Skip to Main Content
Ethanol accumulation during severe drought may signal tree vulnerability to detection and attack by bark beetlesAuthor(s): Rick G. Kelsey; D. Gallego; F.J. Sánchez-Garcia; J.A. Pajares
Source: Canadian Journal of Forestry Research
Publication Series: Scientific Journal (JRNL)
Station: Pacific Northwest Research Station
View PDF (0 B)
DescriptionTree mortality from temperature-driven drought is occurring in forests around the world, often in conjunction with bark beetle outbreaks when carbon allocation to tree defense declines. Physiological metrics for detecting stressed trees with enhanced vulnerability prior to bark beetle attacks remain elusive. Ethanol, water, monoterpene concentrations, and composition were examined in the phloem and sapwood of drought-stressed Aleppo pine (Pinus halepensis Mill.) freshly attacked by mature Mediterranean pine shoot beetles (Tomicus destruens (Wollaston, 1865)) and in neighboring unattacked trees. The attacked trees were more water-stressed and contained, on average, 2.1 and 2.4 times more ethanol in the phloem and sapwood, respectively, than the neighboring attack-free trees. This response is consistent with the known attraction of T. destruens to ethanol. Most monoterpene concentrations in the phloem, but not sapwood, were greater in tissues of attacked trees, whereas compositional differences were minor between the two tree groups for both tissues. Tissue water content explained much of the variation in phloem monoterpene concentrations, which increased as water in the phloem declined, suggesting that higher constitutive quantities existed in themore stressed trees prior to the attacks. Monoterpenes may have contributed to host tree selection by T. destruens, but their potential influence is considered less important than that of ethanol based on beetle responses to these compounds in previous trapping studies. This is the first report of elevated ethanol concentrations in tissues of trees experiencing natural drought stress and suggests that ethanol measurements in severely water-stressed trees may allow early detection of those most vulnerable to bark beetle attack.
- You may send email to email@example.com to request a hard copy of this publication.
- (Please specify exactly which publication you are requesting and your mailing address.)
- We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
CitationKelsey, Rick G.; Gallego, D.; Sánchez-Garcia, F.J.; Pajares, J.A. 2014. Ethanol accumulation during severe drought may signal tree vulnerability to detection and attack by bark beetles. Canadian Journal of Forestry Research. 44: 554-561.
Keywordswater stress, ethanol, Tomicus destruens, Pinus halepensis, host selection.
- What do cocktail parties and stressed trees have in common? Plenty of alcohol!
- Ethanol accumulation in drought-stressed conifer seedlings
- Ethanol and acetone from Douglas-fir roots stressed by Phellinus sulphurascens infection: Implications for detecting diseased trees and for beetle host selection
XML: View XML