Date of Award
Master of Science
Dr. Kevin S. Burgess
Dr. Samantha J Worthy
Dr. Julie Ballenger
Diversity studies via floristic survey and taxonomic metrics have proven essential for discerning community composition and biodiversity, however, phylogenetic analyses are necessary to reveal underlying evolutionary change and potential community assembly patterns. Pitcher plant bogs are highly diverse, highly understudied habitats that contain numerous listed and at-risk plant and animal species of Georgia.
In this study I investigated the taxonomic and phylogenetic diversity of pitcher plant bogs by asking the following questions:
1) What is the taxonomic diversity of pitcher plant bogs,
2) What is the dispersion of phylogenetic diversity within bog habitats, and
3) Does taxonomic and phylogenetic diversity vary among Georgia’s Coastal Plain pitcher plant bogs? Three bogs residing in three different level IV ecoregions (Sea Island Flatwoods, Tifton Uplands, and Atlantic Southern Loam Plains) were chosen for floristic study and tissue samples taken for DNA barcode sequencing. A total of 290 individuals were collected (43 families; 98 genera; and 179 species), of which 254 were sequenced for rbcL and matK gene regions of the chloroplast genome to generate a phylogeny. Sequencing returned 197 successful sequences of both rbcL and matK gene regions, totaling to 207 sequences used to construct a phylogeny after including downloaded GenBank sequences where possible. Species richness, family and genus count, Jaccard Dissimilarity, phylogenetic diversity (PD), mean pairwise distance (MPD), mean nearest taxon distance (MNTD) and standardized effect sizes of MPD and MNTD were calculated for each bog. Jaccard Dissimilarity values show the bogs tend to be different taxonomically, but phylogenetic diversity metrics returned no significant differences between the bogs when looking at PD, MPD, and MNTD. These values suggest random assembly of communities, as well as random phylogenetic structure, showing no evidence of patterns such as clustering or over dispersion.
Little is known about random assembly of plant communities, and study of broader relationships of pitcher plant bogs that includes climate, geology, and soils would be beneficial for greater comprehension of bog plant communities and their conservation.
Flood, Melanie, "Taxonomic and Phylogenetic Diversity of Pitcher Plant Bogs in Georgia's Coastal Plain" (2022). Theses and Dissertations. 461.