Richards, J.H. , Philippi, T.E. , Kalla, P. , Scheidt, D. .
Defining subtropical marsh plant communities: Characterization of Everglades marsh vegetation using a landscape-scale random sample.
Marsh vegetation is often sampled in localized areas and/or for specific investigative needs that bias understanding of landscape patterns. In order to understand community composition at a landscape scale, we randomly sampled southern Florida marshes with an equal probability GRTS (generalized random tessellation stratified) design as part of the 2005 US EPA Region 4 REMAP project. We sampled 230 sites for species presence in 20 ¬ľ-m2 quadrats within 20-m2 plots. The plot data were used to identify plant associations using hierarchical clustering and non-metric multidimensional scaling (NMS). Our analyses showed five clusters of species. The most species-rich group was defined by wet prairie species such as Muhlenbergia capillaris (muhly) and Panicum tenerum. This group had 41 species with significant indicator values (p < 0.05). Sawgrass, Cladium jamaicense, was present at 100% of the sites in this group, but because of high sawgrass frequency and abundance throughout the landscape, the other species shared among these sites defined this group. The largest group in the analysis was defined by sawgrass. The next largest group was relatively biodiverse; the spikerush Eleocharis cellulosa had the highest indicator value in this group. The fourth group was associated with deeper water; white water lily, Nymphaea odorata, was the most common species. The fifth group was defined by cattail (Typha domingensis), had 7 outlier sites, and was associated with high soil phosphorus concentrations. Removal of outlier sites changed this groupís species composition and removed the association with high soil phosphorus but kept the distinctness of the group in the analysis. In the NMS ordination the sawgrass, spikerush and water lily groups overlapped but occupied different sectors of ordination space. Community distributions varied across the landscape; the muhly community was restricted to the southern part of the ecosystem, while the water lily community was less abundant there.
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1 - Florida International University, Dept. of Biological Sciences, 11200 SW 8th St., Miami, FL, 33199, USA
2 - National Park Service, Natural Resource Program Center, Office of Inventory, Monitoring, and Evaluation, 1201 Oakridge Drive, Suite 150, Fort Collins, CO, 30605, USA
3 - U.S. Environmental Protection Agency, Region 4, Science and Ecosystem Support Division, Athens, GA, 30605, USA
4 - U.S. Environmental Protection Agency, Region 4, Water Protection Division, Athens, GA, 30605, USA
Presentation Type: Oral Paper:Papers for BSA Sections
Location: Wasatch B/Cliff Lodge - Level C
Date: Monday, July 27th, 2009
Time: 10:30 AM