MAMMOTH BURPS: DID HUMAN IMPACTS ON THE ENVIRONMENT PREDATE THE HOLOCENE?
SMITH, Felisa, Biology, University of New Mexico, MSC 03-2020, 1 University of New Mexico, Albuquerque, NM 87131, fasmith@unm.edu, ELLIOTT, Scott M., Climate, Ocean, Sea Ice Modeling Team, Los Alamos National Laboratory, Los Alamos, NM 87545, and LYONS, S. Kathleen, Department of Paleobiology, National Museum of Natural History, Smithsonian Institution, P.O. Box 37012, Washington, DC 20013 The human-mediated extinction of large herbivorous megafauna in the late Pleistocene had profound effects on terrestrial community structure and function, but may also have influenced atmospheric gas exchange. Herbivorous mammals are major producers of methane, a potent greenhouse gas with a high global warming potential; domestic livestock currently contribute ~20% of the annual input. Here, using allometric relationships between body mass and density, methane production and estimates of geographic range, we calculate the annual decrease in methane production resulting from the extinction of 114 spe
