Abstract Detail

Molecular Ecology

Stunz, Elizabeth [1], Fetcher, Ned [2], Mohl, Jonathon [3], Moody, Michael [4].

Population structure, demographics and local adaptation of the arctic dwarf birch (Betula nana) in relation to the arctic tussock cottongrass (Eriophorum vaginatum) in north central Alaska.

Increase in shrub cover is a major effect of ongoing climate change in arctic tundra ecosystems. Relative increases in shrub abundance and cover of species such as birch, willow, and alder (Betula, Salix, and Alnus spp.) are predicted to alter ecological communities by modifying biodiversity and ecosystem processes. Shrub species like the dwarf birch (Betula nana L.; Betulaceae) have been shown to respond quickly and outcompete other arctic plant species with increased air temperature and nutrient availability. An aggressive competitor, B. nana reproduces clonally and sexually and has the potential to drastically alter dynamics of the moist tundra ecosystem if it becomes more prevalent and displaces tussock cottongrass (Eriophorum vaginatum L.; Cyperaceae), the currently dominant plant species. We used double-digest Restriction Site-Associated DNA sequencing (ddRAD-seq) to identify genomic variation in 101 individuals of B. nana from 9 sites along a latitudinal gradient in north central Alaska. Sites were chosen to overlap with those that we used in a landscape genomics study of E. vaginatum and have ddRAD-seq SNP data for, and are inclusive of a region that was part of the Beringian refugium. Long-term studies and genomic studies now suggest differentiation due to older and contemporary gene flow barriers as well as adaptation for E. vaginatum in this region. While this has not been examined for B. nana, we expect similar structure as both species are wind-dispersed and wind-pollinated. Investigation of genomic population structure, genetic diversity, and demographic modeling will increase understanding of the rate at which B. nana will be able to expand its range and potentially displace E. vaginatum.

1 - 4411 Trowbridge Dr, El Paso, TX, 79903, United States
2 - Wilkes University, Biological Sciences, 84 W South St, Wilkes-Barre, PA, 18766, USA
3 - University of Texas at El Paso, Mathematical Sciences and the Border Biomedical Research Center, 500 W University Ave, El Paso, TX, 79968, USA
4 - University Of Texas At El Paso, Dept. Of Biological Sciences, 500 W. University Ave., El Paso, TX, 79968.0, United States

Keywords:
arctic
climate change
landscape genomics
Betula nana
Eriophorum vaginatum
environmental niche modeling
Refugia.

Presentation Type: Oral Paper
Number: ME3004
Abstract ID:597
Candidate for Awards:None