Abstract Detail

Recent Topics Posters

Oldfield, Callie [1], Evans, Jonathan [2], Reid, Leighton [3].

Ecological resistance to woody species loss in two adjacent southern Appalachian communities.

Ecological resilience and resistance, the ability of a disturbed system to spring back to its original state or to resist change, can be used to assess community stability. Landscape-level resilience may be predicted by factors such as topographic variability, geological heterogeneity, and landscape connectivity. However, not all communities within a landscape may respond to disturbances in the same way, as they may consist of different species assemblages with varying life histories. The southern Cumberland Plateau, thought to be part of a highly resilient landscape, is characterized by two contrasting plant communities. Cove and upland woody plant communities have distinct compositions, which reflect their topographic and edaphic environments as well as differential species responses to disturbance. These disturbances include deer herbivory, windthrow, introduced pathogens, drought, and fire suppression. Differences in composition are maintained despite the opportunity for seed exchange between the adjacent communities. Upland woody species may be more resistant to change due to different life history strategies including sprouting. We hypothesize that over time, the upland forest communities maintain woody plant species representation in all strata as compared to the cove forest, where fewer species are maintained. We measured woody species composition within forest structure classes in permanent plots over 19 years. We found that species richness declined steeply in cove forests, with species losses propagating upwards through size classes. Sapling species richness in the cove declined by 70% (14/20 species) from 1995-2014. Species richness in the upland remained constant. Over time, the 0-2.5 DBH size class lost 15 species in the cove, compared to 4 in the upland forest. We conclude that cove systems are less resistant than upland systems in retaining their local composition and structure, demonstrating that the purported resilience of southern Cumberland Plateau ecosystems is variable between two major community types.

1 - University of the South, Biology, 735 University Ave., Sewanee, TN, 37383, USA
2 - University of the South, 735 University Ave., Sewanee, TN, 37383, USA
3 - Missouri Botanical Garden, Center for Conservation and Sustainable Development, 4344 Shaw Blvd, St. Louis, MO, 63110, USA

Keywords:
ecology
resilience
resistance
forests
disturbance.

Presentation Type: Recent Topics Poster
Session: P, Recent Topics Posters
Location: Exhibit Hall/Savannah International Trade and Convention Center
Date: Monday, August 1st, 2016
Time: 5:30 PM
Number: PRT009
Abstract ID:1177
Candidate for Awards:None