The Ecology and Management of Atlantic White Cedar (Chamaecyparis thyoides) 2012 SYMPOSIUM June 12, 13 and 14, 2012 Hilton Garden Inn on the waterfront in Suffolk, VA

Comparison of Harvesting and Fire on Atlantic white cedar (Chamaecyparis thyoides) Restoration through Floristic Composition in the Great Dismal Swamp National Wildlife Refuge (GDSNWR)

Jacqueline D. Roquemore and Robert B. Atkinson, Christopher Newport University, Center for Wetland Conservation

Jacqueline D. Roquemore, Christopher Newport University, Center for Wetland Conservation

Fire is a natural component of many ecosystems and a requirement for natural succession of Atlantic white cedar (AWC) swamps. Moist, peat soils of AWC swamps can provide a seed refugium. However, seeds may be destroyed if fire coincides with low water tables. Harvesting (salvage logging) can be used to simulate effects of stand-clearing fire, but environmental conditions may not be similar to fire-maintained stands. In natural areas, floristic composition is responsive to disturbance and can provide insight about difference in site conditions. The purpose of this study was to evaluate the effects of both salvage logging and fire on stand composition. In summer 1999 aerial cover of all herbaceous vascular species was measured in 54 1-m2 plots nested in 18 larger plots (3 nested subplots per plot) along a transect in a salvage-cut area in south GDSNWR. In summer 2010 aerial cover of all herbaceous vascular species was measured in 75 1-m2 plots adjacent to 25 plots (3 nested subplots per plot) that were burned in the GDS South One Fire in 2008. Plants were identified to species and Modified Importance Value (MIV) was calculated by summing relative cover and relative abundance (totals 200). Species richness in the salvage logging area (17 species) was lower than in the post-fire area (32 species). The Community Coefficient calculated with the Jaccard Similarity Index between the areas was 28.9% suggesting a large disparity in stand composition. The species with the highest MIV in the salvage logging stand was Toxicodendron radicans (36.6) and the species with the highest MIV in the post-burn area was Andropogon virginicus (34.9). The MIV of AWC was similar but low in both the salvage logging and the burned area (7.5 and 8.9, respectively) and was lower than reported for natural regenerating AWC swamps. The dissimilarity of floristic composition in the herbaceous layer of the two conditions is indicative of dissimilar environmental conditions. However, the comparable importance of AWC in the floristic compositions suggests that both salvage logging and fire, under certain circumstances, could result in mixed stands of AWC.

cedar, harvesting, fire, floristic composition, salvage logging, importance values, vegetation, restoration

• Slides (will open in new window)