Date of Defense

4-19-2019

Date of Graduation

4-2019

Department

Biological Sciences

First Advisor

Steven Bertman

Second Advisor

Todd Barkman

Abstract

Climate changes is one of the most serious threats facing the future of our planet, and with is we will see drastic changes to water levels global temperatures, and atmospheric conditions. Modeling future atmospheric conditions is crucial if we are to plan for and mitigate the consequences of climate change – while important, these models will not be useful to future scientists unless various parameters, such as BVOC emission to the atmosphere, are accounted for and included in computer models. Eastern white pine (Pinus strobus) are predicted to be a major component of future climax forests as their abundance increases naturally with succession, and they have the ability to tolerate dry and sandy soils. Because of this, it is important to understand what parameters effect BVOC (in the form of volatile terpenes) concentration in the needles of white pine. Previous investigation at the University of Michigan Biological Station in Pellston, MI indicated that understory white pine located in plots of forest experiencing disturbance (in the form of selective stem girdling of early successional species) had elevated levels of one compound, germacrene D-4-ol, in comparison to trees located in a control forest. This compound is interesting as it is structurally different from other terpene components of the pine’s needle extract; this compound is a terpene-alcohol. Because of this, and due to its large concentration in the needles, it is important that the chemical properties of this compound be known to accurately predict emissions to the atmosphere, and therefore aid in future climate modeling. This poses a unique challenge as germacrene D-4-ol has no known commercially available standard, has uncharacterized chemical properties, and is not identified in feasible manners in the extracts of other plants. Because of the importance of characterizing the compound, this study set out to isolate the compound from the needles of Eastern white pine, characterize its structure and chemical properties, and propose a potential physiological role of the compound in the tree. Several different isolation techniques were attempted including gravity column isolation, liquid-liquid extraction, solid-phase extraction, and preparatory gas-chromatography. None of the methods that were tried were able to separate the compound from another unknown present in large quantities in the needles. A literature search confirmed that no commercially available standard exists, and that the compound has been tentatively reported to exist in at least 38 different species. This highlights the importance of this research and suggests that a purified standard could be of benefit to climate change scientists, chemists, ecologists, and botanists alike.

Access Setting

Honors Thesis-Open Access

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