Sökning: "Lichen"

Visar resultat 6 - 10 av 69 avhandlingar innehållade ordet Lichen.

  1. 6. Temperature effects on UV-B induced DNA damage and repair in plants and a lichen

    Författare :Markus Paulsson; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Tobacco Nicotiana tabacum ; Temperature; Subarctic; Plants; Photoreactivation; Photolyase; Lichen; DNA damage; Cyclobutane pyrimidine dimers CPD ; 6-4 Photoproducts; Cladonia arbuscula ssp. mitis; Ultraviolet radiation; UV-B; Vaccinium vitis-idaea; Plant genetics; Växtgenetik;

    Sammanfattning : All living organisms have DNA and since DNA is essential to life it must be repaired when damaged. UV radiation is one of the major DNA damaging agents, which photosynthetic organisms cannot avoid. LÄS MER

  3. 7. Resource aquisition and allocation in lichens

    Författare :Lena Dahlman; David Richardson; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ecology; Amino acid; Arginine; carbohydrates; chlorophyll; ergosterol; microclimate; Lichen growth; nitrogen stress; photosynthesis; proteins; respiration; Symbiosis lichen ; nitrogene uptake; Ekologi; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi; ekologisk botanik; Ecological Botany;

    Sammanfattning : Lichens are fascinating symbiotic systems, where a fungus and a unicellular alga, most often green (bipartite green algal lichens; 90% of all lichens), or a fi lamentous cyanobacterium (bipartite cyanobacterial lichens; 10% of all lichens) form a new entity (a thallus) appearing as a new and integrated organism: in about 500 lichens the fungus is associated with both a cyanobacterium and an alga (tripartite lichens). In the thallus, the lichen bionts function both as individual organisms, and as a symbiont partner. LÄS MER

  4. 8. Description of spatial and temporal distributions of epiphytic lichens

    Författare :Håkan Lättman; Per Milberg; Bengt Gunnar Jonsson; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; centroid; continuity; lichen; movement; range shift; direction; dispersal; ecological continuity; establishment; global change; global warming; habitat availability; håkan lättman; Biology; Biologi;

    Sammanfattning : Lichens are, in most cases, sensitive to anthropogenic factors such as air pollution, global warming, forestry and fragmentation. Two studies are included in this thesis. The first is an evaluation of the importance of old oak for the rare epiphytic lichen Cliostomum corrugatum (Ach.) Fr. LÄS MER

  5. 9. Phylogenetic and ecological studies in lichenology : including studies of both mycobiont and photobiont

    Författare :Åsa Dahlkild; Anders Tehler; Ingvar Kärnefelt; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Phylogeny; ecology; lichen; photobiont; mycobiont; Systematics and phylogenetics; Systematik och fylogeni;

    Sammanfattning : In this thesis different aspects in lichens are investigated, namely, the phylogeny of mycobiont and photobiont, and ecology in the form of species richness of certain habitats of the Uppland province, Sweden.Analyses of ITS sequences of the lichenized fungi genus Roccella (Roccellaceae) provide an intrageneric topology of the genus with emphasis on the European, Mediterranean and Macaronesian species. LÄS MER

  7. 10. Forest edges in boreal landscapes - factors affecting edge influence

    Författare :Ulrika Jansson; Per-Anders Esseen; Mats Nilsson; Timo Kuuluvainen; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; aerial photographs; edge contrast; edge density; edge length; fetch size; forest fragmentation; lichen growth; line intersect sampling; pendulous lichen; photo interpretation; skogskant; flygbild; kantlängd; lav; Terrestrial ecology; Terrestisk ekologi; ekologisk botanik; Ecological Botany;

    Sammanfattning : The boreal forest in Fennoscandia has been subjected to major loss and fragmentation of natural forests due to intensive forestry. This has resulted in that forest edges are now abundant and important landscape features. Edges have documented effects on the structure, function and biodiversity in forests. LÄS MER