Search for dissertations about: "Ekologisk botanik"

Showing result 21 - 25 of 60 swedish dissertations containing the words Ekologisk botanik.

  1. 21. Plant Population Dynamics of Dodonaea angustifolia and Olea europaea ssp. cuspidata in Dry Afromontane Forests of Ethiopia

    University dissertation from Uppsala : Acta Universitatis Upsaliensis

    Author : Tesfaye Bekele; Uppsala universitet.; [2000]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Developmental biology; Demography; Dodonaea angustifolia; Elasticity; Establishment; Germination; Natural regeneration; Olea europaea ssp. cuspidata; Population structure; Recruitment; Seed bank; Survival; Utvecklingsbiologi; NATURAL SCIENCES Biology Organism biology Developmental biology; NATURVETENSKAP Biologi Organismbiologi Utvecklingsbiologi; Ecological Botany; Ekologisk botanik;

    Abstract : Human disturbance has led to excessive deforestation and to a very limited forest cover in the Afromontane zone of Ethiopia, which forms a large part of the country. Thus urgent conservation measures are required to ameliorate the situation. READ MORE

  2. 22. The ecological significance of cleistogamy

    University dissertation from Uppsala : Acta Universitatis Upsaliensis

    Author : Henrik Berg; Uppsala universitet.; [1998]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Ecology; bet-hedging; chasmogamous; enviromnental variation; fitness; outcrossing; progeny; selling; Ekologi; NATURAL SCIENCES Biology Terrestrial; freshwater and marine ecology; NATURVETENSKAP Biologi Terrestisk; limnisk och marin ekologi; ekologisk botanik; Ecological Botany;

    Abstract : Various aspects of cleistogamy, a reproductive system combining selfing in closed (cleistogamous) flowers and potential outcrossing in open (chasmogamous) flowers, were investigated in four perennial species. The main purpose was to shed some light on the adaptive value of having a dual reproductive strategy, and to test some hypotheses on the maintenance of xenogamy. READ MORE

  3. 23. Biodiversity in fragmented boreal forests assessing the past, the present and the future

    University dissertation from Uppsala : Acta Universitatis Upsaliensis

    Author : Håkan Berglund; Umeå universitet.; [2004]
    Keywords : 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; NATURAL SCIENCES Biology Terrestrial; freshwater and marine ecology; NATURVETENSKAP Biologi Terrestisk; limnisk och marin ekologi; ekologisk botanik; Ecological Botany;

    Abstract : 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. READ MORE

  4. 24. Macroalgae in the Baltic Sea responses to low salinity and nutrient enrichment in Ceramium and Fucus

    University dissertation from Umeå : Ekologi och geovetenskap

    Author : Lena Bergström; Umeå universitet.; [2005]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Ecology; adaptation; asexual reproduction; Baltic Sea; Gulf of Bothnia; salinity; macroalgae; nutrients; sexual reproduction; stress; Ekologi; NATURAL SCIENCES Biology Terrestrial; freshwater and marine ecology; NATURVETENSKAP Biologi Terrestisk; limnisk och marin ekologi; ekologisk botanik; Ecological Botany;

    Abstract : The brackish Baltic Sea is a marginal environment for both marine and freshwater species. The rate of ecological differentiation is presumably high due to strong selection pressure from a gradient of decreasing salinity that has been present in its current state for only about 3 000 years. READ MORE

  5. 25. Resource aquisition and allocation in lichens

    University dissertation from Umeå : Ekologi och geovetenskap

    Author : Lena Dahlman; Umeå universitet.; [2003]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Ecology; Amino acid; Arginine; carbohydrates; chlorophyll; ergosterol; microclimate; Lichen growth; nitrogen stress; photosynthesis; proteins; respiration; Symbiosis lichen ; nitrogene uptake; Ekologi; NATURAL SCIENCES Biology Terrestrial; freshwater and marine ecology; NATURVETENSKAP Biologi Terrestisk; limnisk och marin ekologi; ekologisk botanik; Ecological Botany;

    Abstract : 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. READ MORE