Now showing items 11-20 of 32
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 ...
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 ...
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. 2 We developed a structural equation model based on data ...
Analyzing the proximity to cover in a landscape of fear: A new approach applied to fine-scale habitat use by rabbits facing feral cat predation on Kerguelen archipelago
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-03-07)
Although proximity to cover has been routinely considered as an explanatory variable in studies investigating prey behavioral adjustments to predation pressure, the way it shapes risk perception still remains equivocal. This paradox arises from both the ambivalent nature of cover as potentially both obstructive and protective, making its impact on risk perception complex and context-dependent, and ...
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)
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 ...
Transferability of biotic interactions: temporal consistency of arctic plant-rodent relationships is poor
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-09-17)
Variability in biotic interaction strength is an integral part of food web functioning. However, the consequences of the spatial and temporal variability of biotic interactions are poorly known, in particular for predicting species abundance and distribution. The amplitude of rodent population cycles (i.e., peak-phase abundances) has been hypothesized to be determined by vegetation properties ...
Stakeholder Perspectives on Triage in Wildlife Monitoring in a Rapidly Changing Arctic
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-11-15)
Monitoring activities provide a core contribution to wildlife conservation in the Arctic. Effective monitoring which allows changes in population status to be detected early provides opportunities to mitigate pressures driving declines. Monitoring triage involves decisions about how and where to prioritize activities in species and ecosystem based monitoring. In particular, monitoring triage examines ...
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 ...
Effects of changing permafrost and snow conditions on tundra wildlife: critical places and times
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-12-21)
The change of water phase around 0 °C has considerable impacts on wildlife ecology because liquid and solid water strongly differ in their insulating capability, mechanical resistance, and light reflectance. Freeze and melt events thus have strong ecological relevance, particularly in the Arctic where snow and ice are omnipresent and their conditions are changing due to climate warming. We first ...