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Genetic evidence for restricted dispersal along continuous altitudinal gradients in a climate change-sensitive mammal: the American Pika.

Henry P, Sim Z, Russello MA - PLoS ONE (2012)

Bottom Line: We found low levels of neutral genetic variation compared to previous studies from more southerly latitudes, consistent with the relatively recent post-glacial colonization of the study location.Moreover, significant levels of inbreeding and marked genetic structure were detected within and among sites.Changes in climatic regimes forecasted for the region may thus potentially increase the rate of population extirpation by further reducing dispersal between sites.

View Article: PubMed Central - PubMed

Affiliation: Department of Biology, University of British Columbia, Okanagan campus, Kelowna, British Columbia, Canada.

ABSTRACT
When faced with rapidly changing environments, wildlife species are left to adapt, disperse or disappear. Consequently, there is value in investigating the connectivity of populations of species inhabiting different environments in order to evaluate dispersal as a potential strategy for persistence in the face of climate change. Here, we begin to investigate the processes that shape genetic variation within American pika populations from the northern periphery of their range, the central Coast Mountains of British Columbia, Canada. At these latitudes, pikas inhabit sharp elevation gradients ranging from sea level to 1500 m, providing an excellent system for studying the effects of local environmental conditions on pika population genetic structure and gene flow. We found low levels of neutral genetic variation compared to previous studies from more southerly latitudes, consistent with the relatively recent post-glacial colonization of the study location. Moreover, significant levels of inbreeding and marked genetic structure were detected within and among sites. Although low levels of recent gene flow were revealed among elevations within a transect, potentially admixed individuals and first generation migrants were identified using discriminant analysis of principal components between populations separated by less than five kilometers at the same elevations. There was no evidence for historical population decline, yet there was signal for recent demographic contractions, possibly resulting from environmental stochasticity. Correlative analyses revealed an association between patterns of genetic variation and annual heat-to-moisture ratio, mean annual precipitation, precipitation as snow and mean maximum summer temperature. Changes in climatic regimes forecasted for the region may thus potentially increase the rate of population extirpation by further reducing dispersal between sites. Consequently, American pika may have to rely on local adaptations or phenotypic plasticity in order to survive predicted climate changes, although additional studies are required to investigate the evolutionary potential of this climate change sensitive species.

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Related in: MedlinePlus

Map of the study area in the Bella Coola Valley, British Columbia, Canada, with the ten sampling sites located along three altitudinal gradients (lowest and highest elevations indicated): the Hill, Nusatsum and Bentinck from east to west.The light shading indicates Tweedsmuir South Provincial Park. The inset on the top left indicates the distribution of O. princeps subspecies.
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pone-0039077-g001: Map of the study area in the Bella Coola Valley, British Columbia, Canada, with the ten sampling sites located along three altitudinal gradients (lowest and highest elevations indicated): the Hill, Nusatsum and Bentinck from east to west.The light shading indicates Tweedsmuir South Provincial Park. The inset on the top left indicates the distribution of O. princeps subspecies.

Mentions: This study was carried out in the Bella Coola Valley, BC (Fig. 1). This area was initially chosen because historical records show the presence of O. princeps from sea level to tree line and the presence of an extensive network of roads connecting the bottom of the valley to higher elevations. In this study area, talus slopes are highly fragmented and scattered throughout the landscape at relatively larger distances from each other (1 km to >70 km; Table S1). American pikas were sampled from August 2008 to September 2010 at 10 sites along three elevation gradients ranging from sea level to 1500 m using recently developed noninvasive hair snares (Fig. 1) [14], [15], and following the animal care protocol from the University of British Columbia (Certificate number: A07-0126). Pikas at site A1 were potentially extirpated in the late summer of 2009 due to a forest fire that burned through the area, but the site was re-occupied as of summer 2011 (Michael Russello, personal communication). Samples were collected in sites B, C, D and E in 2008, 2009 and 2010, from site A1 in 2008 and 2009, and from sites A2, F, G, H and I in 2010. A total of 288 geo-referenced individual hair snares were set up across these ten sites (Fig. 1) and samples were brought back to the laboratory for subsequent DNA extraction and PCR amplification.


Genetic evidence for restricted dispersal along continuous altitudinal gradients in a climate change-sensitive mammal: the American Pika.

Henry P, Sim Z, Russello MA - PLoS ONE (2012)

Map of the study area in the Bella Coola Valley, British Columbia, Canada, with the ten sampling sites located along three altitudinal gradients (lowest and highest elevations indicated): the Hill, Nusatsum and Bentinck from east to west.The light shading indicates Tweedsmuir South Provincial Park. The inset on the top left indicates the distribution of O. princeps subspecies.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3376113&req=5

pone-0039077-g001: Map of the study area in the Bella Coola Valley, British Columbia, Canada, with the ten sampling sites located along three altitudinal gradients (lowest and highest elevations indicated): the Hill, Nusatsum and Bentinck from east to west.The light shading indicates Tweedsmuir South Provincial Park. The inset on the top left indicates the distribution of O. princeps subspecies.
Mentions: This study was carried out in the Bella Coola Valley, BC (Fig. 1). This area was initially chosen because historical records show the presence of O. princeps from sea level to tree line and the presence of an extensive network of roads connecting the bottom of the valley to higher elevations. In this study area, talus slopes are highly fragmented and scattered throughout the landscape at relatively larger distances from each other (1 km to >70 km; Table S1). American pikas were sampled from August 2008 to September 2010 at 10 sites along three elevation gradients ranging from sea level to 1500 m using recently developed noninvasive hair snares (Fig. 1) [14], [15], and following the animal care protocol from the University of British Columbia (Certificate number: A07-0126). Pikas at site A1 were potentially extirpated in the late summer of 2009 due to a forest fire that burned through the area, but the site was re-occupied as of summer 2011 (Michael Russello, personal communication). Samples were collected in sites B, C, D and E in 2008, 2009 and 2010, from site A1 in 2008 and 2009, and from sites A2, F, G, H and I in 2010. A total of 288 geo-referenced individual hair snares were set up across these ten sites (Fig. 1) and samples were brought back to the laboratory for subsequent DNA extraction and PCR amplification.

Bottom Line: We found low levels of neutral genetic variation compared to previous studies from more southerly latitudes, consistent with the relatively recent post-glacial colonization of the study location.Moreover, significant levels of inbreeding and marked genetic structure were detected within and among sites.Changes in climatic regimes forecasted for the region may thus potentially increase the rate of population extirpation by further reducing dispersal between sites.

View Article: PubMed Central - PubMed

Affiliation: Department of Biology, University of British Columbia, Okanagan campus, Kelowna, British Columbia, Canada.

ABSTRACT
When faced with rapidly changing environments, wildlife species are left to adapt, disperse or disappear. Consequently, there is value in investigating the connectivity of populations of species inhabiting different environments in order to evaluate dispersal as a potential strategy for persistence in the face of climate change. Here, we begin to investigate the processes that shape genetic variation within American pika populations from the northern periphery of their range, the central Coast Mountains of British Columbia, Canada. At these latitudes, pikas inhabit sharp elevation gradients ranging from sea level to 1500 m, providing an excellent system for studying the effects of local environmental conditions on pika population genetic structure and gene flow. We found low levels of neutral genetic variation compared to previous studies from more southerly latitudes, consistent with the relatively recent post-glacial colonization of the study location. Moreover, significant levels of inbreeding and marked genetic structure were detected within and among sites. Although low levels of recent gene flow were revealed among elevations within a transect, potentially admixed individuals and first generation migrants were identified using discriminant analysis of principal components between populations separated by less than five kilometers at the same elevations. There was no evidence for historical population decline, yet there was signal for recent demographic contractions, possibly resulting from environmental stochasticity. Correlative analyses revealed an association between patterns of genetic variation and annual heat-to-moisture ratio, mean annual precipitation, precipitation as snow and mean maximum summer temperature. Changes in climatic regimes forecasted for the region may thus potentially increase the rate of population extirpation by further reducing dispersal between sites. Consequently, American pika may have to rely on local adaptations or phenotypic plasticity in order to survive predicted climate changes, although additional studies are required to investigate the evolutionary potential of this climate change sensitive species.

Show MeSH
Related in: MedlinePlus