A $231,571 National Science Foundation grant was awarded to Robert Gastaldo, the Whipple-Coddington Professor of Geology, and Ian Glasspool, research scientist in geology, for their project titled “RUI: The Timing and Evolution of Devonian Fire Systems and Their Implications for Atmospheric Oxygen Concentration.” This marks the 10th NSF grant Gastaldo has received since he began at the College in 1999 and the first for Glasspool.
In explaining the project, Gastaldo said that the consequences of colonization of the land’s surface by plants dramatically, and irreversibly, changed the course of Earth history. Plants photosynthesize; they draw carbon dioxide into their cells, metabolically create carbon-based chemicals, and expel oxygen. As land plants spread across the continents during the Devonian Period (419-359 million years ago), the concentration of oxygen in the atmosphere also increased, altering geochemical and biological processes. The timing and extent of oxygen increase can be tied directly to the burning of the landscape, as wildfire (ignition of dry plant biomass) began when oxygen levels reached a minimum of ~15 percent of the atmospheric gas concentration. Wildfires in which plant material is not completely combusted result in charcoal, and fossil charcoal can provide scientists with not only evidence of wildfire but also to the temperature at which the material burnt.
The NSF-funded project is designed to evaluate the complementary roles of oxygenation and wildfire frequency in the Devonian during the interval when land plants evolved from low-lying groundcover and emergent herbs to woody trees and forests. The three-year project will examine fossil plant localities along the eastern seaboard, from Virginia to Québec, Canada, and engage Colby students in both field and laboratory studies.