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- Brunhoff, Cecilia, et al.
(författare)
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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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Ingår i: Journal of Biogeography. - : Wiley. - 1365-2699 .- 0305-0270. ; 33:12, s. 2136-2144
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Tidskriftsartikel (refereegranskat)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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| 2. |
- Henden, J-A, et al.
(författare)
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Phase-dependent effect of conservation efforts in cyclically fluctuating populations of Arctic fox (Vulpes lagopus).
- 2009
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Ingår i: Biological Conservation. - : Elsevier BV. - 0006-3207 .- 1873-2917. ; 142, s. 2586-2592
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Tidskriftsartikel (refereegranskat)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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