Semester

Summer

Date of Graduation

2009

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

We examined the attributes of canopy gaps on the 3,100 ha West Virginia University Research Forest (WVURF) near Morgantown, WV. The WVURF is a 70-80 year-old, second-growth, Appalachian hardwood forest. The objectives of this study were: (1) to describe specific gap characteristics (size, age, and fraction) of the forest as a whole, and (2) to assess whether gap characteristics varied by slope position (cove, mid, ridge), aspect (NE, NW, SE, SW), and forest cover type (cove hardwood, mesic oak, xeric oak).;Transect lines were digitized using GIS in ArcMap and systematically placed throughout the forest to include a range of aspects and slope positions. Sixty-one transects were established, with a total length of 22,508 m. Line intersect sampling was used to select gaps. Eighty gaps were identified. The average gap size was 98.59 (+/-134.17) m2. The average expanded gap size was 287.64 (+/-238.49) m2. Gap age ranged from 2-29 years old with a mean age of 16.42 (+/-6.3) years. Overall, 2.73 (+/-2.48) % of the forest was composed of gaps. These figures are small compared to old growth forests in the region. WVURF is a young forest, therefore the gaps created are relatively small and scattered. We speculate the WVURF remains in the late stem exclusion to early understory re-initiation stage.;There were no differences in gap size by aspect or slope position. Cove hardwoods had larger gap sizes than mesic and xeric oak. Expanded gaps were also largest in cove hardwoods and on northwest and southeast aspects. There were no differences in gap age based on slope position, aspect, or forest type. Gap fraction did not differ by slope position, but gap fraction was greatest on southeast slopes and in cove hardwoods.;Regeneration within gaps included a variety of species including oaks (Quercus sp.), black cherry (Prunus serotina), black birch (Betula lenta), maple (Acer sp.), and understory shrubs. Oak regeneration importance values did not vary by aspect or forest type, but were significantly higher in coves and mid-slopes than on ridges. Almost two-thirds of gap-makers, trees whose death created the gap, were oaks.;Understanding the disturbance dynamics, especially the canopy gap dynamics, of second growth forests is important in the development of ecosystem management policies. The framework advanced by this study could aid land managers in implementing informed management policies and practices that more closely resemble the natural disturbances that are occurring in the WVURF.

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