Semester

Fall

Date of Graduation

2007

Document Type

Thesis

Degree Type

MS

College

Davis College of Agriculture, Natural Resources and Design

Department

Wood Science and Technology

Committee Chair

Eric Heitzman.

Abstract

Cathedral State Park (CSP) is a 54-ha, old-growth, hemlock-hardwood forest located in the central Appalachian Mountains of West Virginia. Trees larger than 100 cm diameter at breast height (dbh) and 35 m tall are common. Hemlock woolly adelgid (HWA) (Adelges tsugae Annand) is an exotic insect that currently threatens eastern hemlock (Tsuga canadensis (L.) Carr.) throughout its native range, and was found in CSP in 2002. In 2006, field plots established in 2000 were remeasured to assess adelgid-induced changes to forest structure and species composition. The herbaceous plant community was also measured during the 2006 growing season to describe how the ground flora has changed since it was originally surveyed in 1965. In addition, snag density, snag basal area, and the volume of downed dead wood in CSP were compared to 25 similar old-growth hemlock-hardwood stands in the eastern United States. From 2000 to 2006 relatively little change occurred in woody vegetation in CSP. However, more than 10% of overstory hemlocks measured were identified with HWA, with plot infestations ranging from 0-93%. Currently, no hemlock mortality can be attributed to HWA, but many trees already show symptoms of infestation. The ground flora has remained relatively unchanged since it was originally sampled, with the most common species in 1965 still prevalent in 2006. Snag basal area was similar (p=0.86) to 25 comparable old-growth hemlock-hardwood stands, although less than half the snag density (p<0.001) was found in CSP. CSP also had more than twice the volume of logs ≥20 cm mid-point diameter compared to other old-growth hemlock-hardwood stands. This study serves as a reference of forest structure and species composition in CSP prior to HWA-induced mortality.

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