Date of Award
Master of Science
Wet pine savannas are among the most diverse ecosystems in North America and provide critical habitat for many species but have seen a dramatic decline in size over the past century due to urbanization, logging, and fire suppression. Coastal pine savannas are also vulnerable to anticipated effects of global climate change. Models of climate change predict rapid sea-level rise along the northern Gulf of Mexico and more intense hurricanes. Restoration of these fragile wetland ecosystems is needed, but the effects of climate change on restored, as well as remnant communities, are unknown. This research aimed to compare resiliency of remnant and restored plant communities to simulated hurricane disturbance. I hypothesized that species composition within both site types will be altered following experimental storm surge, and restored plots will follow a different compositional trajectory due to site conditions including invasion by non-target species and disturbed soils. I compared community composition and soil properties between remnant and restored sites experiencing experimental storm surge. Non-metric multidimensional scaling (NMDS) ordinations and a cluster analysis was used to visualize dissimilarities in composition and permutational analysis of similarity (PERMANOVA) was used to compare composition among treatment, site, and time. Repeated measure analysis of variance (ANOVA) was used to compare soil water conductivity and available ammonium over the course of the study. Results from compositional surveys suggested no significant effect of treatment on community composition, but there were significant vectors for soil moisture and ammonium resulting in different compositional trends and an apparent degree of divergence over time between the two site types. Soil characteristics (texture and bulk density) and pressure from neighboring plants within the restored site are also likely contributing to differences between the two site types. As climate change continues to alter disturbance regimes that shape coastal ecosystems, it will be necessary to assess structure and function of remnant and potentially novel plant communities and their capacity for adaptation.
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