PLANT COMMUNITY CHANGE ACROSS THE PALEOCENE-EOCENE BOUNDARY IN THE GULF COASTAL PLAIN, CENTRAL TEXAS

During the early Paleogene the Earth experienced long-term global warming punctuated by several short-term ‘hyperthermal’ events. Fossil studies suggest tropical climates expanded into extra-tropical areas, creating a widespread band of thermophilic floras that expanded into the mid-latitudes. Many Paleocene Eocene Boundary (PEB) floras have been described in western North America, but relatively little is known about the paratropical floras which would have extended across the Gulf Coastal Plain (GCP). This study assesses the preserved floras from the GCP in Central Texas before and after the Paleocene Eocene Boundary (PEB) to define plant ecosystem changes associated with rapid global warming in this region. These floras suggest a high turnover rate, change in plant community composition, and uniform plant communities across the GCP at the PEB. Paleoecology and paleoclimate estimate from Central Texas floras suggest a warm and wet environment, indicative of tropical seasonal forest to tropical rainforest biomes. Fossil evidence from the GCP combined with data from the NGP and modern tropics suggest that warming during the early Paleogene helped create a paratropical belt that extended into the mid-latitudes. Evaluating the response of plant communities to rapid global warming is important for understanding and preparing for current and future global warming and climate change.