| 1. |
- Bohdalkova, Leona, et al.
(författare)
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The response of a mid- and high latitude peat bog to predicted climate change : methane production in a 12-month peat incubation
- 2014
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Ingår i: Mitigation and Adaptation Strategies for Global Change. - : Springer. - 1381-2386 .- 1573-1596. ; 19:7, s. 997-1010
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Tidskriftsartikel (refereegranskat)abstract
- There are fears that global warming will lead to degradation of peatlands, higher emissions of greenhouse gases from peat, and accelerated warming. Anaerobic decomposition of organic soils produces methane (CH4), a potent greenhouse gas. Two peat bogs differing in mean annual temperature, Velke Darko (VD, Czech Republic, 7.2 A degrees C), and Stor myran (SA, Sweden, 4.0 A degrees C), were selected for a comparative study of how organic soils in different climatic zones will respond to warmer and drier conditions. Twenty peat cores from each bog were incubated in growth chambers. Under present-day summer conditions, VD produced 14 times more CH4 than SA. Two different warming scenarios were used. Peat-core replicates were kept at temperatures of 11 versus 16 A degrees C, and 11 versus 22 A degrees C. From 11 to 16 A degrees C, the CH4 production slightly decreased at SA, and slightly increased at VD. From 11 to 22 A degrees C, the CH4 production increased 9 times at SA, but slightly decreased at VD. After an 8-month incubation, peat cores under drying conditions (water table at -14 cm) were compared to samples with original water table (-2 cm). Drying conditions led to a steeper reduction in CH4 production at VD, compared to SA. The CH4 production decreased more than 100 times at VD. Then, the combined effect of simultaneous warming and drying at 11 and 22 A degrees C was studied. We did not find any significant effect of interactions between increasing temperature and decreasing water table level. Overall, the warmer site VD responded more strongly to the simulated climate change than the colder site SA.
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| 2. |
- Elmberg, Johan, et al.
(författare)
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Farmed European mallards are genetically different and cause introgression in the wild population following releases
- 2016
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Konferensbidrag (refereegranskat)abstract
- The practice of restocking already viable populations to increase harvest potential has since long been common in forestry, fisheries and wildlife management. The potential risks of restocking native species have long been overshadowed by the related issue of invasive alien species. However, during the last decade releases of native species with potentially non-native genome have received more attention. A suitable model to study genetic effects of large-scale releases of native species is the Mallard Anas platyrhynchos, being the most widespread duck in the world, largely migratory, and an important quarry species. More than 3 million unfledged hatchlings are released each year around Europe to increase local harvest. The aims of this study were to determine if wild and released farmed Mallards differ genetically, if there are signs of previous or ongoing introgression between wild and farmed birds, and if the genetic structure of the wild Mallard population has changed since large-scale releases started in Europe in the 1970s. Using 360 Single Nucleotide Polymorphisms (SNPs) we found that the genetic structure differed among historical wild, present-day wild, and farmed Mallards in Europe. We also found signs of introgression in the wild Mallard population, that is, individuals with a genetic background of farmed stock are part of the present free-living population. Although only a small proportion of the released Mallards appears to survive to merge with the free-living breeding population, their numbers are still so large that the genetic impact may have significance for the wild population in terms of individual survival and longterm fitness.
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| 3. |
- Elmberg, Johan, et al.
(författare)
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Farmed European mallards are genetically different and cause introgression in the wild population following releases
- 2016
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The practice of restocking already viable populations to increase harvest potential has since long been common in forestry, fisheries and wildlife management. The potential risks of restocking native species have long been overshadowed by the related issue of invasive alien species. However, during the last decade releases of native species with potentially non-native genome have received more attention. A suitable model to study genetic effects of large-scale releases of native species is the Mallard Anas platyrhynchos, being the most widespread duck in the world, largely migratory, and an important quarry species. More than 3 million unfledged hatchlings are released each year around Europe to increase local harvest. The aims of this study were to determine if wild and released farmed Mallards differ genetically, if there are signs of previous or ongoing introgression between wild and farmed birds, and if the genetic structure of the wild Mallard population has changed since large-scale releases started in Europe in the 1970s. Using 360 Single Nucleotide Polymorphisms (SNPs) we found that the genetic structure differed among historical wild, present-day wild, and farmed Mallards in Europe. We also found signs of introgression in the wild Mallard population, that is, individuals with a genetic background of farmed stock are part of the present free-living population. Although only a small proportion of the released Mallards appears to survive to merge with the free-living breeding population, their numbers are still so large that the genetic impact may have significance for the wild population in terms of individual survival and longterm fitness.
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| 4. |
- Kraus, R.H.S., et al.
(författare)
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Freigelassenes Federwild führt zu kontinent-weiter genetischer Introgression : die sich ändernde genetische Landschaft der Stockente Anas platyrhynchos in Europa
- 2015
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Konferensbidrag (refereegranskat)abstract
- Es ist eine seit langem übliche Praxis in Forstwirtschaft, Fischerei und allgemeinem Wildtiermanagement, Wildtierbestände gezielt aufzustocken. In den letzten ca. zehn Jahren haben aber solche Programme Aufmerksamkeit erregt, in denen lokale Bestände von Tierarten mit Individuen der gleichen Art, aber aus anderen Regionen und damit potentiell nicht-nativen Genomen aufgestockt wurden. Die Stockente Anas platyrhynchos ist ein geeignetes Modell um die genetischen Effekte solcher großskaligen Freisetzungen auf den einheimischen Genpool zu untersuchen, weil sie die am weitesten verbreitete und zahlreichste Entenart der Welt ist, über weite Strecken migrieren kann und gleichzeitig global das wichtigste Federwild darstellt. In vielen europäischen Ländern wird die Stockente seit etwa den frühen 1970er Jahren auch auf speziellen Farmen gezüchtet und zu Jagdzwecken ausgesetzt. So gehen aktuelle Schätzungen davon aus, dass jährlich etwa drei Millionen junge Enten nur zum Zweck der Aufstockung zur Jagd an europäischen Gewässern ausgesetzt werden. Die Ziele unserer Studie waren herauszufinden, ob sich Enten von Farmpopulationen genetisch von wilden Enten unterscheiden lassen, ob es Anzeichen früherer oder anhaltender genetischer Introgression zwischen diesen beiden Gruppen gibt und ob sich die genetische Struktur der wilden Entenpopulationen seit der großskaligen Entenaufstockung verändert hat. Dazu verwendeten wir 360 SNP Marker (Single Nucleotide Polymorhpism) um die genetische Struktur von historischen wilden Stockenten (Museumsproben), zeitgenössischen wilden Stockenten und Farm-Enten zu vergleichen (N = 591). Wir fanden klare genetische Unterschiede zwischen wilden Stockenten und Farm-Enten in mehreren Ländern Europas. Ebenfalls konnten wir genetische Introgression von Genen der Farm-Enten in die wilde Stockentenpopulation zeigen. Die Vermischung scheint bisher zwar messbar aber noch gering zu sein, da auf Farmen gezüchtete Stockenten in der Wildnis geringe Überlebensraten aufweisen. Dennoch sollte die weitere Einkreuzung von Farm-Enten in die wilden Stockentenpopulationen so gering wie möglich gehalten werden, da durch anhaltende genetische Introgression möglicherweise in Zukunft lokale Anpassungen der wilden Stockenten geschwächt werden, was eine Bedrohung dieser Bestände darstellen könnte.
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| 6. |
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| 7. |
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| 8. |
- Söderquist, Pär, et al.
(författare)
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Released game birds cause introgression in European mallard
- 2015
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Konferensbidrag (refereegranskat)abstract
- The practice of restocking already viable populations to improve harvest has since long been common in forestry, fisheries and wildlife management. The potential risks with restocking of native species has for a long time been overshadowed by the related issue of invasive species. However, during the last decade releases of native species with a potential non-native genome have attained more attention. A suitable model species for studying genetic effects of large-scale releases of a native species is the Mallard, Anas platyrhynchos; it is the most widespread duck in the world, it is a migrating species, and an important game bird. In several European countries it is also farmed and released to increase the harvestable population, and more than 3 million unfledged hatchlings are released each year around Europe. The aims of this study were to determine if wild and released farmed Mallards differed genetically among subpopulations in Europe, if there are signs of previous or ongoing introgression between wild and farmed Mallards, and if the genetic structure of the wild Mallard population has changed since large-scale releases started in the 1970s. We used 360 Single Nucleotide Polymorphisms (SNPs) to analyze the genetic structure of historical wild, present-day wild, and farmed Mallards. We found a clear genetic difference between wild and farmed Mallards in Europe. We also found signs of introgression of farmed genes in the wild Mallard population, however, the rate of hybridization is probably minor due to low survival of released farmed Mallards and a change of the wild population since the start of large-scale releases is therefore limited. A low level of hybridization between farmed and wild Mallard is desired as introgressed genes may be detrimental for wild Mallards, and efforts to increase survival of farmed Mallards should therefore not be encouraged.
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| 9. |
- Söderquist, Pär, et al.
(författare)
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Released game birds cause introgression in European mallard
- 2015
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The practice of restocking already viable populations to improve harvest has since long been common in forestry, fisheries and wildlife management. The potential risks with restocking of native species has for a long time been overshadowed by the related issue of invasive species. However, during the last decade releases of native species with a potential non-native genome have attained more attention. A suitable model species for studying genetic effects of large-scale releases of a native species is the Mallard, Anas platyrhynchos; it is the most widespread duck in the world, it is a migrating species, and an important game bird. In several European countries it is also farmed and released to increase the harvestable population, and more than 3 million unfledged hatchlings are released each year around Europe. The aims of this study were to determine if wild and released farmed Mallards differed genetically among subpopulations in Europe, if there are signs of previous or ongoing introgression between wild and farmed Mallards, and if the genetic structure of the wild Mallard population has changed since large-scale releases started in the 1970s. We used 360 Single Nucleotide Polymorphisms (SNPs) to analyze the genetic structure of historical wild, present-day wild, and farmed Mallards. We found a clear genetic difference between wild and farmed Mallards in Europe. We also found signs of introgression of farmed genes in the wild Mallard population, however, the rate of hybridization is probably minor due to low survival of released farmed Mallards and a change of the wild population since the start of large-scale releases is therefore limited. A low level of hybridization between farmed and wild Mallard is desired as introgressed genes may be detrimental for wild Mallards, and efforts to increase survival of farmed Mallards should therefore not be encouraged.
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| 10. |
- Söderquist, Pär, et al.
(författare)
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Released gamebrds cause introgression in European mallard
- 2015
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Ingår i: 4th Pan-European Duck Symposium, Hangö, Finland. ; , s. 75-
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Konferensbidrag (refereegranskat)abstract
- The practice of restocking already viable populations to improve harvest has since long been common in forestry, fisheries and wildlife management. The potential risks with restocking of native species has for a long time been overshadowed by the related issue of invasive species. However, during the last decade releases of native species with a potential non-native genome have attained more attention. A suitable model species for studying genetic effects of large-scale releases of a native species is the Mallard, Anas platyrhynchos; it is the most widespread duck in the world, it is a migrating species, and an important game bird. In several European countries it is also farmed and released to increase the harvestable population, and more than 3 million unfledged hatchlings are released each year around Europe. The aims of this study were to determine if wild and released farmed Mallards differed genetically among subpopulations in Europe, if there are signs of previous or ongoing introgression between wild and farmed Mallards, and if the genetic structure of the wild Mallard population has changed since large-scale releases started in the 1970s. We used 360 Single Nucleotide Polymorphisms (SNPs) to analyze the genetic structure of historical wild, present-day wild, and farmed Mallards. We found a clear genetic difference between wild and farmed Mallards in Europe. We also found signs of introgression of farmed genes in the wild Mallard population, however, the rate of hybridization is probably minor due to low survival of released farmed Mallards and a change of the wild population since the start of large-scale releases is therefore limited. A low level of hybridization between farmed and wild Mallard is desired as introgressed genes may be detrimental for wild Mallards, and efforts to increase survival of farmed Mallards should therefore not be encouraged.
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