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Climate Events Synchronize the Dynamics of a Resident Vertebrate Community in the High Arctic
(Peer reviewed; Research report; Forskningsrapport, 2013-01-18)
Recently accumulated evidence has documented a climate impact on the demography and dynamics of single species, yet the impact at the community level is poorly understood. Here, we show that in Svalbard in the high Arctic, extreme weather events synchronize population fluctuations across an entire community of resident vertebrate herbivores and cause lagged correlations with the secondary consumer, ...
Declining willow ptarmigan populations : the role of habitat structure and community dynamics
(Journal article; Tidsskriftartikkel; Peer reviewed, 2011)
The recent range contractions and population declines of many grouse species worldwide have been attributed to loss and fragmentation of their habitats, although the empirical evidence for the actual drivers is often weak. In case of the willow ptarmigan Lagopus lagopus in Fennoscandia, ungulate overbrowsing of willows has been hypothesized to exert such negative habitat-related impacts. Moreover, ...
Bird communities of the Arctic shrub tundra of Yamal: habitat specialists and generalists
(Journal article; Tidsskriftartikkel; Peer reviewed, 2012)
The ratio of habitat generalists to specialists in birds has been suggested as a good indicator of ecosystem changes due to e.g. climate change and other anthropogenic perturbations. Most studies focusing on this functional component of biodiversity originate, however, from temperate regions. The Eurasian Arctic tundra is currently experiencing an unprecedented combination of climate change, change ...
Assessing the causes of breeding failure among the rough-legged buzzard (Buteo lagopus) during the nestling period
(Journal article; Tidsskriftartikkel; Peer reviewed, 2012)
When food becomes scarce, the youngest nestlings in facultatively siblicidal raptor species typically die and such events are usually attributed to siblicide. Here we present results from an investigation in the Arctic tundra, in which rough-legged buzzard (Buteo lagopus) breeding success was monitored with regular visits to nests and time-lapse cameras that continuously recorded the activity of ...
Rapid, landscape scale responses in riparian tundra vegetation to exclusion of small and large mammalian herbivores
(Journal article; Tidsskriftartikkel; Peer reviewed, 2011)
Productive tundra plant communities composed of a variety of fast growing herbaceous and woody plants are likely to attract mammalian herbivores. Such vegetation is likely to respond to different-sized herbivores more rapidly than currently acknowledged from the tundra. Accentuated by currently changing populations of arctic mammals there is a need to understand impacts of different-sized herbivores ...
Population dynamics of tundra voles in relation to configuration of willow thickets in southern arctic tundra
(Journal article; Tidsskriftartikkel; Peer reviewed, 2011)
The areal extent and conWguration of thickets of
willow shrubs are currently changing in the Arctic both as an eVect of global warming and changed browsing pressure of reindeer. These changes have been predicted to impact the distribution and abundance of wildlife species relying on willow thickets as habitat. We assessed the relation between variables quantifying willow thicket configuration
and ...
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)
The ghost of development past : the impact of economic security policies on Saami pastoral ecosystems
(Journal article; Tidsskriftartikkel; Peer reviewed, 2011)
To ensure economic viability over time, any efforts to meet the Millennium Development
Goals need to reconcile conservation with development interventions. Particularly, in marginal and risk prone areas erosion of resilience could make production systems more susceptible to environmental risks that compromise the economic security. By longitudinal analyses of long-term data records we investigated
the ...
The Nature Index : a general framework for synthesizing knowledge on the State of Biodiversity
(Journal article; Tidsskriftartikkel; Peer reviewed, 2011)
The magnitude and urgency of the biodiversity crisis is widely recognized within scientific and political organizations. However, a lack of integrated measures for biodiversity has greatly constrained the national and international response to the biodiversity crisis. Thus, integrated biodiversity indexes will greatly facilitate information transfer from science toward other areas of human society. ...