Chapman, Julia , McEwan, Ryan .
Tree regeneration ecology of an
old-growth central Appalachian forest: Diversity, temporal dynamics, and
Diversity and compositional dynamics in deciduous forests of eastern North America are increasingly subject to an array of drivers including natural small- and large-scale disturbances, invasion by exotic species, pathogens, insect pests, and anthropogenic influences. In order to understand reactions to these drivers, there is a pressing need to understand baseline dynamics in these forests. In particular, these forests are thought to be undergoing a long-term dominance shift in which maples (Acer spp.) are replacing oaks (Quercus spp.). We examined dynamics of woody understory species in an old-growth central Appalachian forest to 1) document baseline dynamics over a decade and 2) investigate the reaction of the seedling and shrub-layer vegetation to a recent fire in one portion of the study site. We were also interested in understanding in how species diversity in the woody understory reacted to gradients of productivity and to the recent fire. Over a ten-year interval (2000 - 2010), Acer spp. sapling densities decreased significantly (P < 0.01) and Quercus spp. sapling densities did not change significantly. Seedling densities of Acer spp. increased significantly (P < 0.01) while mean cover decreased significantly (P < 0.01). For a few Quercus species, seedling densities increased significantly (P < 0.01), and mean cover of Quercus alba seedlings increased significantly (P < 0.05). Significant unimodal relationships (P < 0.01) were exhibited between diversity and productivity in both understory strata. Plots burned by fire had significantly lower sapling layer density and species richness (P < 0.001) in 2010 compared to pre-disturbance data in 2000. In the same area, the seedling layer did not show a clear response to this fire disturbance. Further work is needed to understand how various ecosystem drivers are influencing the composition of forest regeneration layers and how those trends relate to overstory succession. The factors that constrain or promote diversity to create a unimodal relationship with productivity also need to be examined.
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1 - University Of Dayton, Biology, 300 College Park, Dayton, OH, 45469-2320, USA
Presentation Type: Poster:Posters for Sections
Location: Khorassan Ballroom/Chase Park Plaza
Date: Monday, July 11th, 2011
Time: 5:30 PM