We show how sedimentary charcoal records from multiple sites within a single landscape can be used to compare fire histories and reveal small scale patterns in fire regimes. Our objective is to develop strategies for classifying and comparing late-Holocene charcoal records in Midwestern oak- and pine-dominated sand plain ecosystems where fire regimes include a mix of surface and crown fires. Using standard techniques for the analysis of charcoal from lake sediments, we compiled 1000- to 4000-yr-long records of charcoal accumulation and charcoal peak frequencies from 10 small lakes across a sand plain in northwestern Wisconsin. We used cluster analysis to identify six types of charcoal signatures that differ in their charcoal influx rates, amount of grass charcoal, and frequency and magnitude of charcoal peaks. The charcoal records demonstrate that while fire histories vary among sites, there are regional patterns in the occurrence of charcoal signature types that are consistent with expected differences in fire regimes based on regional climate and vegetation reconstructions. The fire histories also show periods of regional change in charcoal signatures occurring during times of regional climate changes at ~. 700, 1000, and 3500. cal yr BP.
Bibliographical noteFunding Information:
This project would not have been possible without assistance from undergraduate students Kari Andersen and Crystal Sutheimer (University of Wisconsin) and Andrew Bronson, Leah Dunham, Stesha Dunker, Katie Jensen, Yee Seir Kee, Matt Kinney, Karla Knudson, Paul Kortemeier, Stephen Merten, Stephanie Tomscha, and TJ Webb (Luther College) who collected the charcoal data. Advice from Eric Grimm improved the strategy used for cluster analysis. Michael Twieten and two anonymous reviewers provided helpful comments. We appreciate the generosity of several landowners who granted us permission to collect sediment samples from their lakes. Steve Peterson, Spooner, and Dave Caitheimer were especially helpful in collecting sediment cores. This material is based upon work supported by the National Science Foundation under grant nos. DEB-0320575 to EAL, DEB-0321563 to SH, and DEB-0321589 . Any opinions, findings, and conclusions expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation. Additional funding was provided by a grant from the Center for Global and Regional Environmental Research, University of Iowa , and supplemental funding for undergraduate research from Luther College to EAL, as well as a grant from the University of Wisconsin Graduate School to SCH.
- Charcoal analysis
- Fire history
- Fire regime
- Sand plain