Sökning: "dispersal"

Visar resultat 1 - 5 av 314 avhandlingar innehållade ordet dispersal.

  1. 1. Dispersal of bryophytes across landscapes

    Författare :Niklas Lönnell; Kristoffer Hylander; Bengt Gunnar Jonsson; Sebastian Sundberg; Johan Ehrlén; Risto Virtanen; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; anemochory; bryophytes; colonization; connectivity; diaspores; dispersal kernel; establishment; spore dispersal; long-distance dispersal; mechanistic model; mosses; realized dispersal; spore release; Lagrangian stochastic model; wind dispersal; Plant Ecology; växtekologi;

    Sammanfattning : Dispersal, especially long-distance dispersal, is an important component in many disciplines within biology. Many species are passively dispersed by wind, not least spore-dispersed organisms.In this thesis I investigated the dispersal capacity of bryophytes by studying the colonization patterns from local scales (100 m) to landscape scales (20 km). LÄS MER

  2. 2. Dispersal, inbreeding and fitness in natural populations

    Författare :Bengt Hansson; MEMEG; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; immigration; inbreeding; inbreeding depression; heterozygosity; microsatellite; great reed warbler; bird; Djurekologi; Animal ecology; philopatry; heritability; founder event; dispersal; bottleneck;

    Sammanfattning : To evaluate how inbreeding affects the viability of small populations, it is crucial to determine what constitutes a population (i.e., the number of breeders in local patches and the degree of dispersal), and also to estimate the reproductive consequences of philopatry and emigration. LÄS MER

  3. 3. 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

  4. 4. Distribution patterns of fleshy-fruited woody plants at local and regional scales

    Författare :Matilda Arnell; Ove Eriksson; Johan Ehrlén; Sara A.O. Cousins; Angela Moles; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Fleshy fruits; woody plants; dispersal; distribution patterns; range filling; dispersal limitation; historical land use; spatial associations; point-pattern analysis; recruitment; reproduction; pollination; fruit set; fruit-removal; Daphne mezereum; Plant Ecology; växtekologi;

    Sammanfattning : Fleshy-fruited woody plants share a long history with humans, providing us with food and wood material. Because of this relation, we have actively moved some of these plants across landscapes and continents. LÄS MER

  5. 5. Cooperative Breeding in the Southern Anteater-Chat : Sexual Disparity, Survival and Dispersal

    Författare :Jonathan Barnaby; Jan Ekman; Anssi Laurila; Rita Covas; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Southern anteater-chat; Myrmecocichla formicivora; cooperative breeding; social evolution; behavioural ecology; delayed dispersal; family living; Africa; Biologi med inriktning mot populationsbiologi; Biology with specialization in Population Biology;

    Sammanfattning : Group-living sets the scene for complex social behaviours such as cooperative breeding, and exploring the factors that shape group-living is crucial in understanding these behaviours. This thesis explores the ecology of a population of the facultative cooperative breeding southern anteater-chat (Myrmecocichla formicivora), a group-living bird species endemic to southern Africa. LÄS MER