Sökning: " lichens"

Visar resultat 6 - 10 av 63 avhandlingar innehållade ordet  lichens.

1. 6. Epiphytic lichen responses to nitrogen deposition

   Författare :Otilia Johansson; Kristin Palmqvist; Johan Olofsson; Annika Nordin; Lars E Ericson; Peter Crittenden; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Lichens; air pollution; nitrogen deposition; phosphorus; growth; chlorophyll a; boreal forest; field experiment; irrigation; carbon based secondary compounds; Lavar; luftföroreningar; alg; svamp; kväve; fosfor; skog; Terrestrial ecology; Terrestrisk ekologi; ekologisk botanik; Ecological Botany;

   Sammanfattning : Nitrogen (N) deposition has increased globally over the last 150 years and further increase is predicted for the future. Nitrogen is an important nutrient for lichens, involved in many processes in both photobiont and mycobiont.  However, N can be a stressor, causing many lichens and lichen communities to disappear with increased deposition. LÄS MER

3. 7. The Nostoc Symbiont of Lichens : Diversity, Specificity and Cellular Modifications

   Författare :Per Paulsrud; Jack Meeks; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Developmental biology; Utvecklingsbiologi; Developmental biology; Utvecklingsbiologi; fysiologisk botanik; Physiological Botany;

   Sammanfattning : Cyanobacteria belonging to the genus Nostoc have the capacity to form symbiotic associations with a wide range of organisms. Diversity, specificity and cellular modifications of the symbiosis between Nostoc and fungi in the formation of lichens were investigated in this thesis. LÄS MER

4. 8. From pattern to process : Studies on limestone grassland, with emphasis on the bryophyte-lichen layer and its effects on vascular plants

   Författare :Manuela Zamfir; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ecology; Alvar; Bryophytes; Carousel model; Community structure; Competition; Dynanmics; Interactions; Lichens; PASFRAN; pattern analysis; Sweden; Ekologi; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi; ekologisk botanik; Ecological Botany;

   Sammanfattning : Patterns in space and time at different scales in the bryophyte-lichen layer, aud multi-species spatial patterns of bryophytes, lichens and vascular plants were studied in Avenetum limestone grassland on the Great Alvar of the Baltic Island of Öland, south-eastem Sweden.Spatiotemporal patterns of bryophytes and Iichens in grazed and ungrazed alvar grassland demonstrated that dominant species forming large patches were relatively stable in time, whereas less frequent species forming small patches were more mobile. LÄS MER

5. 9. Natural products from Bolivian plants

   Författare :José Vila; Centrum för analys och syntes; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Organisk kemi; Organic chemistry; lichens; Secondary metabolites; Bolivian plants;

   Sammanfattning : Bolivia has the most varied ecology in South America - the Amazonas rainforests, the dry forests of the Chaco, the mist forests, the punas and high Andean vegetation. Some general studies have been carried out on useful plants; traditional medicine has been practiced in parts of region for thousands of years, recognized and accepted for treatment of various diseases. LÄS MER

7. 10. Microclimate at range margins : Consequences for boreal forest understory species

   Författare :Caroline Greiser; Kristoffer Hylander; Johan Ehrlén; Eric Meineri; Miska Luoto; Alistair Jump; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; microclimate; species distribution; range dynamics; boreal forest; canopy cover; topography; soil moisture; air humidity; bryophytes; lichens; vascular plants; biotic interactions; forest management; biodiversity conservation; ekologi och evolution; Ecology and Evolution;

   Sammanfattning : A warmer climate will shift species distributional range margins poleward, but near-ground microclimates may modify these shifts. Cold-adapted northern species at their rear edge may survive locally in microrefugia with a colder microclimate, and warm-adapted southern species at their leading edge may colonize stepping stone habitats with a warmer microclimate. LÄS MER