanfattning : In the present thesis, I investigated the spatial structure of genetic and morphometric variation in the widespread wind-pollinated shrub Corylus avellana (L.) Betulaceae, hazel, and related the variation to geographic distribution and different spatial scales. LÄS MER

  5. 5. Periodontal health and disease in two adult populations in Sweden

    Författare :Åsa Wahlin; Malmö högskola; []
    Nyckelord :MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Parodontit; Livskavlitet;

    Sammanfattning : This thesis deals with epidemiological data regarding periodontaldisease from two different Swedish populations (Jönköping andSkåne).BackgroundThe studies focus on periodontal disease, a disease affecting a largepart of the adult population. LÄS MER