Search for dissertations about: "niches"

Showing result 6 - 10 of 109 swedish dissertations containing the word niches.

  2. 6. Ecological and evolutionary assembly processes and metacommunity structure

    Author : Mikael Pontarp; Evolutionär ekologi; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Community; metacommunity; phylogenetic signal; ecology; evolution; assembly process; marine bacteria; habitat filtering; competition; mathematical modeling; simulation; eco-evolutionary;

    Abstract : This thesis aims to elucidate the link between abiotic and biotic effects and biogeographical contingencies, eco-evolutionary assembly processes, and community structure in a spatially explicit metacommunity framework. To this end, we used structure analysis of naturally sampled and experimentally manipulated marine bacterial communities and mathematical eco-evolutionary modeling and simulations of metacommunity assembly. READ MORE

  4. 7. Distribution and persistence of epiphyte metapopulations in dynamic landscapes

    Author : Victor Johansson; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES;

    Abstract : Habitat loss is a major cause of species extinction. Old trees have declined, and this continues because of poor management. Examples are development of secondary woodland in semi-open grasslands, and lack of natural tree regeneration. We therefore can expect that species associated with old tree are declining. READ MORE

  5. 8. Laminins in stemness and germ cell development in human

    Author : Magdalena Kurek; Karolinska Institutet; Karolinska Institutet; []
    Keywords : ;

    Abstract : Stem cell niches regulate the fine balance between self-renewal and differentiation of various stem cells. Although crucial hallmarks of stem cell niches, such as the mechanical signalling, neural inputs communicating distant cues, the proximity to blood vessels and the structural support by the surrounding basement membrane (BM), have been evaluated in different niches, little much attention has been directed to the specific composition of the BM. READ MORE

  6. 9. The dynamics of social movements : essays on competition and diffusion

    Author : Charlotta Stern; Peter Marsden; Stockholms universitet; []
    Keywords : SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; Sociology; sociologi;

    Abstract : In this thesis various aspects of social movement competition and diffusion is studied. The first part of the thesis focus on movement competition and especially on how competition relates to the ability of movements to attract members. READ MORE

  7. 10. Late Ordovician Faunal Distribution and Ecospace Partitioning in Marine Impact Craters : The Aftermath of the Lockne and Tvären Events

    Author : Åsa M Frisk; Lars Holmer; Jan Ove Ebbestad; Maurits Lindström; Alan Owen; Uppsala universitet; []
    Keywords : impact crater; Lockne; Tvären; ecospace; the Great Ordovician Biodiversification Event; NATURAL SCIENCES; NATURVETENSKAP;

    Abstract : In the Middle to Late Ordovician a boost of marine biodiversity occurred which is regarded as the most rapid diversity in Earth’s history, and termed the Great Ordovician Biodiversification Event. This time is also unique in that at least four marine meteorite craters with a good record of post-impact sediments are preserved in Baltoscandia. READ MORE