Sökning: "Ecology"

Visar resultat 1 - 5 av 1358 avhandlingar innehållade ordet Ecology.

  1. 1. Stopover Ecology of Mallards Where, when and how to do what?

    Detta är en avhandling från Växjö : Linnaeus University Press

    Författare :Daniel Bengtsson; Linnéuniversitetet.; [2016]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Age characters; body condition; departure decision; effects of influenza A virus; habitat selection; mallard; movement; Ottenby Bird Observatory; stopover ecology; weather; wild birds; Ecology; Ekologi;

    Sammanfattning : The mallard (Anas platyrhynchos) is the most numerous and widespread duck in the northern hemisphere and a model species in ecology and harvest management. Migration is a crucial life stage for many birds and understanding the drivers of migration has important implications for conservation biology and assessment of animal population responses to global changes. LÄS MER

  2. 2. Evolutionary ecology of arctic char (Salvelinus alpinus (L.)) : Intra- and interspecific interactions in circumpolar populations

    Detta är en avhandling från Uppsala : Acta Universitatis Upsaliensis

    Författare :Johan Hammar; Uppsala universitet.; [1998]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ecology; Arctic char; Salvelinus alpinus; biogeography; niche; life history; population ecology; intra- and interspecific interactions; cannibalism; competition; landlocked; marginal populations; species border; Ekologi; NATURAL SCIENCES Biology Terrestrial; freshwater and marine ecology; NATURVETENSKAP Biologi Terrestisk; limnisk och marin ekologi; Animal Ecology; zooekologi;

    Sammanfattning : This thesis examines a suite of ecological and genetic mechanisms influencing the fundamental and realized niche borders of European and North American populations of the Arctic char (Salvelinus alpinus (L.)) species complex in allopatry as well as in sympatry with brown trout (Salmo trutta) or brook trout (Salvelinus fontinalis). LÄS MER

  3. 3. Predator-prey interactions in freshwater systems: The importance of chemical communication

    Detta är en avhandling från Kajsa Åbjörnsson, Limnology, Ecology Building, S-223 62 Lund, Sweden

    Författare :Kajsa Åbjörnsson; Lunds universitet.; Lund University.; [2002]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; aquatic ecology; marine biology; limnology; Marinbiologi; limnologi; akvatisk ekologi; Ecology; Ekologi; Hydrobiology; trophic cascades; non-lethal effects; benefits; costs; heredity; predator experience; alarmsubstances; dietary cues; amphibian larvae; invertebrates; visibility; fish; behaviour; Predator-prey; chemical cues;

    Sammanfattning : Predator released chemical cues provide a valuable source of information to prey organisms that can be used to alter their behaviour in order to reduce predation risk. In this thesis, I have examined under what circumstances chemical cues may be used by prey, and if prey discriminate between different cues. LÄS MER

  4. 4. Butterfly Diversity and Dispersal in Fragmented Grasslands

    Detta är en avhandling från Department of Ecology, Lund University

    Författare :Erik Öckinger; Lunds universitet.; Lund University.; [2006]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Djurekologi; Naturvetenskap; Animal ecology; Ekologi; Ecology; Lepidoptera; Landscape ecology; Insects; Species richness; Fragmentation; Mobility; Natural science; Source-sink dynamics; Metapopulations;

    Sammanfattning : During the last decades, the distribution and abundance of many European species of birds, plants and insects in agricultural landscapes have declined due to agricultural intensification. To be able to mitigate these declines, it is essential to know the relative importance on local and regional ecological processes on population persistence and patterns of species richness. LÄS MER

  5. 5. Methane dynamics in northern wetlands: Significance of vascular plants

    Detta är en avhandling från Department of Ecology, Lund University

    Författare :Anna Joabsson; Lunds universitet.; Lund University.; [2001]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; marine biology; aquatic ecology; Hydrobiology; Växtekologi; Plant ecology; climate change; arctic wetlands; northern wetlands; plant-microbe interactions; methane emission; vascular plants; limnology; Marinbiologi; limnologi; akvatisk ekologi; Ecology; Ekologi;

    Sammanfattning : The studies presented in Papers I to VI illustrate several different aspects of the impact of vascular plants on methane emissions from northern natural wetlands. The subject has been approached on different scales, ranging from the study of microbial substrates in the vicinity of a single plant root, to an attempt to extrapolate some of the results to the entire northern hemisphere north of 50°N. LÄS MER