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A boreal invasion in response to climate change? Range shifts and community effects in the borderland between forest and tundra.

Elmhagen B, Kindberg J, Hellström P, Angerbjörn A - Ambio (2015)

Bottom Line: However, in addition to climate warming, suggested drivers of change include land use and other anthropogenic factors.We hypothesize all these drivers interacted, primarily favoring southern generalists.Future research should aim to distinguish between effects of climate and land-use change in boreal and tundra ecosystems.

View Article: PubMed Central - PubMed

Affiliation: Department of Zoology, Stockholm University, 106 91, Stockholm, Sweden, bodil.elmhagen@zoologi.su.se.

ABSTRACT
It has been hypothesized that climate warming will allow southern species to advance north and invade northern ecosystems. We review the changes in the Swedish mammal and bird community in boreal forest and alpine tundra since the nineteenth century, as well as suggested drivers of change. Observed changes include (1) range expansion and increased abundance in southern birds, ungulates, and carnivores; (2) range contraction and decline in northern birds and carnivores; and (3) abundance decline or periodically disrupted dynamics in cyclic populations of small and medium-sized mammals and birds. The first warm spell, 1930-1960, stands out as a period of substantial faunal change. However, in addition to climate warming, suggested drivers of change include land use and other anthropogenic factors. We hypothesize all these drivers interacted, primarily favoring southern generalists. Future research should aim to distinguish between effects of climate and land-use change in boreal and tundra ecosystems.

No MeSH data available.


Related in: MedlinePlus

Northern expansion of four southern species (red) in the northernmost Swedish counties (a–c), indicated by hunting bags for 1960–2010, compared to similar northern or already established species (gray). The western jackdaw (Corvus monedula) was one of the expanding southern bird species (Table 1). Hunting bag data were provided by the Swedish Association for Hunting and Wildlife Management
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Fig3: Northern expansion of four southern species (red) in the northernmost Swedish counties (a–c), indicated by hunting bags for 1960–2010, compared to similar northern or already established species (gray). The western jackdaw (Corvus monedula) was one of the expanding southern bird species (Table 1). Hunting bag data were provided by the Swedish Association for Hunting and Wildlife Management

Mentions: Early reports attribute low abundance of hare and grouse to unfavorable weather and disease, but increased fox predation is mentioned twice in the 1920s (Sweden’s Official Statistics 1870–1966). At present, the dominant hypothesis suggests that 3–5-year cycles in medium-size herbivores are caused by medium-sized predators, which switch from rodent prey to medium-sized prey in the decrease phase of the rodent cycle (Angelstam et al. 1985; Kausrud et al. 2008). The tendency for 10-year fluctuations in mountain hare might be caused by interactions with larger predators, similar to present-day mountain hare populations in Russian Karelia which fluctuate with an approximate 11-year period tracked by the Eurasian lynx (Lynx lynx; Danilov 2010). In Sweden, strong suppression of medium-sized herbivores by red fox predation is supported by a temporary increase in hare and boreal grouse in the 1980s when a mange epizootic reduced the fox population (Fig. 3; Danell and Hörnfeldt 1987; Lindström et al. 1994). Red fox expansion in alpine Sweden is one potential cause of decline in white-fronted goose (Svensson et al. 1999). In Finland, boreal grouse is negatively affected by forestry, climate change, and fox predation (Ludwig 2007). In southern Sweden, the mountain hare has declined due to interference with introduced brown hares (Lepus europaeus). Since 1980, the brown hare has advanced north into boreal Sweden, likely in response to mild winters (Fig. 3; Jansson and Pehrson 2007).Fig. 3


A boreal invasion in response to climate change? Range shifts and community effects in the borderland between forest and tundra.

Elmhagen B, Kindberg J, Hellström P, Angerbjörn A - Ambio (2015)

Northern expansion of four southern species (red) in the northernmost Swedish counties (a–c), indicated by hunting bags for 1960–2010, compared to similar northern or already established species (gray). The western jackdaw (Corvus monedula) was one of the expanding southern bird species (Table 1). Hunting bag data were provided by the Swedish Association for Hunting and Wildlife Management
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4289007&req=5

Fig3: Northern expansion of four southern species (red) in the northernmost Swedish counties (a–c), indicated by hunting bags for 1960–2010, compared to similar northern or already established species (gray). The western jackdaw (Corvus monedula) was one of the expanding southern bird species (Table 1). Hunting bag data were provided by the Swedish Association for Hunting and Wildlife Management
Mentions: Early reports attribute low abundance of hare and grouse to unfavorable weather and disease, but increased fox predation is mentioned twice in the 1920s (Sweden’s Official Statistics 1870–1966). At present, the dominant hypothesis suggests that 3–5-year cycles in medium-size herbivores are caused by medium-sized predators, which switch from rodent prey to medium-sized prey in the decrease phase of the rodent cycle (Angelstam et al. 1985; Kausrud et al. 2008). The tendency for 10-year fluctuations in mountain hare might be caused by interactions with larger predators, similar to present-day mountain hare populations in Russian Karelia which fluctuate with an approximate 11-year period tracked by the Eurasian lynx (Lynx lynx; Danilov 2010). In Sweden, strong suppression of medium-sized herbivores by red fox predation is supported by a temporary increase in hare and boreal grouse in the 1980s when a mange epizootic reduced the fox population (Fig. 3; Danell and Hörnfeldt 1987; Lindström et al. 1994). Red fox expansion in alpine Sweden is one potential cause of decline in white-fronted goose (Svensson et al. 1999). In Finland, boreal grouse is negatively affected by forestry, climate change, and fox predation (Ludwig 2007). In southern Sweden, the mountain hare has declined due to interference with introduced brown hares (Lepus europaeus). Since 1980, the brown hare has advanced north into boreal Sweden, likely in response to mild winters (Fig. 3; Jansson and Pehrson 2007).Fig. 3

Bottom Line: However, in addition to climate warming, suggested drivers of change include land use and other anthropogenic factors.We hypothesize all these drivers interacted, primarily favoring southern generalists.Future research should aim to distinguish between effects of climate and land-use change in boreal and tundra ecosystems.

View Article: PubMed Central - PubMed

Affiliation: Department of Zoology, Stockholm University, 106 91, Stockholm, Sweden, bodil.elmhagen@zoologi.su.se.

ABSTRACT
It has been hypothesized that climate warming will allow southern species to advance north and invade northern ecosystems. We review the changes in the Swedish mammal and bird community in boreal forest and alpine tundra since the nineteenth century, as well as suggested drivers of change. Observed changes include (1) range expansion and increased abundance in southern birds, ungulates, and carnivores; (2) range contraction and decline in northern birds and carnivores; and (3) abundance decline or periodically disrupted dynamics in cyclic populations of small and medium-sized mammals and birds. The first warm spell, 1930-1960, stands out as a period of substantial faunal change. However, in addition to climate warming, suggested drivers of change include land use and other anthropogenic factors. We hypothesize all these drivers interacted, primarily favoring southern generalists. Future research should aim to distinguish between effects of climate and land-use change in boreal and tundra ecosystems.

No MeSH data available.


Related in: MedlinePlus