Sökning: "Rare species"

Visar resultat 6 - 10 av 142 avhandlingar innehållade orden Rare species.

  1. 6. Microbially mediated formation of birnessite-type manganese oxides and subsequent incorporation of rare earth elements, Ytterby mine, Sweden

    Författare :Susanne Sjöberg; Christophe Dupraz; Rienk Smittenberg; Volker Brüchert; Helena Filipsson; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; microbial diversity; manganese oxides; birnessite; rare earth elements; subterranean; Ytterby mine; geokemi; Geochemistry;

    Sammanfattning : Microbes exert extensive control on redox element cycles. They participate directly orindirectly in the concentration and fractionation of elements by influencing the partitioningbetween soluble and insoluble species. LÄS MER

  2. 7. Biodiversity in fragmented boreal forests : assessing the past, the present and the future

    Författare :Håkan Berglund; Bengt Gunnar Jonsson; Jari Kouki; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ecology; bryophytes; CWD; edge effects; fragmentation; fungi; habitat destruction; historical records; indicator; lichens; regression; species-area relationship; value pyramids; woody debris; Ekologi; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi; ekologisk botanik; Ecological Botany;

    Sammanfattning : The aims of this thesis are to (1) analyze the predictability (indicators) of plant and fungal species diversity in old-growth forests, and (2) assess the history and biodiversity of woodland key habitats (WKHs) and their potential to maintain species diversity in fragmented boreal forest landscapes. Predictability was explored in Granlandet nature reserve, an unexploited landscape composed of discrete old-growth Picea forest patches of varying size isolated by wetland, reflecting conditions of insular biota at stochastic equilibrium. LÄS MER

  3. 8. The evolutionary ecology of niche separation : Studies on the sympatric butterflies Leptidea sinapis and Leptidea reali

    Författare :Magne Friberg; Wiklund Christer; John N. Thompson; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Lepidoptera; ecological character displacement; reproductive isolation; species discrimination; habitat; host plant; life history; sexual selection; female choice; Biology; Biologi; zoologisk ekologi; Animal Ecology;

    Sammanfattning : Studies of ecology and evolution have become largely integrated, and increasing attention is paid to the role of ecology for speciation and post speciation divergence. In this thesis I have applied an in-depth approach studying the ecology of a butterfly species pair; the morphologically virtually identical sister-species, the Wood white (Leptidea sinapis) and Reál’s wood white (Leptidea reali). LÄS MER

  4. 9. Plant Species Composition and Diversity in Cliff and Mountain Ecosystems

    Författare :Henrik Antonsson; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; cliff ecology; bryophytes; biodiversity; beta diversity; dispersal; facilitation; nurse plant; plant-plant interactions; Silene acaulis; stress;

    Sammanfattning : Ecosystems today are under increasing pressure from a rapidly changing climate, changes in land-use, habitat fragmentation and degradation and increasing anthropogenic disturbance. Studying drivers of biodiversity patterns is of increasing importance for understanding the dynamics of communities and their reactions and adaptation to changes in the future. LÄS MER

  5. 10. Structural and Functional Studies of Ribose-5-phosphate isomerase B

    Författare :Annette K. Roos; Sherry L. Mowbray; Torsten Unge; Constance Jeffery; Uppsala universitet; []
    Nyckelord :Molecular biology; Mycobacterium tuberculosis; reaction mechanism; cis-enediolate high energy intermediate; allose-6-phosphate isomerase; rare sugar; pentose phosphate pathway; Rv2465c; X-ray crystallography; Molekylärbiologi;

    Sammanfattning : Ribose 5-phosphate isomerase (Rpi) is one of the major enzymes of the pentose phosphate pathway, where it catalyses the inter-conversion of ribose 5-phosphate (R5P) and ribulose 5-phosphate. Two forms of this isomerase with no significant amino acid sequence similarity exist, RpiA and RpiB. LÄS MER