Search for dissertations about: "transplant experiment"

Showing result 1 - 5 of 15 swedish dissertations containing the words transplant experiment.

  1. 1. Effects of climate change on boreal wetland and riparian vegetation

    Author : Lotta Ström; Roland Jansson; Christer Nilsson; Sarah Gergel; Umeå universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; biomass; flooding; hydrologic niche; invasibility; riparian zone; riparian plant species; river margin; climate scenario; seed sowing experiment; species composition; species richness; transplant experiment; Terrestrial ecology; Terrestrisk ekologi;

    Abstract : Models of climate change predict that temperature will increase during the 21th century and the largest warming will take place at high northern latitudes. In addition to warming, predictions for northern Europe include increased annual precipitation and a higher proportion of the precipitation during winter falling as rain instead of snow. READ MORE

  2. 2. Pollinator-mediated selection and the evolution of floral traits in orchids

    Author : Judith Trunschke; Jon Ågren; Nina Sletvold; Allan G. Ellis; Uppsala universitet; []
    Keywords : Among-population variation; Ecotype; Field experiment; Floral evolution; Germination; Local adaptation; Orchidaceae; Platanthera bifolia; Phenotypic selection; Pollination; Reciprocal transplant; Trait manipulation; Biology with specialization in Ecological Botany; Biologi med inriktning mot ekologisk botanik;

    Abstract : In this thesis, I combined manipulations of traits and pollination environment with analysis of phenotypic selection to examine causes of variation in strength and mode of selection on floral traits, and I conducted a reciprocal sowing experiment to test for local adaptation in germination success. I tested the following predictions (1) the opportunity for selection, and the strength of pollinator-mediated and net selection increase with increasing pollen limitation, (2) the effects of traits affecting pollinator attraction and traits affecting pollination efficiency are non-additive and this leads to pollinator-mediated correlational selection, (3) the effects of spur length on pollen removal, pollen receipt, and female fitness differ between populations with short-tongued and populations with long-tongued pollinators, and (4) local adaptation at the stage of germination contributes to the maintenance of ecotypes growing in grasslands and woodlands, respectively. READ MORE

  3. 3. Responses of boreal forest understory plant communities to climate and forestry

    Author : Ditte Marie Christiansen; Kristoffer Hylander; Johan Ehrlén; Signe Normand; Stockholms universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; boreal forests; bryophytes; climate; climate change; community temperature index; demography; forest management; microclimate; plants; species interactions; species distributions; time-lags; transplant experiment; understory communities; Ecology and Evolution; ekologi och evolution;

    Abstract : A warming climate is altering species distributions and community compositions. To understand and predict changes in species distributions to climate change, we often use species occurrences together with large-scale regional climate data. This can be problematic for several reasons. READ MORE

  4. 4. Survival of Cultured and Grafted Embryonic Dopaminergic Neurones - Effects of hypothermia and prevention of oxidative stress

    Author : Jenny Karlsson; Neurobiologi; []
    Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Neurology; 6-OHDA; lazaroid; PBN; brain; transplant; Parkinson s disease; dopamine; neuropsychology; neurophysiology; Neurologi; neuropsykologi; neurofysiologi;

    Abstract : Transplantation of embryonic dopaminergic neurones can ameliorate symptoms in Parkinson’s disease, but a major obstacle for clinical transplantations to overcome is the low survival (typically 5-10%) of implanted nigral neurones. If cell death in nigral grafts can be prevented, less embryonic tissue would be needed per transplantation session and hence more patients could receive intracerebral grafts as a therapy for Parkinson’s disease. READ MORE

  5. 5. Plant-Animal Interactions and Evolution of Floral Display and Flowering Phenology in Arabidopsis lyrata

    Author : Saskia Sandring; Jon Ågren; Johan Ehrlén; José Gómez; Uppsala universitet; []
    Keywords : Ecology; Arabidopsis lyrata; natural selection; floral display; phenology; flowering time; plant-animal interactions; pollination; herbivory; selection gradients; population differentiation; local adaptation; Ekologi;

    Abstract : In this thesis, I combined comparative and experimental approaches to examine selection on reproductive traits, and population differentiation in the insect-pollinated, outcrossing, perennial herb Arabidopsis lyrata. More specifically, I (1) determined whether selection on flowering phenology and floral display can be attributed to interactions with pollinators and herbivores, (2) examined whether population differentiation in flowering phenology and floral display is correlated with current selection on these traits, and (3) tested for local adaptation from contrasting environments in Europe. READ MORE