Paleobiology Commons^™

Carbon And Nitrogen Isotopic Investigations Of The Late Pleistocene Paleoecology Of Eastern Beringia, Yukon Territory, Using Soils, Plants And Rodent Bones, Farnoush Tahmasebi

Electronic Thesis and Dissertation Repository

During the late Pleistocene (130-12 ka), Beringia, a largely ice-free land located in the Mammoth Steppe Ecosystem, was home to a large grazing community of megafauna. Many of these animals, including the woolly mammoth, became extinct at the terminal Pleistocene. Assessment of the paleoenvironment, nutrient cycling and foraging ecology in Beringia should help to understand the role of climate change in their extirpation. Such information might also help to explain the curiously higher δ¹⁵N of woolly mammoths relative to other coeval herbivores.

This study assessed eastern Beringian paleoecology using stable nitrogen (N) and carbon (C) isotopic analyses of …

Evidence Of Late Quaternary Fires From Charcoal And Siliceous Aggregates In Lake Sediments In The Eastern U.S.A., Joanne P. Ballard

Doctoral Dissertations

The late-glacial transition to the Holocene, 15,000–11,600 cal yr BP, is an enigmatic period of dynamic global changes and a major extinction event in North America. Fire is an agent of disturbance that transforms the environment physically and chemically, and affects plant community composition. To improve understanding of the linkages between fire, vegetation, and climate over the late glacial and Holocene in the eastern U.S., I analyzed lake-sediment cores for charcoal and indicators of wood ash, and compared results to existing pollen records. A new microscopic charcoal record from Anderson Pond, Tennessee revealed high fire activity from 23,000–15,000 cal yr …