Next Article in Journal
Assessing the Influence of Roads on Fire Ignition: Does Land Cover Matter?
Previous Article in Journal
Fire Severity and Vegetation Recovery on Mine Site Rehabilitation Using WorldView-3 Imagery
Open AccessArticle

Historical Fire Regimes in Ponderosa Pine and Mixed-Conifer Landscapes of the San Juan Mountains, Colorado, USA, from Multiple Sources

Program in Ecology/Department of Geography, University of Wyoming, Laramie, WY 82071, USA
Received: 28 May 2018 / Revised: 4 July 2018 / Accepted: 7 July 2018 / Published: 9 July 2018
Reconstructing historical fire regimes is difficult at the landscape scale, but essential to determine whether modern fires are unnaturally severe. I synthesized evidence across 725,000 ha of montane forests in the San Juan Mountains, Colorado, from forest atlases, forest-reserve reports, fire-scar studies, early reports, and newspaper accounts. Atlases mapped moderate- to high-severity fires during 1850–1909 (~60 years), and 86% of atlas area was attributable to 24 fire years. Historical fire rotations from atlases were mostly 225–360 years for high-severity fires and 133–185 years for moderate- to high-severity fires. Historical low-severity fire from tree-ring data at 33 sites revealed a median fire rotation of 31 years in ponderosa pine, 78 years in dry mixed-conifer, and 113 years in moist mixed-conifer forests. Only 15% of montane sites had “frequent-fire” forests with fire rotations <25 years that kept understory fuels at low levels. Moderate- to high-severity fire rotations were long enough to enable old-growth forests, but short enough to foster heterogeneous landscapes with expanses of recovering forests and openings. About 38–39% is still recovering from the 1850–1909 fires. Large, infrequent severe fires historically enhanced resilience to subsequent beetle outbreaks, droughts, and fires, but have burned at lower rates in the last few decades. View Full-Text
Keywords: wildfires; megafires; high-severity fires; frequent fire; historical fires; fire regimes; forest atlases; San Juan Mountains; Colorado; USA wildfires; megafires; high-severity fires; frequent fire; historical fires; fire regimes; forest atlases; San Juan Mountains; Colorado; USA
Show Figures

Figure 1

MDPI and ACS Style

Baker, W.L. Historical Fire Regimes in Ponderosa Pine and Mixed-Conifer Landscapes of the San Juan Mountains, Colorado, USA, from Multiple Sources. Fire 2018, 1, 23. https://doi.org/10.3390/fire1020023

AMA Style

Baker WL. Historical Fire Regimes in Ponderosa Pine and Mixed-Conifer Landscapes of the San Juan Mountains, Colorado, USA, from Multiple Sources. Fire. 2018; 1(2):23. https://doi.org/10.3390/fire1020023

Chicago/Turabian Style

Baker, William L. 2018. "Historical Fire Regimes in Ponderosa Pine and Mixed-Conifer Landscapes of the San Juan Mountains, Colorado, USA, from Multiple Sources" Fire 1, no. 2: 23. https://doi.org/10.3390/fire1020023

Find Other Styles
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop