Kristin BuchnerAppalachian State University

Research and Creative Endeavors DayApril 23, 2009

Organic hydrocarbon compoundsComposed of isoprene unitsSecondary metabolitesEmitted into the environment through leaching,

volatilization, or decomposition

In nature: Attract/repel insectsDeter other competitive plants

In Industry: (“essential oils”)Flavor additives/enhancersFragrancesAlternative medicineCleaning agents (pine-sol)

Optimal Defense Theory Growth-Differentiation Balance hypothesis

Diagram taken from Hamilton et al., 2001

Old-Field Community Climate and Atmospheric Manipulation (OCCAM)

Solidago canadensis

3 climate drivers:Elevated and ambient [CO2]Elevated and ambient temperatureAmbient and low water supply

How will terpene concentration be affected?

48 samples were collected in June 2008 from the OCCAM site at ORNL in Oak Ridge, TN

Gas Chromatography AnalysisP-value ≤ 0.10

24 samples collected from Dale Cornett's Carolina Fraser Fir Farm in Vilas, NC, on December 8, 2008

Samples taken from damaged and healthy areas of each Fir exhibiting Balsam Twig Aphid damage

P-value ≤0.05

Special thanks to the North Carolina Agricultural Extension for their support with this project.

tree damagetree x

damage

-pinene 0.2897 0.0075 0.2127

β-pinene <0.0001 0.5692 0.1618

limonene <0.0001 0.0135 0.1404C1 <0.0001 0.031 0.8486C2 0.0003 0.1335 0.6021C3 <0.0001 0.2338 0.0145C4 0.0008 0.0004 0.531

Carbon allocation?Growth and repair vs. terpenes

Improved defenses?Pre-emptive prevention or genetic resistance

Overcompensation?Plants respond with a flood of defenses

Plant tissue age?Older leaves could have lower defenses

Langenheim, J.H.: 1994, 'Higher-Plant Terpenoids - a Phytocentric Overview of Their Ecological Roles', Journal of Chemical Ecology 20, 1223-1280.

Hamilton, J.G., Zangerl, A.R., DeLucia, E.H. and Berenbaum, M.R.: 2001, 'The carbon-nutrient balance hypothesis: its rise and fall', Ecology Letters 4, 86-95.

Sidebottom, J.: 2002, ‘Balsam Twig Aphid on Fraser Fir: CTN-019’, Extension Forestry, North Carolina State University.

Villalpando, S.N., Williams, R.S. and Norby, R.J.: 2009, 'Elevated air temperature alters an old-field insect community in a multifactor climate change experiment', Global Change Biology 15, 930-942.

Williams, R.S., Thomas, R.B., Strain, B.R. and Lincoln, D.E.: 1997, 'Effects of elevated CO2, soil nutrient levels, and foliage age on the performance of two generations of Neodiprion lecontei (Hymenoptera : Diprionidae) feeding on loblolly pine', Environmental Entomology 26, 1312-1322.