Blar i NTNU Open på forfatter "Einum, Sigurd"
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No evidence for thermal transgenerational plasticity in metabolism when minimizing the potential for confounding effects
Kielland, Øystein Nordeide; Bech, Claus; Einum, Sigurd (Journal article; Peer reviewed, 2017)Environmental change may cause phenotypic changes that are inherited across generations through transgenerational plasticity (TGP). If TGP is adaptive, offspring fitness increases with an increasing match between parent ... -
Novel large-scale mapping highlights poor state of sea trout populations
Fiske, Peder; Forseth, Torbjørn; Thorstad, Eva Bonsak; Bakkestuen, Vegar; Einum, Sigurd; Falkegård, Morten; Garmo, Øyvind A.; Garseth, Åse Helen; Skoglund, Helge; Solberg, Monica Favnebøe; Utne, Kjell Rong; Vollset, Knut; Vøllestad, Leif Asbjørn; Wennevik, Vidar (Peer reviewed; Journal article, 2024)1. The state of sea trout in 1251 Norwegian watercourses was assessed based on a scoring system for human pressures, abundance data, and local knowledge. 2. Over 16,000 km of rivers and lakes were available to sea trout ... -
Offspring size effects vary over fine spatio-temporal scales in Atlantic salmon (Salmo salar)
Robertsen, Grethe; Skoglund, Helge; Einum, Sigurd (Journal article; Peer reviewed, 2013)Classic offspring-size theory predicts that a single level of investment per offspring maximizes parental reproductive success in a given environment. Yet, substantial variation in offspring size is often observed among ... -
The old and the large may suffer disproportionately during episodes of high temperature: evidence from a keystone zooplankton species
Burton, Tim; Einum, Sigurd (Peer reviewed; Journal article, 2020)Widespread declines in the body size of aquatic ectotherms have been attributed to the poorer ability of older, larger individuals to tolerate high temperature. Here, using the thermal death time curve framework, we ... -
On the use of the coefficient of variation to quantify and compare trait variation
Pelabon, Christophe; Hilde, Christoffer Høyvik; Einum, Sigurd; Gamelon, Marlène (Peer reviewed; Journal article, 2020)Meaningful comparison of variation in quantitative trait requires controlling for both the dimension of the varying entity and the dimension of the factor generating variation. Although the coefficient of variation (CV; ... -
Ontogenetic timing of density dependence: location-specific patterns reflect distribution of a limiting resource
Teichert, Maxim; Einum, Sigurd; Finstad, Anders Gravbrøt; Ugedal, Ola; Forseth, Torbjørn (Journal article; Peer reviewed, 2013)Theoretical considerations suggest that the relative abundance of age-specific limiting resources determines the ontogenetic timing of density dependence. Structural shelters may represent one such resource which can become ... -
Population dynamics and resting egg production in Daphnia: Interactive effects of mercury, population density and temperature
Issa, Semona; Simonsen, Ane; Jaspers, Veerle; Einum, Sigurd (Peer reviewed; Journal article, 2021)Toxicity studies on freshwater organisms are commonly conducted by quantifying effects on asexual (clonal) reproductive rates in Daphnia, whereas studies of effects on sexual reproductive rates remain relatively rare. ... -
Population regulation in the tadpole shrimp Lepidurus arcticus
Klausen, Torstein Rød (Master thesis, 2012)A metapopulation consists of several subpopulations that show limited degree of internal regulation, and are not viable alone in the long term. Instead, each subpopulation is sustained over time by migration and re-colonization ... -
Post-copulatory opportunities for sperm competition and cryptic female choice provide no offspring fitness benefits in externally fertilizing salmon
Lumley, Alyson J.; Diamond, Sian E.; Einum, Sigurd; Yeates, Sarah E.; Peruffo, Danielle; Emerson, Brent C.; Gage, Matthew J.G. (Journal article; Peer reviewed, 2016)There is increasing evidence that females can somehow improve their offspring fitness by mating with multiple males, but we understand little about the exact stage(s) at which such benefits are gained. Here, we measure ... -
Predation of Atlantic salmon across ontogenetic stages and impacts on populations
Falkegård, Morten; Lennox, Robert; Thorstad, Eva Bonsak; Einum, Sigurd; Fiske, Peder; Garmo, Øyvind Aaberg; Garseth, Åse Helen; Skoglund, Helge; Solberg, Monica Favnebøe; Utne, Kjell Rong; Vollset, Knut; Vøllestad, Leif Asbjørn; Wennevik, Vidar; Forseth, Torbjørn (Peer reviewed; Journal article, 2023)Managers and stakeholders increasingly ask whether predation is a driving force behind the poor status of many species, and whether predator control is likely to be a successful management action to intervene. We review ... -
Quantitative mismatch between empirical temperature-size rule slopes and predictions based on oxygen limitation
Einum, Sigurd; Bech, Claus; Kielland, Øystein Nordeide (Peer reviewed; Journal article, 2021)In ectotherms, adult body size commonly declines with increasing environmental temperature, a pattern known as the temperature-size rule. One influential hypothesis explaining this observation is that the challenge of ... -
Seasonal effects of hydropeaking on growth, energetics and movement of juvenile atlantic salmon (Salmo salar)
Puffer, Michael; Berg, Ole Kristian; Huusko, Ari; Vehanen, Teppo; Forseth, Torbjørn; Einum, Sigurd (Journal article; Peer reviewed, 2015)The performance and movements of juvenile Atlantic salmon Salmo salar exposed to variable water discharge (simulating hydropeaking) but with a stable water‐covered area were studied in six experimental stream channels, ... -
Size-dependent habitat use in juvenile Atlantic salmon (Salmo salar L.)
Hamnes, Frøydis Bolme (Master thesis, 2011). -
Snow Depth Alteration and Vegetation Cover Effects on Invertebrate Communities in Headwater Streams.
Aspaas, Aina Mærk (Master thesis, 2014)Climate change is expected to influence both snow cover and vegetation cover in the boreal zone. The length, duration and continuity of the snow cover during winter is expected to be altered, leading to increased occurrence ... -
Snow Depth and Vegetation Cover Effects on Ecological Functioning in Headwater Streams
Eikland, Knut Andreas (Master thesis, 2014)I studied the possible effects of reduced snow depth on ecological functioning including ecological processes like algal growth and the rates of grazing and decomposition in boreal headwater streams in the Dovre Mountains ... -
Sources of variation in metabolism of an aquatic ectotherm
Kielland, Øystein Nordeide (Doctoral theses at NTNU;2017:370, Doctoral thesis, 2017)Summary of thesis: An important aspect of ecology is being able to predict and explain how life can adapt to environmental changes. Paramount in making accurate predictions is the disentangling of trait variation, and ... -
Spatial variation in the relationship between performance and metabolic rate in wild juvenile Atlantic salmon
Robertsen, Grethe; Armstrong, JD; Nislow, KH; Herfindal, Ivar; Mckelvey, S; Einum, Sigurd (Journal article; Peer reviewed, 2014)Maintenance of metabolic rate (MR, the energy cost of self-maintenance) is linked to behavioural traits and fitness and varies substantially within populations. Despite having received much attention, the causes and ... -
Stochastic variation in gut bacterial community affects reproductive rates in the water flea Daphnia magna
Obrestad, Kathrine; Einum, Sigurd; Vadstein, Olav (Peer reviewed; Journal article, 2022)It is well-documented that perturbation of the gut bacterial community can influence the reproductive rates of the host. Less is known about how natural ecological processes can change the bacterial composition in the gut ... -
The effects of gut microbiota on fitness in Daphnia magna
Obrestad, Kathrine (Master thesis, 2020)Samlingen av mikrobielle samfunn i magetarmkanalen er formet av vertens genetikk, individer innen samme art og habitat, og miljøfaktorer. Endringer i sammensetningen til det mikrobielle samfunnet kan påvirke vertens fysiske ... -
Trait evolvability: effects of thermal plasticity and genetic correlations among traits
Fossen, Erlend Ignacio Fleck (Doctoral theses at NTNU;2018:377, Doctoral thesis, 2018)Summary of thesis: Trait evolvability: effects of thermal plasticity and genetic correlations among traits Climate change and increasing average temperatures are a big challenge for many populations of plants and ...