Century-scale fire dynamics in a savanna ecosystem

Bérangère A. Leys, Daniel Griffin, Evan R. Larson, Kendra K. McLauchlan

Research output: Contribution to journalArticlepeer-review

4 Scopus citations

Abstract

(1) Background: Frequent fire, climate variability, and human activities collectively influence savanna ecosystems. The relative role of these three factors likely varies on interannual, decadal, and centennial timescales. Here, we tested if Euro-American activities uncoupled drought and fire frequencies relative to previous centuries in a temperate savanna site. (2) Methods: We combined records of fire frequency from tree ring fire scars and sediment charcoal abundance, and a record of fuel type based on charcoal particle morphometry to reconstruct centennial scale shifts in fire frequency and fuel sources in a savanna ecosystem. We also tested the climate influence on fire occurrence with an independently derived tree-ring reconstruction of drought. We contextualized these data with historical records of human activity. (3) Results: Tree fire scars revealed eight fire events from 1822–1924 CE, followed by localized suppression. Charcoal signals highlight 13 fire episodes from 1696–2001. Fire–climate coupling was not clearly evident both before and after Euro American settlement The dominant fuel source shifted from herbaceous to woody fuel during the early-mid 20th century. (4) Conclusions: Euro-American settlement and landscape fragmentation disrupted the pre-settlement fire regime (fire frequency and fuel sources). Our results highlight the potential for improved insight by synthesizing interpretation of multiple paleofire proxies, especially in fire regimes with mixed fuel sources.

Original languageEnglish (US)
Article number51
Pages (from-to)1-15
Number of pages15
JournalFire
Volume2
Issue number3
DOIs
StatePublished - Sep 2019

Bibliographical note

Funding Information:
This research was funded by NSF-DEB-1145815 to K.K.M., NSF-DEB-1655148 to K.K.M. and NSF-DEB-1655144 to D.G. We thank Cedar Creek Ecosystem Science Reserve for permission to conduct field work. Dan Engstrom directed the collection of the short sediment core and provided the 210Pb analysis. Members of the Novus III workshop assisted with sample collection. Jakob Hanschu provided charcoal data. Margaret Bialecki assisted in preparation, dating, and analysis of wood samples. We are grateful to the editor, and several anonymous reviewers whose suggestions led to an improved manuscript.

Publisher Copyright:
© 2019 by the authors. Licensee MDPI, Basel, Switzerland.

Keywords

  • Euro-American settlement
  • Fire intensity
  • Fire regime
  • Fire scar
  • Multi-proxy
  • Savanna
  • Sedimentary charcoal

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