Thursday, August 7, 2008

PS 67-144: Use of census data to inform and implement restoration of Gulf dune vegetation

Elise S. Gornish and Thomas E. Miller. Florida State University

Background/Question/Methods

Coastal regions along the Gulf of Mexico provide vital habitat for an array of wildlife, including several threatened and endangered species. The vegetation and geomorphology in coastal areas are interlinked: the landscape determines which plants can become established, while the plants reciprocally act to stabilize sands and sediments. Climate can affect both vegetation and morphology, although the long-term effects of climate are not well understood. Understanding how the vegetation and geomorphology respond to storms and predicted climate change will be necessary to effectively manage coastal areas. This has become particularly evident due to recent storms such as Hurricanes Ivan (2004), Dennis (2005), and Katrina (2005).

We have censused the vegetation on permanent plots on St. George Island in N. Florida annually since 1999. Vegetation patterns across sites and years has been analyzed using detrended correspondence analysis (DCA). Correlations between vegetation change and climate for the last 8 years demonstrate that the vegetation of island habitats is affected by a variety of climate events. Vegetation on foredunes is most affected by tidal surge and flooding associated with major storms, while interdune areas are most affected by both surge and spring temperatures and backdune areas by spring drought. The census was used to identify six plant species that are either resistant to storm effects or respond positively following storms: Centella asiatica, Fimbristylis spp., Muhlenbergia capillaris, Schizachyrium littorale, Sporobolus virginicus and Uniola paniculata. Individuals of these six species have been transplanted into fore-, inter-, and backdune habitats and are being monitored bi-monthly for survival and growth. These transplant experiments will test the prediction that these species may be useful for restoring damaged coastal areas.

Results/Conclusions

Results of this work will help local, regional and national reserve managers to implement efficient and cost-effective methods of management and restoration to ameliorate the effects of climate change on dune habitats.


In the future, we are interested in determining whether the predictions of vegetation change on St. George Island can be extrapolated over a wider scale using ground-based spectral data along with satellite and aerial imagery. As a first step, we are comparing the known vegetation changes on St. George Island with vegetation on nearby Cape George Island to determine the extent to which vegetation patterns can be extrapolated to nearby areas using remote sensing technology.