| 1. |
- Ehrich, Dorothee, et al.
(author)
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Documenting lemming population change in the Arctic : Can we detect trends?
- 2020
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In: Ambio. - : Springer Science and Business Media LLC. - 0044-7447 .- 1654-7209. ; 49:3, s. 786-800
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Journal article (peer-reviewed)abstract
- Lemmings are a key component of tundra food webs and changes in their dynamics can affect the whole ecosystem. We present a comprehensive overview of lemming monitoring and research activities, and assess recent trends in lemming abundance across the circumpolar Arctic. Since 2000, lemmings have been monitored at 49 sites of which 38 are still active. The sites were not evenly distributed with notably Russia and high Arctic Canada underrepresented. Abundance was monitored at all sites, but methods and levels of precision varied greatly. Other important attributes such as health, genetic diversity and potential drivers of population change, were often not monitored. There was no evidence that lemming populations were decreasing in general, although a negative trend was detected for low arctic populations sympatric with voles. To keep the pace of arctic change, we recommend maintaining long-term programmes while harmonizing methods, improving spatial coverage and integrating an ecosystem perspective.
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| 2. |
- Elmhagen, Bodil, et al.
(author)
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Homage to Hersteinsson and Macdonald : climate warming and resource subsidies cause red fox range expansion and Arctic fox decline
- 2017
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In: Polar Research. - : Norwegian Polar Institute. - 0800-0395 .- 1751-8369. ; 36:suppl. 1
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Research review (peer-reviewed)abstract
- Climate change can have a marked effect on the distribution and abundance of some species, as well as their interspecific interactions. In 1992, before ecological effects of anthropogenic climate change had developed into a topical research field, Hersteinsson and Macdonald published a seminal paper hypothesizing that the northern distribution limit of the red fox (Vulpes vulpes) is determined by food availability and ultimately climate, while the southern distribution limit of the Arctic fox (Vulpes lagopus) is determined by interspecific competition with the larger red fox. This hypothesis has inspired extensive research in several parts of the circumpolar distribution range of the Arctic fox. Over the past 25 years, it was shown that red foxes can exclude Arctic foxes from dens, space and food resources, and that red foxes kill and sometimes consume Arctic foxes. When the red fox increases to ecologically effective densities, it can cause Arctic fox decline, extirpation and range contraction, while conservation actions involving red fox culling can lead to Arctic fox recovery. Red fox advance in productive tundra, concurrent with Arctic fox retreat from this habitat, support the original hypothesis that climate warming will alter the geographical ranges of the species. However, recent studies show that anthropogenic subsidies also drive red fox advance, allowing red fox establishment north of its climate-imposed distribution limit. We conclude that synergies between anthropogenic subsidies and climate warming will speed up Arctic ecosystem change, allowing mobile species to establish and thrive in human-provided refugia, with potential spill-over effects in surrounding ecosystems.
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| 3. |
- Post, Eric, et al.
(author)
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Ecological Dynamics Across the Arctic Associated with Recent Climate Change
- 2009
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In: Science. - : American Association for the Advancement of Science (AAAS). - 1095-9203 .- 0036-8075. ; 325:5946, s. 1355-1358
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Research review (peer-reviewed)abstract
- At the close of the Fourth International Polar Year, we take stock of the ecological consequences of recent climate change in the Arctic, focusing on effects at population, community, and ecosystem scales. Despite the buffering effect of landscape heterogeneity, Arctic ecosystems and the trophic relationships that structure them have been severely perturbed. These rapid changes may be a bellwether of changes to come at lower latitudes and have the potential to affect ecosystem services related to natural resources, food production, climate regulation, and cultural integrity. We highlight areas of ecological research that deserve priority as the Arctic continues to warm.
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| 4. |
- Henden, J-A, et al.
(author)
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Phase-dependent effect of conservation efforts in cyclically fluctuating populations of Arctic fox (Vulpes lagopus).
- 2009
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In: Biological Conservation. - : Elsevier BV. - 0006-3207 .- 1873-2917. ; 142, s. 2586-2592
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Journal article (peer-reviewed)abstract
- Predator populations with demographic cycles driven by multi-annual cycles of their key prey resourcecan be expected to be ‘‘cyclic phase sensitive” to management actions. We explored this by means ofmodelling in the case of the highly endangered Fennoscandian arctic fox population which is driven by4-year population cycles in small rodent prey. By using a model in which the management actionimproved arctic fox vital rate through increased resource availability, we show that arctic fox populationgrowth was most improved when management action was applied in the increase and decrease phase ofthe cycle. Except in the low phase of the cycle, the growth rate was more affected when the managementaction worked through improved reproduction than improved survival. There was a synergistic effect tobe gained by performing management action during multiple phases during a demographic cycle. Thuswe recommend that arctic fox conservation programs ought to be continuous in time, but with the highestintensities of management action in the phases of the cycle in which the target population is mostprone to respond.
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| 5. |
- Jansson, Roland, et al.
(author)
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Future changes in the supply of goods and services from natural ecosystems : prospects for the European north
- 2015
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In: Ecology and Society. - : Resilience Alliance. - 1708-3087. ; 20:3
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Journal article (peer-reviewed)abstract
- Humans depend on services provided by ecosystems, and how services are affected by climate change is increasingly studied. Few studies, however, address changes likely to affect services from seminatural ecosystems. We analyzed ecosystem goods and services in natural and seminatural systems, specifically how they are expected to change as a result of projected climate change during the 21st century. We selected terrestrial and freshwater systems in northernmost Europe, where climate is anticipated to change more than the global average, and identified likely changes in ecosystem services and their societal consequences. We did this by assembling experts from ecology, social science, and cultural geography in workshops, and we also performed a literature review. Results show that most ecosystem services are affected by multiple factors, often acting in opposite directions. Out of 14 services considered, 8 are expected to increase or remain relatively unchanged in supply, and 6 are expected to decrease. Although we do not predict collapse or disappearance of any of the investigated services, the effects of climate change in conjunction with potential economical and societal changes may exceed the adaptive capacity of societies. This may result in societal reorganization and changes in ways that ecosystems are used. Significant uncertainties and knowledge gaps in the forecast make specific conclusions about societal responses to safeguard human well-being questionable. Adapting to changes in ecosystem services will therefore require consideration of uncertainties and complexities in both social and ecological responses. The scenarios presented here provide a framework for future studies exploring such issues.
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| 6. |
- Angerbjörn, Anders, et al.
(author)
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Carnivore conservation in practice : replicatedmanagement actions on a large spatial scale
- 2013
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In: Journal of Applied Ecology. - : Wiley. - 0021-8901 .- 1365-2664. ; 50:1, s. 59-67
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Journal article (peer-reviewed)abstract
- More than a quarter of the world’s carnivores are threatened, often due to multiple andcomplex causes. Considerable research efforts are devoted to resolving the mechanisms behindthese threats in order to provide a basis for relevant conservation actions. However, evenwhen the underlying mechanisms are known, specific actions aimed at direct support for carnivoresare difficult to implement and evaluate at efficient spatial and temporal scales.2. We report on a 30-year inventory of the critically endangered Fennoscandian arctic foxVulpes lagopus L., including yearly surveys of 600 fox dens covering 21 000 km2. These surveysshowed that the population was close to extinction in 2000, with 40–60 adult animalsleft. However, the population subsequently showed a fourfold increase in size.3. During this time period, conservation actions through supplementary feeding and predatorremoval were implemented in several regions across Scandinavia, encompassing 79% of thearea. To evaluate these actions, we examined the effect of supplemental winter feeding andred fox control applied at different intensities in 10 regions. A path analysis indicated that47% of the explained variation in population productivity could be attributed to lemmingabundance, whereas winter feeding had a 29% effect and red fox control a 20% effect.4. This confirms that arctic foxes are highly dependent on lemming population fluctuationsbut also shows that red foxes severely impact the viability of arctic foxes. This study also highlightsthe importance of implementing conservation actions on extensive spatial and temporalscales, with geographically dispersed actions to scientifically evaluate the effects. We note thatpopulation recovery was only seen in regions with a high intensity of management actions.5. Synthesis and applications. The present study demonstrates that carnivore populationdeclines may be reversed through extensive actions that target specific threats. Fennoscandianarctic fox is still endangered, due to low population connectivity and expected climate impactson the distribution and dynamics of lemmings and red foxes. Climate warming is expected tocontribute to both more irregular lemming dynamics and red fox appearance in tundra areas;however, the effects of climate change can be mitigated through intensive managementactions such as supplemental feeding and red fox control.
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| 7. |
- Berteaux, Dominique, et al.
(author)
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Arctic and red foxes
- 2011
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In: Arctic WOLVES. - Quebec City, Quebec, Canada : Centre d’études nordiques, Université Laval. ; , s. 76-87
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Book chapter (other academic/artistic)
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| 8. |
- Brunhoff, Cecilia, et al.
(author)
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Glacial survival or late glacial colonization? Phylogeography of the root vole (Microtus oeconomus) in north-west Norway
- 2006
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In: Journal of Biogeography. - : Wiley. - 1365-2699 .- 0305-0270. ; 33:12, s. 2136-2144
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Journal article (peer-reviewed)abstract
- Aim It has been proposed that the root vole subspecies, Microtus oeconomus finmarchicus, survived the last glacial period on islands on the north-west coast of Norway. The Norwegian island of Andoya may have constituted the only site with permanent ice-free conditions. Geological surveys and fossil finds from Andoya demonstrate that survival throughout the last glacial maximum was probably possible for some plants and animals. In this study we aim to infer the recent evolutionary history of Norwegian root vole populations and to evaluate the glacial survival hypothesis. Methods DNA sequence variation in the mitochondrial cytochrome b gene was studied in 46 root voles from 19 localities. Location Northern Fennoscandia and north-west Russia with a focus on islands on the north-west coast of Norway. Results The phylogeographical analyses revealed two North European phylogroups labelled 'Andoya' and 'Fennoscandia'. The Andoya phylogroup contained root voles from the Norwegian islands of Andoya, Ringvassoya and Reinoya and two localities in north-west Russia. The Fennoscandian phylogroup encompassed root voles from the three Norwegian islands of Kvaloya, Hakoya and Arnoya and the remaining specimens from Norway, northern Sweden and Finland. Nucleotide diversity within the Andoya and Fennoscandian phylogroups was similar, ranging from 0.5% to 0.7%. Main conclusions Both our genetic data and previously published morphological data are consistent with in situ glacial survival of root voles on Andoya during the last glacial maximum. However, the level of genetic diversity observed in the extant island populations, the past periods of severe climatic conditions on Andoya and the ecology of the root vole are somewhat difficult to reconcile with this model. A biogeographical scenario involving late glacial recolonization along the northern coasts of Russia and Norway therefore represents a viable alternative. Our results demonstrate that complex recolonization and extinction histories can generate intricate phylogeographical patterns and relatively high levels of genetic variation in northern populations.
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| 9. |
- Callaghan, Terry V., et al.
(author)
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Biodiversity, distributions and adaptations of arctic species in the context of environmental change
- 2004
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In: Ambio: a Journal of Human Environment. - : Royal Swedish Academy of Sciences. - 0044-7447. ; 33:7, s. 404-417
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Research review (peer-reviewed)abstract
- The individual of a species is the basic unit which responds to climate and UV-B changes, and it responds over a wide range of time scales. The diversity of animal, plant and microbial species appears to be low in the Arctic, and decreases from the boreal forests to the polar deserts of the extreme North but primitive species are particularly abundant. This latitudinal decline is associated with an increase in super-dominant species that occupy a wide range of habitats. Climate warming is expected to reduce the abundance and restrict the ranges of such species and to affect species at their northern range boundaries more than in the South: some Arctic animal and plant specialists could face extinction. Species most likely to expand into tundra are boreal species that currently exist as outlier populations in the Arctic. Many plant species have characteristics that allow them to survive short snow-free growing seasons, low solar angles, permafrost and low soil temperatures, low nutrient availability and physical disturbance. Many of these characteristics are likely to limit species responses to climate warming, but mainly because of poor competitive ability compared with potential immigrant species. Terrestrial Arctic animals possess many adaptations that enable them to persist under a wide range of temperatures in the Arctic. Many escape unfavorable weather and resource shortage by winter dormancy or by migration. The biotic environment of Arctic animal species is relatively simple with few enemies, competitors, diseases, parasites and available food resources. Terrestrial Arctic animals are likely to be most vulnerable to warmer and drier summers, climatic changes that interfere with migration routes and staging areas, altered snow conditions and freeze-thaw cycles in winter, climate-induced disruption of the seasonal timing of reproduction and development, and influx of new competitors, predators, parasites and diseases. Arctic microorganisms are also well adapted to the Arctics climate: some can metabolize at temperatures down to -39degreesC. Cyanobacteria and algae have a wide range of adaptive strategies that allow them to avoid, or at least minimize UV injury. Microorganisms can tolerate most environmental conditions and they have short generation times which can facilitate rapid adaptation to new environments. In contrast, Arctic plant and animal species are very likely to change their distributions rather than evolve significantly in response to warming.
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| 10. |
- Callaghan, Terry V., et al.
(author)
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Climate Change and UV-B Impacts on Arctic Tundra and Polar Desert Ecosystems: Key Findings and Extended Summaries
- 2004
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In: Ambio: a Journal of Human Environment. - 0044-7447. ; 33:7, s. 386-392
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Journal article (peer-reviewed)abstract
- The Arctic has become an important region in which to assess the impacts of current climate variability and amplification of projected global warming. This is because i) the Arctic has experienced considerable warming in recent decades (an average of about 3°C and between 4° and 5°C over much of the landmass); i) climate projections suggest a continuation of the warming trend with an increase in mean annual temperatures of 4–5°C by 2080; ii) recent warming is already impacting the environment and economy of the Arctic and these impacts are expected to increase and affect also life style, culture and ecosystems; and iv) changes occurring in the Arctic are likely to affect other regions of the Earth, for example changes in snow, vegetation and sea ice are likely to affect the energy balance and ocean circulation at regional and even global scales (Chapter 1 in ref. 1). Responding to the urgent need to understand and project impacts of changes in climate and UV-B radiation on many facets of the Arctic, the Arctic Climate Impact Assessment (ACIA) (1) undertook a four-year study. Part of this study (1–10) assessed the impacts of changes in climate and UV-B radiation on Arctic terrestrial ecosystems, both those changes already occurring and those likely to occur in the future. Here, we present the key findings of the assessment of climate change impacts on tundra and polar desert ecosystems, and xtended summaries of its components.
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