Sökning: "winter ecology"

Visar resultat 1 - 5 av 75 avhandlingar innehållade orden winter ecology.

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

    Författare :Johan Hammar; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; 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; Terrestrial; freshwater and marine ecology; 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

  2. 2. Sphagnum limits : Physiology, morphology and climate

    Författare :Charles Campbell; Håkan Rydin; Gustaf Granath; Sebastian Sundberg; Bengt-Gunnar Jonsson; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Sphagnum; ecology; bryophyte; winter; species distribution models; low temperature; plant structure; water economy; Biology with specialization in Ecological Botany; Biologi med inriktning mot ekologisk botanik;

    Sammanfattning : Sphagnum is the most important plant genus in terms of terrestrial carbon cycling. It and the habitats it creates store an equivalent of ~68% of the CO2 in the atmosphere. The genus has little dispersal limitation and the mire habitats are functionally similar at global scales. LÄS MER

  3. 3. Environmental-flow assessments for current and future run-off in a large river system regulated for hydropower production

    Författare :Åsa Widén; Roland Jansson; Birgitta Malm-Renöfält; Michael McClain; Umeå universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Environmental flows; eco-hydrology; hydropower; river ecosystem; environmental benefits; climate change; collaboration; resource management; Ekologisk reglering; vattenkraft; produktionsoptimering; hydrologi; hydraulik; akvatiskt ekosystem; miljönytta; klimatförändringar; samverkan; vattenresurs management;

    Sammanfattning : In 2019, Sweden implemented legislative changes to renegotiate hydropower permits to both consider environmental rehabilitation and to ensure national supply of hydropower. This means that efforts for environmental rehabilitation of the 2,000 hydropower plants in Sweden need to be considered. LÄS MER

  4. 4. Rarity in boreal stream: patterns, causes and consequences

    Författare :Per-Ola Hoffsten; Bo W. Svensson; Umeå universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Ecology; Central Sweden; site occupancy; dispersal limitation; natural disturbances; recolonization; flight-morphology; metapopulation; habitat stability; spring specialists; Crunoecia irrorata; niche limitation; Isogenus nubecula; nestedness; longitudinal distribution; Ekologi; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi; zooekologi; Animal Ecology;

    Sammanfattning : Patterns of site occupancy among boreal stream insects were studied in central Sweden with focus on sparsely distributed species and the role of dispersal and niche limitations.In the study of dispersal limitation, I found that effects of an extraordinarily harsh winter in small to medium-sized streams were strongest in sites located in small streams and far from lake outlets. LÄS MER

  5. 5. Ecology of red admiral migration

    Författare :Oskar Brattström; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Nymphalidae; Lepidoptera; migration patterns; migration; genetic structure; AFLP; lipid content; Inachis io; stable isotopes; orientation; navigation; weather; Animal ecology; red admiral; Vanessa atalanta; Djurekologi;

    Sammanfattning : The red admiral (Vanessa atalanta) is a migratory butterfly that can be found in North America, North Africa, Europe and some parts of Asia. In Europe the main part of the population spend winter in the Mediterranean region and the following spring leave this area to breed further to the north. LÄS MER