Factors associated with the severity of interacting fires in Yosemite National Park

Fire Ecology
By: , and 



In 1972, Yosemite National Park established a wilderness fire zone in which lightning fires were allowed to run their courses under prescribed conditions. This zone was expanded in 1973 to include the 16 209 ha Illilouette Creek basin, just to the southeast of Yosemite Valley. From 1973 through 2011, there have been 157 fires in the basin. Fire severity data were collected on all 28 of those fires that were larger than 40 ha. The proportion burned in each fire severity class was not significantly associated with fire return interval departure class. When areas were reburned, the proportion of unchanged severity fire decreased while the proportion of high severity fire increased. The proportion of fire severity of the subsequent fires was associated with the number of years since last burned, the burning index, and the severity of the previous fires. The main effects were significant for unchanged severity and low severity, and the interaction between return interval class and burning index class was significant for high severity. Most vegetation types remained the same when burned with unchanged, low, or moderate severity, while high severity often resulted in conversion to montane chaparral. The factors that were associated with reburn severity worked in combination with each factor influencing some aspect of severity. Managers and scientists can use this information to better understand the role fire plays in these ecosystems and how to best manage this dynamic ecological process.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Factors associated with the severity of interacting fires in Yosemite National Park
Series title Fire Ecology
DOI 10.4996/fireecology.0801011
Volume 8
Issue 1
Year Published 2012
Language English
Publisher Association for Fire Ecology
Contributing office(s) Western Ecological Research Center
Description 21 p.
First page 11
Last page 31
Country United States
State California
Other Geospatial Illilouette Creek
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