Authors: Benjamin Nauman*, UCLA, Glen MacDonald, UCLA, Matthew Kirby, California State University, Fullerton
Topics: Paleoenvironmental Change, Physical Geography, Biogeography
Keywords: paleofire, biogeography, environmental change, Holocene, California, fire
Session Type: Paper
Start / End Time: 11:10 AM / 12:25 PM
Room: Grand Ballroom 1, Sheraton, IM Pei Tower, Second Floor Level
Presentation File: No File Uploaded
Over the course of the past few decades, California has experienced an increase in the intensity and size of wildfires, associated with affects stemming from Anthropogenic Climate Change. Analysis of macroscopic charcoal from lake sediments was used to determine if similar increases in burning occurred during previous warm periods, such as the Medieval Climate Anomaly, and the Holocene Climatic Optimum.
A database of 20 existing macroscopic charcoal sites was compiled for California, with sites located primarily in far-Northern California, and the Sierra Nevada mountain range, as well as in the San Bernardino Mountains of Southern California. From the data we have collected, we do not see a trend towards increased fire activity during prior warm periods, though there are some similarities with the records from certain regions. Charcoal records from Northern California generally have rising rates of charcoal accumulation from the beginning of the Holocene to the modern period. In addition, several sites in the Sierra Nevada region have significant rises in charcoal influx starting at around 3000 y.b.p.
The lack of a common signal with many of these charcoal records could be associated with several factors. One factor could be a shift to novel fire regime when compared to those in previous periods of extended drought and warm temperatures. It also may reflect local differences in basin size, slope, and vegetation, which can influence charcoal influx and obscure larger fire trends. Future work will aim to refine analyses of California’s prehistorical fire activity.