ORCID ID

0000-0001-9416-9226

Date Awarded

2018

Document Type

Thesis

Degree Name

Master of Science (M.Sc.)

Department

Biology

Advisor

Joshua Puzey

Committee Member

Harmony Dalgleish

Committee Member

Helen Murphy

Abstract

All organisms must interact with and adapt to their surrounding environment. There are myriad ways in which species accomplish this; ultimately resulting in the vast diversity of life on earth today. Changes in the environment can have profound impacts on an organisms' ability to compete and utilize their surroundings. Plants are particularly impacted by local environmental differences because of the fact that they are immobile. This environmental variation exists at both large and small spatial scales. For example, on larger scales, forces such as fire and grazers can remove dominant plant competitors. on smaller scales, variation in resource availability (e.g. light, nutrients, water) may benefit more phenotypically plastic species. to better understand how changes in the environment, on both large and small spatial scales, I established a two part study using milkweed (Asclepias spp.) as a model system. in the first chapter, I ask how fire, large grazers, and nutrients have affected milkweed abundance over relatively long time and large spatial scales. Here I found that most milkweed species increase in abundance with burning alone but expressed species-specific responses to other treatment combinations. This indicates that milkweed species have likely experienced unique fluctuations in abundance as fire and large herbivores moved across the landscape. The second aspect of this research focuses in on a single year and relatively small spatial scales. Here, using common milkweed (A. syriaca), I ask how environmental variation shapes spatial structuring of phenotypes within fine-scale physical distance and how genotypes impact phenotypes. I found that environment, not genotype, had a relatively larger role on fine-scale phenotypic variation. Combined, these results have implications for understanding the role of large and small scale environmental variations in plant phenotypes and plant abundance.

DOI

http://dx.doi.org/10.21220/s2-dxw3-sr51

Rights

© The Author

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Biology Commons

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