Sökning: "lotic"

Visar resultat 1 - 5 av 9 avhandlingar innehållade ordet lotic.

  1. 1. Salmonid behaviour under winter conditions

    Författare :Johan Watz; Larry Greenberg; Eva Bergman; John Piccolo; Richard Cunjak; Karlstads universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; climate change; drift; energy budget; foraging; grayling; ice cover; lotic; metabolic rate; predation; salmon; stream; stress; temperature; trout; Biology; Biologi;

    Sammanfattning : Winter conditions are believed to play an important role in the population dynamics of northern temperate stream fish, challenging the ability of fish to physiologically and behaviourally adapt. Climate change is predicted to increase both mean temperature and temperature fluctuations, especially during winter, leading to dynamic environmental conditions in terms of river ice production and flow. LÄS MER

  3. 2. 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 :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. 3. Winter behaviour of stream salmonids: effects of temperature, light, and ice cover

    Författare :Johan Watz; Larry Greenberg; Eva Bergman; John Piccolo; Svein Jakob Saltveit; Karlstads universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; stream salmonids; winter behaviour; efftect of temperatur; light; ice cover; environment; fish populations; Biology; Biologi;

    Sammanfattning : In boreal streams, stream salmonids typically face low water temperatures and variable ice conditions during winter, and thus stream salmonids are expected to use different behavioural strategies to cope with these environmental conditions. The studies presented in this thesis explore how temperature, light intensity, and surface ice affect salmonid behaviour, with focus on drift-feeding and ventilation rates. LÄS MER

  5. 4. Benthic diatoms in lakes : environmental drivers and ecological assessment

    Författare :Steffi Gottschalk; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : In order to protect or improve surface waters ecosystem response to pressures needs to be quantified. Diatoms are frequently used for assessing ecological status in streams and for reconstructing water quality of lakes. However, ecological status assessment of European lakes based on extant diatom assemblages is rare. LÄS MER

  7. 5. 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