Document


Title

Evaluating the ability of the differenced Normalized Burn Ratio (dNBR) to predict ecologically significant burn severity in Alaskan boreal forests
Document Type: Journal Article
Author(s): Karen A. Murphy; Joel Reynolds; John Koltun
Publication Year: 2008

Cataloging Information

Keyword(s):
  • black spruce
  • boreal forests
  • Carex
  • CBI - composite burn index
  • coniferous forests
  • Dendroctonus rufipennis
  • Eriophorum spp.
  • fire case histories
  • fire intensity
  • fire management
  • fire size
  • forest management
  • insects
  • moisture
  • NBR - Normalized Burn Ratio
  • Picea glauca
  • Picea mariana
  • Picea spp.
  • plant diseases
  • remote sensing
  • season of fire
  • sloping terrain
  • soil moisture
  • statistical analysis
  • succession
  • temperature
  • vegetation succession
  • vegetation surveys
  • wildfires
  • wildlife
Region(s):
Record Maintained By:
Record Last Modified: June 1, 2018
FRAMES Record Number: 8661
Tall Timbers Record Number: 22946
TTRS Location Status: In-file
TTRS Call Number: Journals-I
TTRS Abstract Status: Okay, Fair use, Reproduced by permission

This bibliographic record was either created or modified by the Tall Timbers Research Station and Land Conservancy and is provided without charge to promote research and education in Fire Ecology. The E.V. Komarek Fire Ecology Database is the intellectual property of the Tall Timbers Research Station and Land Conservancy.

Description

During the 2004 fire season ~6.6 million acres (~2.7 million ha) burned across Alaska. Nearly 2 million of these were on National Wildlife Refuge System lands inaccessible from the state's limited road system. Many fires burned through September, driven by unusually warm and dry temperatures throughout the summer. Using several fires from this season, we assessed the national burn severity methodology's performance on refuge lands. Six fires, spanning 814 489 acres (329 613 ha), were sampled on five boreal forest refuges. In total, 347 sites were sampled for vegetation composition and ground-based burn severity estimates following the national protocols. The relationship between the differenced Normalized Burn Ratio (dNBR) and composite burn index (CBI) was unexpectedly weak (R2adjusted, 0.11-0.64). The weak relationship was not a result of data or image processing errors, nor of any biotic or abiotic confounding variable. The inconsistent results, and dNBR's limited ability to discern the ecologically significant differences within moderate and high severity burn sites, indicate that the current methodology does not satisfy key Alaskan boreal forest management objectives.

Online Link(s):
Citation:
Murphy, Karen A.; Reynolds, Joel H.; Koltun, John M. 2008. Evaluating the ability of the differenced Normalized Burn Ratio (dNBR) to predict ecologically significant burn severity in Alaskan boreal forests. International Journal of Wildland Fire 17(4):490-499.