Date of Award
Master of Science
The hemlock-silverbell (Tsuga canadensis-Halesia tetraptera) forest type is known to exist in only two places, the Great Smoky Mountains National Park (GRSM) and the Joyce Kilmer National Memorial Forest. The hemlock component of this forest type is currently threatened by the hemlock woolly adelgid (Adelgis tsugae), an invasive aphid-like insect native to Japan. This current status has given rise to the need to investigate the ecological resources of this rare forest type before the hemlock component dies out. The objectives of this study were to determine the nature of the plant/environment and plant/plant associations within this forest type. Within this forest type hemlock was negatively related to protection, aspect, and slope steepness and silverbell was positively related to aspect and slope steepness. This study also identified some interspecific associations such as the negative relationship in the understory between hemlock and striped maple, and provided evidence that understory stems are exhibiting a growth response to hemlock decline in these stands. The information obtained from this study characterizing the plant/environment interactions and even the structural and species components of this forest type will serve as a baseline of data from which to measure change and will provide insight into the mechanisms of species distribution and perhaps into short term scenarios of forest response to hemlock decline and mortality.
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