Abstract Detail

Ecology

Kinser, Taliesin [1], Fill, Jennifer [2], Crandall, Raelene [3], Soltis, Douglas [4].

The role of fire and ecological gradients on the phylogeneticcomposition of Coastal Plain pine savannas.

Pine savannas of the North American Coastal Plain are high-diversity ecosystems where highly variable, localized edaphic gradients and fire regimes create heterogeneity in space and time, allowing many rare and dominant species to co-occur across the landscape. Human-mediated landscape change and fire suppression, however, have resulted in loss and disassembly of many of these native communities. Thus, restoration, conservation, and proper management of these dynamic and diverse ecosystems is crucial.
Fire regimes, which vary in seasonality and frequency, are integral to maintaining the high local diversity in pine savannas. Variation in fire regimes affects woody and herbaceous plant cover and composition and is a key focus of management-related research. Summer fires tend to be more intense than those in winter and thus should promote greater herbaceous species dominance, leading to more frequent fires and maintenance of the pine savannas’ open canopy environment. The underlying substrate tends to be sandy and acidic, though the soils grade greatly in texture, moisture, and nutrients. Thus, species sort across the landscape by physiological tolerances of moisture, nutrients, and fire.
Applying phylogenetic trees to management and diversity questions of communities reveals the evolutionary history and relationships among the species within. Thus, such applications can allow for greater insight into both evolutionary and ecological processes that shape community composition. Knowing how different fire regimes affect the evolutionary structure of pine savanna communities along local edaphic gradients can inform management strategies to maximize diversity given the local environment.
Here, we use data from a long-term fire experiment at St. Marks National Wildlife Refuge in Florida to test for relative roles of local edaphic gradients and fire season on shaping community phylogenetic patterns across pine savannas. We collected soil samples from experimental plots, which varied in season of burn, and built phylogenetic trees from groundcover species composition collected across these plots through time. Our results provide insight into how local environmental gradients under different fire regimes structure pine savanna communities and sort evolutionary lineages across those gradients, building the high diversity of these ecosystems.

1 - University Of Florida, Florida Museum Of Natural History, 1659 Museum Road, Dickinson Hall, University Of Florida, Gainesville, FL, 32611, United States
2 - 415 NW 28th Terrace, Gainesville, FL, 32607, United States
3 - University Of Florida, School Of Forest Resources And Conservation, P.O. Box 110410, Gainesville, FL, 32611, United States
4 - University of Florida, Florida Museum of Natural History,, 3215 Hull Road, P. O. Box 2710, Gainesville, FL, 32611, USA

Keywords:
Community Phylogenetics
longleaf pine savannah
fire
Soil
Phylogenetic beta-diversity
management.

Presentation Type: Oral Paper
Number: EC03001
Abstract ID:1024
Candidate for Awards:Ecological Section Best Graduate Student Paper