Creative Commons License

Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.

Date of Award

Summer 2016

Document Type


Degree Name

Master of Science (MS)


Department of Biology


Heather Griscom


Shenandoah National Park (SNP) contains over 20,000 eastern hemlocks (Tsuga canadensis); a foundation species in the southern Appalachian Mountains. Hemlock is shade-tolerant and retains a dense needle canopy year-round, creating a unique microclimate providing habitat for many species. The decline in eastern hemlock from hemlock woolly adelgid (Adelges tsugae; HWA) infestation has negative implications for the overall function of forest ecosystems. The effect of slope aspect and time since imidacloprid insecticide treatment on crown health change and diameter growth of eastern hemlock in SNP was quantified. Data was compared from hemlock trees located on southeastern (SE) and northwestern (NW) aspects at sites that were either treated two, five or eight years ago. Trees at control sites received no treatment. Change in crown health was significantly affected by aspect and time since treatment (p