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Full-Text Articles in Chemistry
Resin Volatiles Of Eastern Hemlock Induced By Its Non-Native Herbivores, Joshua D. Pezet
Resin Volatiles Of Eastern Hemlock Induced By Its Non-Native Herbivores, Joshua D. Pezet
Masters Theses 1911 - February 2014
Eastern hemlock (Tsuga canadensis) is in decline because of infestation by the invasive hemlock woolly adelgid (Adelges tsugae; ‘HWA’) and, to a lesser extent, the elongate hemlock scale (Fiorinia externa; ‘EHS’). Many conifers respond to insect herbivory by inducing oleoresin-based defenses, however it is unknown whether eastern hemlock is capable of this inducible response. We conducted a plantation setting study of artificially infested saplings to determine if feeding by HWA or EHS induces changes in the tree’s volatile chemistry. The induced changes in volatiles we found were unlike the terpenoid-based defenses of related conifers. Only HWA feeding …
Nitrogen Dioxide In The Urban Forest: Exposure And Uptake, Tanner B. Harris
Nitrogen Dioxide In The Urban Forest: Exposure And Uptake, Tanner B. Harris
Masters Theses 1911 - February 2014
Nitrogen dioxide (NO2) levels were measured inside and adjacent to canopies of urban trees in Springfield, MA, over two growing seasons. Nitrogen dioxide levels were consistently and significantly higher inside tree canopies compared to levels outside. During the second growing season, ozone (O3), temperature, and relative humidity (RH) were also measured using samplers co-located with the NO2 samplers. Ozone levels were significantly lower inside the canopy whereas temperatures were higher inside the canopy, and RH was not different between inner and outer canopy locations. The results corroborate theoretical models predicting elevated NO2 and depressed O3 levels inside tree canopies based …