Phylogeography of white spruce ( Picea glauca) in eastern North America reveals contrasting ecological trajectories

• Published in: Journal of Biogeography
• Main Authors: de Lafontaine, Guillaume, Turgeon, Julie, Payette, Serge
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2010
• Subjects: Tundra
• Online Access: http://dx.doi.org/10.1111/j.1365-2699.2009.02241.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1365-2699.2009.02241.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-2699.2009.02241.x

Abstract Aim The main objective of this study was to investigate the origin of white spruce ( Picea glauca ) range discontinuities in eastern North America. A first analysis aimed at uncovering the glacial origin and post‐glacial migration route of white spruce in the eastern part of the range. A second analysis aimed at evaluating whether disjunct white spruce populations in central Québec result from a recent expansion or are remnant stands following a northern range contraction. Location The first analysis covered the North American transcontinental boreal distribution of white spruce, and the second focused on the eastern part of its range. Methods A total of 589 P. glauca individuals from 51 populations, 24 of which were from a previous published source, were analysed for variation in three chloroplast DNA regions ( trn T/L, trn L/F and ndh K/C). At the continental scale, haplotypic diversity, zones of genetic discontinuities, clustering analysis and analysis of molecular variance (AMOVA) were employed. In the eastern part of the range, haplotypic diversity was assessed with a permutation procedure, demographic history with mismatch analyses, and genetic structure with AMOVA. Results At the continental scale, various lines of evidence (genetic‐diversity hotspots, endemic haplotypes, zones of genetic discontinuities, and pattern of molecular variation) show that different lineages migrated from three glacial refugia (Beringian, Mississippian, east Appalachian). Strong genetic discontinuities, low diversity and lack of evidence for demographic expansion were found among stands from isolated high hills in central Québec. Main conclusions White spruce in the eastern part of its range has an east Appalachian origin, a lineage genetically distinct from populations west of the Great Lakes. Previous studies have shown that the northward migration of white spruce is still ongoing as the northernmost populations expand into the tundra. In contrast, mixed white spruce and balsam fir ( Abies balsamea ) stands from ...