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Intrapopulation variability shaping isotope discrimination and turnover : experimental evidence in Arctic Foxes
(Journal article; Tidsskriftartikkel; Peer reviewed, 2011)
Tissue-specific stable isotope signatures can provide insights into the trophic ecology of consumers and their roles in food webs. Two parameters are central for making valid inferences based on stable isotopes, isotopic discrimination (difference in isotopic ratio between consumer and its diet) and turnover time (renewal process of molecules in a given tissue usually measured when half of the tissue ...
The importance of willow thickets for ptarmigan and hares in shrub tundra : the more the better?
(Journal article; Tidsskriftartikkel; Peer reviewed, 2012)
Interspecific and interploidal gene flow in Central European Arabidopsis (Brassicaceae)
(Journal article; Tidsskriftartikkel; Peer reviewed, 2011)
Effects of polyploidisation on gene flow between natural populations are little known. Central
European diploid and tetraploid populations of Arabidopsis arenosa and A. lyrata are here used to study interspecific and interploidal gene flow, using a combination of nuclear and plastid markers.
Ploidal levels were confirmed by flow cytometry. Network analyses clearly separated diploids according to ...
Toward understanding the effect of top predators on ecosystems
(Journal article; Tidsskriftartikkel, 2009)
To what extent top predators - carnivores at the top of food chains - drive or just respond to ecosystem dynamics is a central, but partially unresolved, question in ecology. In this report, we highlight how different research approaches employed in aquatic and terrestrial ecology may have a bearing on how the role of top predators in ecosystems is perceived.
Populasjonssykluser hos hare – drevet av rovdyr og spesielt gaupe
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-06-27)
Snøskohare – og gaupesyklusene i det boreale Nord-Amerika er et av de best kjente eksempler på populasjonssykluser. Sammenlignet med andre sykliske arter har denne syklusen en relativ konstant periode på 9–10 år. Haretettheten varierer typisk 20–30 ganger mellom topp- og bunnår. Mye økologisk forskning har ved hjelp av forskjellige metoder forsøkt å avdekke årsakene til snøskoharesyklusene, også med ...
Developing common protocols to measure tundra herbivory across spatial scales
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-03-12)
Understanding and predicting large-scale ecological responses to global environmental change requires comparative studies across geographic scales with coordinated efforts and standardized methodologies. We designed, applied, and assessed standardized protocols to measure tundra herbivory at three spatial scales: plot, site (habitat), and study area (landscape). The plot- and site-level protocols ...
Ancient origin and genetic segregation of canine circovirus infecting arctic foxes (Vulpes lagopus) in Svalbard and red foxes (Vulpes vulpes) in Northern Norway
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-08-12)
Canine circovirus (CanineCV) is a relatively new viral species, belonging to the family <i>Circoviridae</i>, whose pathogenic role is still uncertain. Since its first description in one domestic dog in 2011 from the USA, several reports have been documenting its distribution worldwide. Recently, CanineCV was also detected in wild animals such as wolves, foxes and badgers. In order to investigate the ...
Growth rings show limited evidence for ungulates’ potential to suppress shrubs across the Arctic
(Journal article; Tidsskriftartikkel; Peer reviewed, 2022-02-22)
Global warming has pronounced effects on tundra vegetation, and rising mean temperatures
increase plant growth potential across the Arctic biome. Herbivores may counteract the warming
impacts by reducing plant growth, but the strength of this effect may depend on prevailing regional
climatic conditions. To study how ungulates interact with temperature to influence growth of
tundra shrubs across ...
Sources of variation in small rodent trophic niche: New insights from DNA metabarcoding and stable isotope analysis
(Journal article; Tidsskriftartikkel; Peer reviewed, 2014-05-15)
Breeding den selection by Arctic foxes (Vulpes lagopus) in southern Yamal Peninsula, Russia
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-11-02)
Selecting the right location for a den during the breeding season is a type of habitat selection in the Arctic fox (Vulpes lagopus) that is likely to affect its reproductive success. A den’s suitability likely depends on its ability to provide shelter, as well as its proximity to prey resources. Depending on the different relative risks that Arctic foxes may face across their broad circumpolar range, ...