Blar i NTNU Open på forfatter "Grøtan, Vidar"
-
Interactions between demography and environmental effects are important determinants of population dynamics
Gamelon, Marlène; Grøtan, Vidar; Nilsson, Anna L. K.; Engen, Steinar; Hurrell, James W.; Jerstad, Kurt; Phillips, Adam S.; Røstad, Ole Wiggo; Slagsvold, Tore; Walseng, Bjørn; Stenseth, Nils Christian; Sæther, Bernt-Erik (Journal article; Peer reviewed, 2017)Climate change will affect the population dynamics of many species, yet the consequences for the long-term persistence of populations are poorly understood. A major reason for this is that density-dependent feedback effects ... -
Interactions between demography and environmental effects are important determinants of population dynamics
Gamelon, Marlène; Grøtan, Vidar; Nilsson, Anna; Engen, Steinar; Hurrell, James W.; Jerstad, Kurt; Phillips, Adam S.; Røstad, Ole Wiggo; Slagsvold, Tore; Walseng, Bjørn; Stenseth, Nils Christian; Sæther, Bernt-Erik (Journal article; Peer reviewed, 2017)Climate change will affect the population dynamics of many species, yet the consequences for the long-term persistence of populations are poorly understood. A major reason for this is that density-dependent feedback effects ... -
Life history traits and demography of a mountain bird under climatic variation
Eriksen, Lasse Frost (Doctoral theses at NTNU;2024:90, Doctoral thesis, 2024)Ongoing climate change can be expected to have major consequences for many species and ecosystems. Effects have been reported on reproduction, survival and movement ecology, with potential impacts for population dynamics ... -
The Moran effect revisited: spatial population synchrony under global warming
Hansen, Brage Bremset; Grøtan, Vidar; Herfindal, Ivar; Lee, Aline Magdalena (Peer reviewed; Journal article, 2020)The world is spatially autocorrelated. Both abiotic and biotic properties are more similar among neighboring than distant locations, and their temporal co-fluctuations also decrease with distance. P. A. P. Moran realized ... -
More frequent extreme climate events stabilize reindeer population dynamics
Hansen, Brage Bremset; Gamelon, Marlène; Albon, Steve D.; Lee, Aline Magdalena; Stien, Audun; Irvine, Robert Justin; Sæther, Bernt-Erik; Loe, Leif Egil; Ropstad, Erik; Veiberg, Vebjørn; Grøtan, Vidar (Journal article; Peer reviewed, 2019)Extreme climate events often cause population crashes but are difficult to account for in population-dynamic studies. Especially in long-lived animals, density dependence and demography may induce lagged impacts of ... -
No evidence of overall changes in spatial population synchrony across bird species in North America
Karlsen, Simen Christen (Master thesis, 2022)Populasjoner med sterkt korrelerte årlige fluktuasjoner i populasjonsstørrelse, har høy romlig populasjonssynkronitet. Dette øker ofte risikoen for utryddelse hos en art. Romlig autokorrelasjon i miljøstøy (eks. fluktuasjoner ... -
On the roles of density dependence and environmental fluctuations in driving ecoevolutionary dynamics of hole-nesting passerines
Vriend, Stefan J.G (Doctoral theses at NTNU;2022:125, Doctoral thesis, 2022)Ecology and evolution are intrinsically linked through an inevitable struggle for existence. This has been appreciated over very long timescales, such as the adaptation of organisms to the diverse environments across the ... -
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 ... -
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 patterns of plant growth in a warming high Arctic: insights from dendrochronology of Salix polaris
Sandal, Lisa (Master thesis, 2017)Climate change is most pronounced at high latitudes, where plant and animal populations are often strongly regulated by environmental drivers. Theory suggests that if these environmental drivers are synchronized over large ... -
Species data for understanding biodiversity dynamics: The what, where and when of species occurrence data collection
Petersen, Tanja Kofod; Speed, James David Mervyn; Grøtan, Vidar; Austrheim, Gunnar (Peer reviewed; Journal article, 2021)1. The availability and quantity of observational species occurrence records have greatly increased due to technological advancements and the rise of online portals, such as the Global Biodiversity Information Facility ... -
Stochastic rain events increase NDVI through moss water content: a High-Arctic field experiment
Valøen, Kristine (Master thesis, 2019)Målinger av ”Normalized Difference Vegetation Index” (NDVI) gjennom fjernmålinger blir brukt til å indikere produktiviteten til vegetasjonen i Høyarktis, og hvordan den påvirkes av klimaendringer. Tolkningen av observerte ... -
Temperature synchronizes temporal variation in laying dates across European hole-nesting passerines
Vriend, Stefan J.G.; Grøtan, Vidar; Gamelon, Marlène; Adriaensen, Frank; Ahola, Markus P.; Álvarez, Elena; Bailey, Liam D.; Barba, Emilio; Bouvier, Jean-Charles; Burgess, Malcolm D.; Bushuev, Andrey; Camacho, Carlos; Canal, David; Charmantier, Anne; Cole, Ella F.; Cusimano, Camillo; Doligez, Blandine F.; Drobniak, Szymon M.; Dubiec, Anna; Eens, Marcel; Eeva, Tapio; Erikstad, Kjell E.; Ferns, Peter N.; Goodenough, Anne E.; Hartley, Ian R.; Hinsley, Shelley A.; Ivankina, Elena; Juškaitis, Rimvydas; Kempenaers, Bart; Kerimov, Anvar B.; Kålås, John Atle; Lavigne, Claire; Leivits, Agu; Mainwaring, Mark C.; Martínez-Padilla, Jesús; Matthysen, Erik; van Oers, Kees; Orell, Markku; Pinxten, Rianne; Reiertsen, Tone Kristin; Rytkönen, Seppo; Senar, Juan Carlos; Sheldon, Ben C.; Sorace, Alberto; Török, János; Vatka, Emma; Visser, Marcel E.; Sæther, Bernt-Erik (Peer reviewed; Journal article, 2022)Identifying the environmental drivers of variation in fitness-related traits is a central objective in ecology and evolutionary biology. Temporal fluctuations of these environmental drivers are often synchronized at large ... -
Temporal and spatial variation in juvenile roe deer body mass
Lauvli, Elin Ovidia (Master thesis, 2020)Kroppsvekt tidlig i livet kan være en god indikator for hvor godt et individ vil gjøre det senere i livet. Det er derfor viktig å forstå de forskjellige mekanismene som påvirker kroppsvekt. Værforhold kan ha stor effekt ... -
The Role of the Arctic Fox in the Breeding Success of the Snow Bunting
Lenz, Kay Banu (Master thesis, 2022)The reproductive success of breeding birds can be determined by many different factors. One factor often associated with the failure of a brood is nest depredation. To avoid depredation, different bird species implement ... -
Understanding species interactions in the tropics: dynamics within and between trophic levels
Marjakangas, Emma-Liina (Doctoral theses at NTNU;2019:327, Doctoral thesis, 2019)Knowledge on how and why species interact with each other can provide invaluable insight into understanding the many-fold effects that the anthropogenic pressures have on biodiversity and ecosystem functioning. Multiple ... -
Urban aliens and threatened near-naturals: Land-cover affects the species richness of alien- and threatened species in an urban-rural setting
Petersen, Tanja Kofod; Speed, James David Mervyn; Grøtan, Vidar; Austrheim, Gunnar (Peer reviewed; Journal article, 2020)Urbanisation has strong effects on biodiversity patterns, but impacts vary among species groups and across spatial scales. From a local biodiversity management perspective, a more general understanding of species richness ... -
Urbanisation and land-cover change affect functional, but not compositional turnover of bird communities
Petersen, Tanja Kofod; Speed, James David Mervyn; Grøtan, Vidar; Frøyen, Yngve Karl; Austrheim, Gunnar (Peer reviewed; Journal article, 2023)Liver sinusoidal endothelial cells (LSECs) are fenestrated endothelial cells with a unique, high endocytic clearance capacity for blood-borne waste macromolecules and colloids. This LSEC scavenger function has been ...