Blar i NTNU Open på forfatter "Sæther, Bernt-Erik"
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Population responses to harvesting in fluctuating environments
Lee, Aline Magdalena; jarillo, j; Peeters, Bart; Hansen, Brage Bremset; cao-garcia, francisco; Sæther, Bernt-Erik; Engen, Steinar (Peer reviewed; Journal article, 2021)Achieving sustainable harvesting of natural populations depends on our ability to predict population responses to the combined effects of harvesting and environmental fluctuations while accounting for other internal and ... -
Quantifying fixed individual heterogeneity in demographic parameters: Performance of correlated random effects for Bernoulli variables
Fay, Rémi; Authier, Matthieu; Hamel, Sandra; Jenouvrier, Stéphanie; van de Pol, Martijn; Cam, Emmanuelle; Gaillard, Jean-Michel; Yoccoz, Nigel G.; Acker, Paul; Allen, Andrew; Aubry, Lise M.; Bonenfant, Christophe; Caswell, Hal; Coste, Christophe; Larue, Benjamin; Le Coeur, Christie; Gamelon, Marlène; Macdonald, Kaitlin R.; Moiron, Maria; Nicol-Harper, Alex; Pelletier, Fanie; Rotella, Jay J.; Teplitsky, Celine; Touzot, Laura; Wells, Caitlin P.; Sæther, Bernt-Erik (Peer reviewed; Journal article, 2021)1. An increasing number of empirical studies aim to quantify individual variation in demographic parameters because these patterns are key for evolutionary and ecological processes. Advanced approaches to estimate individual ... -
Reversal of response to artificial selection on body size in a wild passerine bird
Kvalnes, Thomas; Ringsby, Thor Harald; Jensen, Henrik; Hagen, Ingerid Julie; Rønning, Bernt; Pärn, Henrik; Holand, Håkon; Engen, Steinar; Sæther, Bernt-Erik (Journal article, 2017)A general assumption in quantitative genetics is the existence of an intermediate phenotype with higher mean individual fitness in the average environment than more extreme phenotypes. Here we investigate the evolvability ... -
Seasonal and Diurnal Variation in Habitat Overlap of Roe Deer and Eurasian Lynx in a Human-Dominated Landscape
Utsi, Anne Isabelle (Master thesis, 2015)Predators affect prey directly (lethally), and indirectly (non-lethally), by altering their behaviour as they try to maximise habitat overlap with prey. Prey, on the other hand, are trying to minimise habitat overlap with ... -
Sensitivity Analysis of Effective Population Size to Demographic Parameters in House Sparrow Populations
Stubberud, Marlene Wæge (Master thesis, 2015)In population management, the effective population size, Ne, can be viewed in tandem with actual population size, N, as the main factors determining a population s long-term viability and sustainability. Ne is the number ... -
Sensitivity analysis of effective population size to demographic parameters in house sparrow populations
Stubberud, Marlene Wæge; Myhre, Ane Marlene; Holand, Håkon; Kvalnes, Thomas; Ringsby, Thor Harald; Sæther, Bernt-Erik; Jensen, Henrik (Journal article, 2017)The ratio between the effective and the census population size, (math formula), is an important measure of the long-term viability and sustainability of a population. Understanding which demographic processes that affect ... -
Sex-biased dispersal in water voles (Arvicola amphibius) in northern Norway
Stenersen, Trond Arne (Master thesis, 2017)Dispersal is key to the population dynamic in discrete habitats. There is variation in dispersal rate and range both between and within species, based on environmental variation and between both populations and individuals. ... -
Spatial covariation of competing species in a fluctuating environment
Lee, Aline Magdalena; Sæther, Bernt-Erik; Engen, Steinar (Journal article; Peer reviewed, 2020)Understanding how stochastic fluctuations in the environment influence population dynamics is crucial for sustainable management of biological diversity. However, because species do not live in isolation, this requires ... -
Spatial heterogeneity in climate change effects decouples the long‐term dynamics of wild reindeer populations in the high Arctic
Hansen, Brage Bremset; Pedersen, Åshild Ønvik; Peeters, Bart; Le Moullec, Mathilde; Albon, Steve D.; Herfindal, Ivar; Sæther, Bernt-Erik; Grøtan, Vidar; Aanes, Ronny (Journal article; Peer reviewed, 2019)The ‘Moran effect’ predicts that dynamics of populations of a species are synchronized over similar distances as their environmental drivers. Strong population synchrony reduces species viability, but spatial heterogeneity ... -
Spatial scales of population synchrony in predator-prey systems
Jarillo, Javier Diaz; Sæther, Bernt-Erik; Engen, Steinar; Cao-Garcia, Francisco (Peer reviewed; Journal article, 2020)Many species show synchronous fluctuations in population size over large geographical areas, which are likely to increase their regional extinction risk. Here we examine how the degree of spatial synchrony in population ... -
Spatial scaling of population synchrony in marine fish depends on their life history
Fredricson Marquez, Jonatan; Lee, Aline Magdalena; Aanes, Sondre; Engen, Steinar; Herfindal, Ivar; Salthaug, Are; Sæther, Bernt-Erik (Peer reviewed; Journal article, 2019)The synchrony of population dynamics in space has important implications for ecological processes, for example affecting the spread of diseases, spatial distributions and risk of extinction. Here, we studied the relationship ... -
Spatial structure and dispersal dynamics in a house sparrow metapopulation
Ranke, Peter Sjolte; Araya-Ajoy, Yimen; Ringsby, Thor Harald; Pärn, Henrik; Rønning, Bernt; Jensen, Henrik; Wright, Jonathan; Sæther, Bernt-Erik (Peer reviewed; Journal article, 2021)The effects of spatial structure on metapopulation dynamics depend upon the interaction between local population dynamics and dispersal, and how this relationship is affected by the geographical isolation and spatial ... -
Spatial variation in senescence rates in a bird metapopulation
Holand, Håkon; Kvalnes, Thomas; Gamelon, Marlène; Tufto, Jarle; Jensen, Henrik; Pärn, Henrik; Ringsby, Thor Harald; Sæther, Bernt-Erik (Journal article, 2016)Investigating factors which affect the decline in survival with age, i.e. actuarial senescence, is important in order to understand how demographic rates vary in wild populations. Although the evidence for the occurrence ... -
Spatial variation in the evolutionary potential and constraints of basal metabolic rate and body mass in a wild bird
Nafstad, Ådne Messel; Rønning, Bernt; Aase, Kenneth; Ringsby, Thor Harald; Hagen, Ingerid Julie; Ranke, Peter Sjolte; Kvalnes, Thomas; Stawski, Clare; Räsänen, Katja; Sæther, Bernt-Erik; Muff, Stefanie; Jensen, Henrik (Peer reviewed; Journal article, 2023)An organism's energy budget is strongly related to resource consumption, performance, and fitness. Hence, understanding the evolution of key energetic traits, such as basal metabolic rate (BMR), in natural populations is ... -
Spatiotemporal changes in vegetation following range expansion in Svalbard reindeer (Rangifer tarandus platyrhynchus)
Rønning, Marit Hegseth (Master thesis, 2014)Store planteetere som introduseres til nye områder er i stand til å modifisere abundansen og sammensetting av vegetasjonen, spesielt i områder uten predatorer. I dette studiet undersøkte jeg endringer i vegetasjonen i tre ... -
Spatiotemporal dynamics of avian communities
Sandal, Lisa (Doctoral thesis, 2023)Community ecology is the study of how different species interact with each other and their environment in a given habitat. In the face of rapid biodiversity loss, community ecology studies are more important than ever. ... -
Spatiotemporal variation in climatic conditions across ecosystems
Herfindal, Ivar; Aanes, Sondre; Benestad, Rasmus; Finstad, Anders Gravbrøt; Salthaug, Are; Stenseth, Nils Christian; Sæther, Bernt-Erik (Peer reviewed; Journal article, 2021)Environmental variation in time and space affects biological processes such as extinction risk and speed of adaptation to environmental change. The spatial structure of environmental variation may vary among ecosystems, ... -
Stabilizing selection and adaptive evolution in a combination of two traits in an arctic ungulate
Holand, Håkon; Kvalnes, Thomas; Røed, Knut; Holand, Øystein; Sæther, Bernt-Erik; Kumpula, Jukka (Journal article; Peer reviewed, 2020)Stabilizing selection is thought to be common in wild populations and act as one of the main evolutionary mechanisms, which constrain phenotypic variation. When multiple traits interact to create a combined phenotype, ... -
Structure of the G-matrix in relation to phenotypic contributions to fitness
Engen, Steinar; Sæther, Bernt-Erik (Peer reviewed; Journal article, 2021)Classical theory in population genetics includes derivation of the stationary distribution of allele frequencies under balance between selection, genetic drift, and mutation. Here we investigate the simplest generalization ... -
Sustainable management of populations impacted by harvesting and climate change
Stenseth, Nils Christian; Ims, Rolf Anker; Sæther, Bernt-Erik; Cadahia, Luis; Herfindal, Ivar; Lee, Aline Magdalena; Whittington, Jason D; Yoccoz, Nigel (Peer reviewed; Journal article, 2022)The sustainable use of natural resources is critical for addressing the global challenges of today. Strategies for sustainable harvesting need to consider not only harvested species, but also other non-harvested species ...