PLANT COMMUNITY CHANGE IN THE GULF COASTAL PLAIN DURING THE EARLY PALEOGENE

During the early Paleogene, the Earth experienced a long-term global temperature increase punctuated by multiple hyperthermal events. The warming resulted in a reduction of the latitudinal temperature gradient, in addition to a global increase in seasonality and drought. Changes in faunal and floral distribution and composition have been well documented in the western part of North America and other regions during this time period. Several studies have supported the hypothesis that a widespread band of thermophilic plant communities existed and expanded into the mid latitudes, consistent with biota tracking climate change. It is not clear how well these floras are connected, and how exactly they responded during these rapid and long-term global warming events. My goal is to gain insight in the response of Eocene Gulf Coastal Plain (GCP) plant communities to these warming events using various leaf physiognomic traits (e.g., DILP, leaf mass per area, leaf margin analysis, leaf area analysis, and leaf area index) and systematic census of several floras. For this, I plan to revisit and collect floras from several well-preserved GCP floras from the Claiborne group in Tennessee and Kentucky, that have been used in taxonomic studies but not in paleoecological analyses. Where possible, I will use cuticular analysis to describe leaf morphotypes and narrow down their botanical affinity.