CAREER: Environmental Change and Extinction on the Mammoth Steppe

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During the last ice age, large parts of the Arctic were covered in diverse, productive grasslands that supported large populations of mammoths, bison, and other large grazers. This "mammoth steppe" habitat disappeared by 10,000 years ago, along with the megafauna who lived there, but it is still unknown whether their extinction was a cause or an effect of habitat loss. Large herbivores play important roles in maintaining the health of grasslands in modern ecosystems, but the role they played in ice age landscapes is less clear. This project will reconstruct ecological prehistory across Beringia, the ice age land bridge that connected Asia and North America, to establish the timing and nature of extinction, environmental change, and habitat loss. Herbivores remain some of the most threatened animals today, so understanding the "Serengeti of the ice age" can help in the management of Earth's largest animals today, and may provide insights into the role native grazers play in a warming Arctic. This project also will provide education, mentoring, and training for students from middle school to graduate school (including a majority first-generation college student population), who will work collaboratively on this project in the field and in the lab. Project results will be incorporated into a student-designed ice age virtual reality game, and implemented in middle schools by newly trained college student "science ambassadors" to provide cutting-edge science experiences for students in rural, low-income, communities. The research will be conducted in several protected Arctic locations, including Bering Land Bridge National Reserve, Wrangel Island Reserve (a UNESCO World Heritage site and the last known location of woolly mammoths on Earth), and Pleistocene Park, which also will benefit from these results. This project aims to understand the relationship between megaherbivores, vegetation, and environmental change in the mammoth steppe, using new high-resolution, multi-proxy records of megaherbivore collapse, paleovegetation, fire, and climate, from four sites in western and eastern Beringia, including the last dated location of woolly mammoths on Earth. Methods include a mix of traditional (e.g., pollen, charcoal) and emerging (ancient DNA, molecular paleoclimate proxies) approaches that will provide opportunities for interdisciplinary training and education in Quaternary environments. These state-of-the-art paleoenvironmental reconstructions will immerse a cooperative team of graduate, undergraduate, and high school students in field-based, cross-disciplinary cooperative learning and research experiences based around data-informed ice age virtual reality experiences for middle schoolers, with a goal of broadening participation of rural and first-generation college students in STEM. Results will test and refine hypotheses for the ecological context and consequences of megafaunal extinctions, which have implications for interpreting paleorecords and the conservation of modern keystone species in a warming world.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.