Search for dissertations about: "Seed predation"

Showing result 1 - 5 of 21 swedish dissertations containing the words Seed predation.

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

    University dissertation from Umeå : Ekologi, miljö och geovetenskap

    Author : Anna R. Waites; Umeå universitet.; [2005]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; plant reproduction; pollen limitation; pollinator behaviour; heterostyly; seed predation; Lythrum salicaria; Pedicularis palustris; stigma receptivity; self-pollen; NATURAL SCIENCES Biology Terrestrial; freshwater and marine ecology; NATURVETENSKAP Biologi Terrestisk; limnisk och marin ekologi;

    Abstract : 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. READ MORE

  2. 2. Effects of seed size and habitat on recruitment patterns in grassland and forest plants

    University dissertation from Stockholm : Department of Botany, Stockholm University

    Author : Karin Lönnberg; Stockholms universitet.; [2012]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Seed size; seedling establishment; seedling survival; recruitment; seed removal; co-existence; game-theory; Plant Ecology; växtekologi;

    Abstract : A trade-off between seed size and seed number is central in seed ecology, and has been suggested to be related to a trade-off between competition and colonization, as well as to a trade-off between stress tolerance and fecundity. Large seeds endure hazards during establishment, such as shading, drought, litter coverage and competition from other plants, better than do small seeds, due to a larger amount of stored resources in the seed. READ MORE

  3. 3. Plant-seed predator interactions – ecological and evolutionary aspects

    University dissertation from Stockholm : Botaniska institutionen

    Author : Hannah Östergård; Stockholms universitet.; [2008]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; apparent competition; community context; fruit abortion; defence; host range; monophagous; offence; oligophagous; plant-animal interactions; pre-dispersal seed predation; selection; spatio-temporal variation; NATURAL SCIENCES Biology; NATURVETENSKAP Biologi; Plant Ecology; växtekologi;

    Abstract : Plant-animal interactions are affected by both abundance and distribution of interacting species and the community context in which they occur. However, the relative importance of these factors is poorly known. READ MORE

  4. 4. The spatial and temporal dynamics of plant-animal interactions in the forest herb Actaea spicata

    University dissertation from Stockholm : Botaniska institutionen

    Author : Hugo von Zeipel; Stockholms universitet.; [2007]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Eupithecia immundata; parasitoid; rodent; seed predation; dispersal; recruitment; multitrophic; metapopulation; trophic cascades; community complexity; NATURAL SCIENCES Biology; NATURVETENSKAP Biologi; Plant Ecology; växtekologi;

    Abstract : Landscape effects on species performance currently receives much attention. Habitat loss and fragmentation are considered major threats to species diversity. Deciduous forests in southern Sweden are previous wooded pastures that have become species-rich communities appearing as islands in agricultural landscapes, varying in species composition. READ MORE

  5. 5. Pests and pest controlling organisms across tropical agroecological landscapes in relation to forest and tree-cover

    University dissertation from Stockholm : Department of Ecology, Environment and Plant Sciences, Stockholm University

    Author : Debissa Lemessa; Stockholms universitet.; [2014]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; activity abundance; crop raiding; exclosure experiment; homegarden; leaf damage; predation; spatial scales; structural complexity; Plant Ecology; växtekologi;

    Abstract : A major challenge in agroecosystems is how to manage the systems so that it reduces crop pests and enhances natural pest control. This thesis investigates patterns of crop pests and top-down effects of birds and arthropod predators in relation to land-use composition across spatial scales. READ MORE