Fire cycles in North American interior grasslands and their relation to prairie drought

K. J. Brown, J. S. Clark, E. C. Grimm, J. J. Donovan, P. G. Mueller, B. C.S. Hansen, I. Stefanova

Research output: Contribution to journalArticlepeer-review

83 Scopus citations

Abstract

High-resolution analyses of a late Holocene core from Kettle Lake in North Dakota reveal coeval fluctuations in loss-on-ignition carbonate content, percentage of grass pollen, and charcoal flux. These oscillations are indicative of climate-fuel-fire cycles that have prevailed on the Northern Great Plains (NGP) for most of the late Holocene. High charcoal flux occurred during past moist intervals when grass cover was extensive and fuel loads were high, whereas reduced charcoal flux characterized the intervening droughts when grass cover, and hence fuel loads, decreased, illustrating that fire is not a universal feature of the NGP through time but oscillates with climate. Spectral and wavelet analyses reveal that the cycles have a periodicity of ≈160 yr, although secular trends in the cycles are difficult to identify for the entire Holocene because the periodicity in the early Holocene ranged between 80 and 160 yr. Although the cycles are evident for most of the last 4,500 yr, their occasional muting adds further to the overall climatic complexity of the plains. These findings clearly show that the continental interior of North America has experienced short-term climatic cycles accompanied by a marked landscape response for several millennia, regularly alternating between dual landscape modes. The documentation of cycles of similar duration at other sites in the NGP, western North America, and Greenland suggests some degree of regional coherence to climatic forcing. Accordingly, the effects of global warming from increasing greenhouse gases will be superimposed on this natural variability of drought.

Original languageEnglish (US)
Pages (from-to)8865-8870
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Volume102
Issue number25
DOIs
StatePublished - Jun 21 2005

Keywords

  • Aridity cycles
  • Charcoal
  • Holocene
  • Northern Great Plains
  • Pollen

Fingerprint Dive into the research topics of 'Fire cycles in North American interior grasslands and their relation to prairie drought'. Together they form a unique fingerprint.

Cite this