Search for dissertations about: "marginal populations"

Showing result 1 - 5 of 29 swedish dissertations containing the words marginal populations.

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

    University dissertation from Uppsala : Acta Universitatis Upsaliensis

    Author : Johan Hammar; Uppsala universitet.; [1998]
    Keywords : 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; NATURAL SCIENCES Biology Terrestrial; freshwater and marine ecology; NATURVETENSKAP Biologi Terrestisk; limnisk och marin ekologi; Animal Ecology; zooekologi;

    Abstract : 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). READ MORE

  2. 2. Genetic structure and dispersal in plant populations

    University dissertation from Uppsala : Acta Universitatis Upsaliensis

    Author : Johan Fogelqvist; Uppsala universitet.; [2008]
    Keywords : population genetics; dispersal; structure; plant; gene flow;

    Abstract : 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. READ MORE

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

    University dissertation from Umeå : Umeå universitet

    Author : Mats E. Johansson; Umeå universitet.; [1992]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; 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;

    Abstract : 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. READ MORE

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

    University dissertation from Helena Persson, Department of Ecology, Systematic Botany, Sölvegatan 37, SE-223 62 Lund, Sweden

    Author : Helena Persson; Lunds universitet.; Lund University.; [2002]
    Keywords : 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;

    Abstract : Popular Abstract in Swedish Spatiell struktur hos Corylus avellana (Betulaceae), hassel, med avseende på genetisk och morfometrisk variation Hassel, (Corylus avellana) är en vindpollinerad perenn buske som förekommer i mer eller mindre sammanhängande bestånd i stora delar av Europa. I denna avhandling har jag undersökt den genetiska och morfometriska variationen på olika hierarkiska nivåer hos hassel genom att använda förmodat neutrala karaktärer såsom allozymer och bladform. READ MORE

  5. 5. Species Delimitation and Phylogenetic Relationships. A study of Silene sections Atocion and Cryptoneurae

    University dissertation from Helena Persson, Department of Ecology, Systematic Botany, Sölvegatan 37, SE-223 62 Lund, Sweden

    Author : Zeynep Aydin; Göteborgs universitet.; Gothenburg University.; [2014]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Caryophyllaceae; Silene; Section Atocion; S. ertekinii; S. cryptoneura; S. aegyptiaca; SystematicsPhylogenetics; Species delimitation; Multispecies coalescent; Marginal likelihood; Species tree; DISSECT.;

    Abstract : Abstract The existence of conflicting genealogies of different genes through the evolution of species complicates the inference of phylogenetic relationships. The Multispecies Coalescent (MSC) model provides a theoretical background that account for the stochasticity in the genealogical process, thus providing systematists with a potentially objective way of testing alternative hypotheses of putative species. READ MORE