Sökning: "overwintering"

Visar resultat 1 - 5 av 10 avhandlingar innehållade ordet overwintering.

1. 1. Lateral movements versus stationarity : adaptive alternatives in benthic invertebrates to the seasonal environment in a boreal river

   Författare :Tommy I. Olsson; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Benthic invertebrates; cold-hardiness; ice; migrations; overwintering; river; seasonal variations; spatial distribution; spring flood; water level;

   Sammanfattning : Benthic invertebrates inhabiting boreal rivers are exposed to very large seasonal variations in their physical environment. The extremes are in winter when the littoral area freezes solid and in spring when water flow increases rapidly. LÄS MER

3. 2. Thriving in extremes : Local adaptation of grasses (Poaceae) to geothermally heated soils on a subarctic island

   Författare :Jan-Niklas Nuppenau; Aelys M. Humphreys; Catarina Rydin; Johan Ehrlén; Alessandro Chiarucci; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; abiotic stress; Agrostis; cold; colonization history; common garden; extreme environments; Festuca; frost; ice encasement; Iceland; heat; overwintering; phenology; plastome; snown; thermal tolerance; Plant Systematics; växtsystematik;

   Sammanfattning : Temperature is one of the most decisive parameters when it comes to determining characteristics and distributions of life worldwide. For plants, as sessile organisms, it is particularly important to be able to deal with the temperatures they are exposed to at a given location. LÄS MER

4. 3. 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

5. 4. Ground beetle dynamics in intensively managed agricultural landscapes

   Författare :Erkki Palmu; Biologiska institutionen; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Carabidae; species richness; species diversity; functional traits; body size; emergence; dispersal; stable isotopes; deuterium; oxygen; crop diversification; landscape heterogeneity; agricultural management;

   Sammanfattning : In this thesis I have focused on studying dynamics of ground beetle assemblages in intensively managed agricultural landscapes. By definition, the land cover of these landscapes is dominated by annually tilled farmland, comprising a range of different crop types, in the context of the southern Swedish province of Scania mostly winter wheat, spring barley, winter rapeseed, and sugar beets. LÄS MER

7. 5. Empirical and theoretical studies of population trends and extinction risks

   Författare :Tobias Jeppsson; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : Empirical and theoretical approaches are needed to solve the current problem of increased extinction risk for many species. Thus, this thesis focuses on: (1) ways to estimate population trends for a large number of species, and (2) a predictive framework for identifying vulnerable populations from species traits or life history traits to allow for more proactive conservation actions. LÄS MER