Document Type



Doctor of Philosophy (PhD)



First Advisor's Name

DeEtta Mills, PhD

First Advisor's Committee Title

Committee Chair

Second Advisor's Name

John Kominoski, PhD

Second Advisor's Committee Title

Committee Member

Third Advisor's Name

Jessica Liberles, PhD

Third Advisor's Committee Title

Committee Member

Fourth Advisor's Name

Bruce McCord, PhD

Fourth Advisor's Committee Title

Committee Member

Fifth Advisor's Name

Jeffrey Wells, PhD

Fifth Advisor's Committee Title

Committee Member


Microbiome, Soil microbial communities, Microbial Functional Genes, Biogeochemical Cycling, Saltwater Intrusion, Everglades, Forensics

Date of Defense



Coastal wetlands, such as the Everglades, are increasingly being exposed to stressors that have the potential to modify their existing ecological processes because of global climate change. Their soil microbiomes include a population of organisms that are important for biogeochemical cycling, but continual stresses can disturb the community's composition, causing functional changes. The Everglades features wetlands with varied salinity levels, implying that they contain microbial communities with a variety of salt tolerances and microbial functions. Therefore, it's critical to track the effects of stresses on these populations in both freshwater and brackish marshes. The study addressed this by first constructing a baseline microbial community, then analyzing taxonomic alterations that happened after a long-term disturbance like seawater intrusion, and then determining the soil characteristics that most contributed to the difference in soil communities.

To estimate the microbiome’s diversity, two standard genetic study approaches were compared in Chapter 2. Length Heterogeneity-PCR (LH-PCR) was used to detect the initial diversity, and Next Generation Sequencing (NGS) was used to detect the taxonomic diversity. The Archaea and bacteria populations were examined. With both techniques, it was determined that each location had a distinct bacterial and Archaeal community distribution. Changes in relative abundance of taxonomies before and after experimental saline treatment revealed that various taxa react to stresses in different ways, providing insight into how communities are responding.

By analyzing taxonomic alterations, Chapter 3 defined the microbial communities participating in important biogeochemical cycles and evaluated how their functional potential altered following long-term salt inputs. The nitrogen, carbon, sulfur, and phosphorus cycles were studied by sequencing a microbial functional gene involved in each of these processes. The relationships between the observed soil physiochemical properties and microbial composition before and after saline treatment were investigated in Chapter 4. Once saline was introduced, changes in the properties responsible for alterations in community variation were observed. The microbiome's value for ecological and forensic purposes was also investigated, specifying its enormous potential. These findings add to the understanding of microbiomes by demonstrating how changes in soil qualities impact communities both before and after a disturbance such as saltwater intrusion.




Included in

Biology Commons



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