Søk
Viser treff 1-10 av 11
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, ...
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 ...
The importance of willow thickets for ptarmigan and hares in shrub tundra : the more the better?
(Journal article; Tidsskriftartikkel; Peer reviewed, 2012)
How spatial variation in areal extent and configuration of labile vegetation states affect the riparian bird community in Arctic Tundra
(Journal article; Tidsskriftartikkel; Peer reviewed, 2013)
The Arctic tundra is currently experiencing an unprecedented combination of climate change, change in grazing pressure by large herbivores and growing human activity. Thickets of tall shrubs represent a conspicuous vegetation state in northern and temperate ecosystems, where it serves important ecological functions, including habitat for wildlife. Thickets are however labile, as tall shrubs respond ...
Shedding new light on the diet of Norwegian lemmings: DNA metabarcoding of stomach content
(Journal article; Tidsskriftartikkel; Peer reviewed, 2013)
Lemmings are key herbivores in many arctic food webs, and their population dynamics have major impacts on the functioning of tundra systems. However, current knowledge of lemming diet is limited, hampering evaluation of lemming–vegetation interactions. This lack of knowledge is mainly due to methodological challenges, as previously used microhistological methods result in large proportions of poorly ...
Food web approach for managing Arctic wildlife populations in an era of rapid environmental change
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-05-28)
Scientists and wildlife managers implementing adaptive monitoring and management schemes, are tasked with providing predictions of population responses to harvest and environmental changes. Such predictions are useful not only to forecast direct effects of climate, productivity, land use, or habitat degradation, but also changes in the food web, such as expanding/increasing species that are predators, ...
Direct and indirect effects of environmental drivers on reindeer reproduction
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-05-27)
The impact of climate change on the dynamics of populations has been well documented and is widespread. However, weather variability influences populations both directly and indirectly, and is mediated by species interactions. This complexity may impede proper climate impact assessments. Hence, predicting the consequences of climate change may require including processes that occur both with time ...
Effect of scavenging on predation in a food web
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-04-26)
<ol>
<li>The fasting endurance hypothesis (FEH) predicts strong selection for large body size in mammals living in environments where food supply is interrupted over prolonged periods of time. The Arctic is a highly seasonal and food-restricted environment, but contrary to predictions from the FEH, empirical evidence shows that Arctic mammals are often smaller than their temperate conspecifics. ...
End-user involvement to improve predictions and management of populations with complex dynamics and multiple drivers
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-03-11)
Sustainable management of wildlife populations can be aided by building models
that both identify current drivers of natural dynamics and provide near-term predictions of
future states. We employed a Strategic Foresight Protocol (SFP) involving stakeholders to
decide the purpose and structure of a dynamic state-space model for the population dynamics
of the Willow Ptarmigan, a popular game species ...