Understanding the coupled response of vegetation and fire to climatic variation since the Last Glacial Maximum

Marlon Jennifer R, New Haven CT

Investigators

Abstract

Dr. Jennifer Marlon is awarded an NSF Earth Sciences Postdoctoral Fellowship to carry out a research and education plan at the University of Wisconsin - Madison. Dr. Marlon will use paleoenvironmental data and a dynamic global vegetation-fire model to study past climate change impacts on fire-vegetation interactions. She will first conduct meta-analyses of charcoal and pollen data from lake sediments to reconstruct centennial- to millennial-scale patterns of fire and vegetation change at regional to continental scales. A cutting-edge, fire-enabled dynamic global vegetation model will then be used to simulate paleofire activity under climate conditions very different from today (i.e., 6000 and 21,000 years ago). Results from the charcoal and pollen analyses will be used to assess model performance through data-model comparisons. Finally, results from the synthesis and data-model comparison will be used to design and implement sensitivity experiments with the coupled vegetation-fire model. The aim of the experiments will be to advance our understanding of how climate and vegetation control fire regimes, and of the range of responses in vegetation and fire to potential future climate changes. The likely impacts of global warming on vegetation and wildfires at broad spatial scales are largely unknown. Yet, we know that projected climate changes will have major consequences for ecosystem dynamics, including disturbance regimes, and that feedbacks from changing fire regimes in particular will affect global biogeochemical cycles, as well as atmospheric chemistry and physics. Such consequences, in turn, threaten ecosystem services, such as the provisioning of clean air and water, and thus human health and livelihoods. Paleofire records indicate that fire regimes are highly sensitive to climate changes, particularly when the changes are abrupt, and regardless of the direction of change. This research will improve our understanding of natural variability in fire regimes and thus improve our ability to model future changes in fire. Results will also provide ecologists and natural resource managers with critical context for current fire-regime changes in North America. Outreach and education activities associated with this research include the development of standardized and integrated datasets of past fire and vegetation changes that will be made available to the broader community on a public website. Dr. Marlon will also develop course material on fire, paleoecology and paleoclimatology for undergraduates and graduates at the host institution.