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Demersal fish assemblages in the boreo-Arctic shelf waters around Svalbard during the warm period 2007–2014
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-07-17)
The temporal and spatial resilience of abundance patterns of assemblages of organisms inhabiting transition zones between Arctic and boreal regions is an issue of concern in relation to climate change. The recognition that baseline information spanning such transition zones is required to facilitate future monitoring and assessments of temporal dynamics provided the motivation for the present study. ...
Long-term environmental monitoring for assessment of change: measurement inconsistencies over time and potential solutions
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-10-30)
The importance of long-term environmental monitoring and research for detecting and understanding changes in ecosystems and human impacts on natural systems is widely acknowledged. Over the last decades, a number of critical components for successful long-term monitoring have been identified. One basic component is quality assurance/quality control protocols to ensure consistency and comparability ...
Ungulate population monitoring in an open tundra landscape: distance sampling versus total counts
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-07-27)
Researchers and wildlife managers strive for low bias and high precision (i.e. high accuracy) when estimating animal population sizes. Distance sampling is currently one of the most widely used monitoring methods. However, it relies on strict sampling designs and modeling assumptions that can be difficult to meet in the field. Here, we use data from two sub-populations of non-migratory wild Svalbard ...
Circumpolar dynamics of a marine top-predator track ocean warming rates.
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-04-07)
Global warming is a nonlinear process, and temperature may increase in a stepwise manner. Periods of abrupt warming can trigger persistent changes in the state of ecosystems, also called regime shifts. The responses of organisms to abrupt warming and associated regime shifts can be unlike responses to periods of slow or moderate change. Understanding of nonlinearity in the biological responses to ...
Ecosystem drivers of an Arctic fox population at the western fringe of the Eurasian Arctic
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-08-16)
The distribution of traditional breeding dens on the Varanger Peninsula (70–71°N) in northernmost
Fennoscandia indicates that this area once harboured a large Arctic fox population.
Early 20th century naturalists regarded the coastal tundra of the Fennoscandian Low Arctic to
be a stronghold for the species. At the start of our research in 2004, however, the local Arctic
fox population was ...
Quantifying individual heterogeneity and its influence on life-history trajectories: different methods for different questions and contexts
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-09-25)
Heterogeneity among individuals influences the life‐history trajectories we observe at the population level because viability selection, selective immigration and emigration processes, and ontogeny change the proportion of individuals with specific trait values with increasing age. Here, we review the two main approaches that have been proposed to account for these processes in life‐history trajectories, ...
Gatekeepers to the effects of climate warming? Niche construction restricts plant community changes along a temperature gradient
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-06-20)
Organisms that modify the environment (niche constructors) are likely candidates to mediate the effects of climate warming. Here we assess tundra plant community changes
along a temperature gradient and how these are modified in the presence of the common
allelopathic dwarf shrub Empetrum nigrum and the large herbivore Rangifer tarandus.
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We developed a structural equation model based on data ...
Not only mosses: lemming winter diets as described by DNA metabarcoding
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-04-01)
The temporal dynamics of most tundra food webs are shaped by the cyclic population
dynamics of lemmings. While processes during winter may be behind the recent disruptions
of lemming cycles, lemming winter ecology is poorly known. We present here the first DNA metabarcoding data on the winter diet of Norwegian lemmings (Lemmus lemmus), based on feces collected after a winter of population ...