Sökning: "umeå plant"

Visar resultat 21 - 25 av 143 avhandlingar innehållade orden umeå plant.

  1. 21. Plant-animal interactions and seed output of two insectpollinated herbs

    Författare :Anna R. Waites; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; plant reproduction; pollen limitation; pollinator behaviour; heterostyly; seed predation; Lythrum salicaria; Pedicularis palustris; stigma receptivity; self-pollen; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi;

    Sammanfattning : I combined comparative and experimental studies in the field and in the greenhouse to examine factors influencing reproductive success in two insect-pollinated herbs, the tristylous, selfincompatible perennial Lythrum salicaria and the self-compatible, biennial Pedicularis palustris. More specifically, I explored (i) the effects of plant population characteristics on the intensity and outcome of interactions with pollinators and seed predators, (ii) whether flower morphology affects duration of stigma receptivity, and (iii) whether damage-induced reduction in floral display reduces pollinator visitation and increases pollen limitation. LÄS MER

  3. 22. Ecosystem response to dam removal

    Författare :Anna G.C. Lejon; Christer Nilsson; Birgitta Malm Renöfält; Emily Stanley; Umeå universitet; []
    Nyckelord :dam removal; macroinvertebrates; plant species; plant succession; restoration; riparian zone; sediment deposition; species richness; Sweden; biology; biologi; ekologisk botanik; Ecological Botany; hydrologi; Hydrology;

    Sammanfattning : This thesis aims to improve our understanding of how riverine ecosystems respond to dam removal. Riverine and particularly riparian ecosystems are among the most variable and important features of all landscapes. LÄS MER

  4. 23. Systemic fungal diseases in natural plant populations

    Författare :Anders Wennström; Lars Ericson; Peter G. Ayres; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Systemic diseases; rust; smut; Puccinia minussensis; Lactuca sibirica; Puccinia pulsatillae; Pulsatilla pratensis; lateral growth; abiotic factors; disease transmission; Svampsjukdomar hos växter;

    Sammanfattning : The purpose of this thesis was to study interactions between systemic fungal diseases and perennial plants. Using the systemic rust Puccinia minussensis on the host plant Lactuca sibirica, and the rust Puccinia pulsatillae on the host plant Pulsatilla pratensis, this thesis focused on: (i) the effects of systemic diseases on their hosts (ii) host and pathogen responses to abiotic factors, (iii) the importance of life history strategies for understanding host-pathogen interactions, and (iv) the evolutionary consequences of living in close associations. LÄS MER

  5. 24. Population biology of the clonal plant Ranunculus lingua

    Författare :Mats E. Johansson; Christer Nilsson; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; clonal fragmentation; emergent macrophytes; fungal pathogens; hydrochoiy; invertebrate grazing; marginal population; Peronospora gigantea Prasocuris phellandrt regional abundance; rhizome production; size-number trade-off; vegetative reproduction; water-level fluctuation;

    Sammanfattning : The scope of this thesis was to identify, describe and quantify important life-history traits for the pseudoannual aquatic plant Ranunculus lingua in different ecological settings, by comparing populations from geographically marginal vs. central habitats. LÄS MER

  7. 25. Abiotic stress and plant-microbe interactions in Norway spruce

    Författare :Julia Christa Haas; Vaughan Hurry; Nathaniel Street; Torgny Näsholm; Jennifer Baltzer; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Norway spruce; boreal forest; cold; drought; bacteria; fungi; plant-microbe interactions; climate change;

    Sammanfattning : Norway spruce (Picea abies) is a dominant tree species in boreal forests with extensive ecological and economic value. Climate change is threatening these ecosystems, with rising temperatures impacting cold hardening and increasing drought stress in regions experiencing lower precipitation. LÄS MER