English
norskBlar i forfatter "Hagen, Snorre"
Viser treff 1-10 av 10
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Genetic changes caused by restocking and hydroelectric dams in demographically bottlenecked brown trout in a transnational subarctic riverine system
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-04-29)Habitat discontinuity, anthropogenic disturbance, and overharvesting have led to population fragmentation and decline worldwide. Preservation of remaining natural genetic diversity is crucial to avoid continued genetic erosion. Brown trout (<i>Salmo trutta</i> L.) is an ideal model species for studying anthropogenic influences on genetic integrity, as it has experienced significant genetic alterations ... -
High resistance to climatic variability in a dominant tundra shrub species
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-06-05)Climate change is modifying temperature and precipitation regimes across all seasons in northern ecosystems. Summer temperatures are higher, growing seasons extend into spring and fall and snow cover conditions are more variable during winter. The resistance of dominant tundra species to these season-specific changes, with each season potentially having contrasting effects on their growth and survival, ... -
How rapidly do invasive birch forest geometrids recruit larval parasitoids? Insights from comparison with a sympatric native geometrid
(Journal article; Tidsskriftartikkel; Peer reviewed, 2013)Two related issues in studies of biological invasions are how quickly the enemy complexes of invasive species become as species-rich and efficient as those of native species and how important enemy release is for the establishment and spread of invaders. We addressed these issues for the geometrid moths Operophtera brumata and Agriopis aurantiaria, who invaded the coastal mountain birch forest ... -
Identification and Evaluation of 21 Novel Microsatellite Markers from the Autumnal Moth (Epirrita autumnata) (Lepidoptera: Geometridae)
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-09-17)The autumnal moth (Epirrita autumnata) is a cyclically outbreaking forest Lepidoptera with circumpolar distribution and substantial impact on Northern ecosystems. We have isolated 21 microsatellites from the species to facilitate population genetic studies of population cycles, outbreaks, and crashes. First, PCR primers and PCR conditions were developed to amplify 19 trinucleotide loci and two ... -
Loss of species and genetic diversity during colonization: Insights from acanthocephalan parasites in northern European seals
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-10-19)Studies on host–parasite systems that have experienced distributional shifts, range fragmentation, and population declines in the past can provide information regarding how parasite community richness and genetic diversity will change as a result of anthropogenic environmental changes in the future. Here, we studied how sequential postglacial colonization, shifts in habitat, and reduced host ... -
Niche construction mediates climate effects on recovery of tundra heathlands after extreme event
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-02-04)Climate change is expected to increase the frequency and intensity of extreme events in northern ecosystems. The outcome of these events across the landscape, might be mediated by species effects, such as niche construction, with likely consequences on vegetation resilience. To test this hypothesis, we simulated an extreme event by removing aboveground vegetation in tundra heathlands dominated by ... -
SARINOR WP 3 "SØK". (Norut rapport 11/2015)
(Research report; Forskningsrapport, 2015)Arbeidet analyserer tilgjengelig søk og redningskapasitet (SAR), med fokus på søk, med sikte på å avdekke forbedringspunkter. Arbeidet er begrenset til Norges ansvarsområde i henhold til Arktisk råds avtale om søk og redning i Arktis. Redningshelikopter på SAR beredskap består av 2 AS332L1 AWSAR på Svalbard, et Sea King på Banak og et i Bodø. I tillegg har Bristow et EC225 AWSAR helikopter i Hammerfest. ... -
Sea ice reduction drives genetic differentiation among Barents Sea polar bears
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-09-08)Loss of Arctic sea ice owing to climate change is predicted to reduce both genetic diversity and gene flow in ice-dependent species, with potentially negative consequences for their long-term viability. Here, we tested for the population-genetic impacts of reduced sea ice cover on the polar bear (<i>Ursus maritimus</i>) sampled across two decades (1995–2016) from the Svalbard Archipelago, Norway, ... -
Temporal analysis shows relaxed genetic erosion following improved stocking practices in a subarctic transnational brown trout population
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-08-30)Maintaining standing genetic variation is a challenge in human-dominated landscapes. We used genetic (i.e., 16 short tandem repeats) and morphological (i.e., length and weight) measurements of 593 contemporary and historical brown trout (Salmo trutta) samples to study fine-scale and short-term impacts of different management practices. These had changed from traditional breeding practices, using the ... -
Time to Rescue for Different Paths to Survival Following a Marine Incident
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-12-07)The time required for rescue is a critical factor for surviving a marine incident. The regulatory framework, International Maritime Organization (IMO) Polar Code, utilizes a risk-based approach. It states that the vessel operators are to define the time required for rescue but never less than 5 days. Based on experience from the classification society DNV GL, utilization of the minimum requirement ...
