Easternwhitepine(PinusstrobusL.)isawidespreadconiferineasternNorthAmerica.Anoveldiebackphenomenon,aswellas increasingglobaltemperaturescontributingtothecontractionofsuitablehabitat,isthreateningthisspecies’long-termpersistence in the Southern Appalachian Mountains. This southern extent of its current range is where P. strobus is hypothesized to have survived in refugial populations during the last glacial maximum. As a result, extant populations located here may have higher levelsofancestral genetic diversity, and byextension, adaptivepotential.We genotyped 432 P.strobusindividuals from23sites throughouttheSouthernAppalachiansandanother34individualsfromtworeferencepopulationsinthenorthernUSA,using10 establishedmicrosatellitemarkers.Levelsofgeneticdiversityinthesouthernportionoftherangewerecomparablebutnothigher thanreferencenorthernpopulations.Therewasanoverallheterozygotedeficiencyandhighinbreedingcoefficient(FIS=0.173); however,thesevalueswerecomparabletopublishedresearchofP.strobusthroughoutthenorthernrange.Therewaslowoverall genetic differentiation (FST=0.055) among populations in the Southern Appalachians and population structure was best explained by ecoregions. These results show that P. strobus in the Southern Appalachians is a fairly heterogenous and admixed species with relatively high genetic diversity mostly partitioned within populations. The Southern Appalachians remains an important area for P. strobus conservation, but not necessarily because it is genetically unique.
Whitney, Thomas D.; Gandhi, Kamal J. K.; Hamrick, J. L.; Lucardi, Rima D. 2019. Extant population genetic variation and structure of eastern white pine (Pinus strobus L.) in the Southern Appalachians. Tree Genetics & Genomes. 15(5): 967-. https://doi.org/10.1007/s11295-019-1380-3.