Date of Award

2022-12-01

Degree Name

Doctor of Philosophy

Department

Biological Sciences

Advisor(s)

Michael L. Moody

Abstract

Global climate change has resulted in geographic range shifts of flora and fauna at a global scale. Extreme environments, like the Arctic, are seeing some of the most pronounced changes. This region covers 14% of the Earthâ??s land area, and while many arctic species are widespread, understanding ecotypic variation at the genomic level will be important for elucidating how range shifts will affect ecological processes. Increase in shrub cover is a major effect of ongoing climate change in arctic tundra ecosystems. The relative increases in abundance and cover of shrub species such as birch, willow, and alder (Betula, Salix, and Alnus spp.) are predicted to modify ecological communities by altering ecosystem processes and outcompeting other arctic plant species, such as the tussock cottongrass (Eriophorum vaginatum L.). Eriophorum vaginatum is a foundation species of the moist acidic tundra, whose potential decline due to competition from shrubs may affect ecosystem stability in the Arctic. Here, I examine the genomic population structure, local adaption, and genotype-environment associations of two widespread arctic plant species, the tussock cottongrass (Eriophorum vaginatum) and the dwarf birch (Betula nana L.) using thousands of genomic markers obtained from double-digest Restriction-site Associated DNA sequencing (ddRAD-seq). I then compare environmental niche models for both species from the Last Glacial Maximum (LGM) to the year 2070 to examine the potential of range expansion and persistence of each species in a warming arctic.

Language

en

Provenance

Received from ProQuest

File Size

182 p.

File Format

application/pdf

Rights Holder

Elizabeth Stunz

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