Cooperating Agencies:

• White Mountain Apache Tribe
• Apache-Sitgreaves National Forests

Location:

97 sites across the nearly 470,000 acre Rodeo-Chediski fire area in both the White Mountain Apache Reservation and the Sitgreaves National Forest.

Date Initiated:

2003

Description:

In the summer of 2002, the largest wildfire in Arizona’s history burned across a large portion of the White Mountain Apache Reservation and the Sitgreaves National Forest near the towns of Show Low and Heber. Dubbed the Rodeo-Chediski fire after two individual blazes combined into one monster burn, the fire covered nearly 468,000 acres by the time it was extinguished with the onset of monsoon rains in early July. While the fire was devastating in its overall scope, the severity was not uniform across the burn area. Instead the fire left a mosaic of burn severities (seen in the map above, from satellite imagery, and the photos below) from high-intensity blowouts in which entire landscapes were reduced to ash and charred tree trunks, to low-intensity zones where the fire burned on the surface and left most of the trees alive. While there are multiple reasons for this heterogeneity in burn severity, a major factor was pre-fire forest management, including varying degrees of logging, fuels treatments and prescribed burning.

To investigate the effects of pre-fire treatments on the forest structure and understory vegetation communities after the fire burned through, researchers from the ERI established a study in 2003 on nearly 100 sites in which the fire burned in ponderosa pine forest (primarily in the northern, higher-elevation part of the fire on both the White Mountain Apache reservation and the Sitgreaves National Forest). Stratifying the sites based on fire severity and pre-fire treatments, graduate students Barb Strom and Amanda Kuenzi studied the fire’s effects on tree structure and understory vegetation, respectively.

Strom’s study indicated that pre-fire forest management activities did affect the severity of the burn across the landscape. She found that treatments within the decade before the fire (particularly the combination of cutting and prescribed burning, as opposed to either treatment individually) were associated with more live trees remaining after the fire, less intense fire behavior, as indicated by bole char and needle scorch height, and a greater amount of pine regeneration. Kuenzi found that areas which burned at higher severity had significantly more vegetative cover, but she did not detect a difference due to pre-fire treatments. Interestingly, she also found a relatively small response of exotic species to the fire, which contrasts sharply with the effects of many other fires across the Southwest in areas with a history of active management.

Project Status:

Measurements and analysis for the Rodeo-Chediski projects are completed, and there are no plans at present to return to the site.

Publications:

• Kuenzi, A.M. 2006. Pre-fire Treatment Effects and Understory Plant Community Response on the Rodeo-chediski Fire, Arizona. Unpublished master’s thesis. Northern Arizona University, Flagstaff, AZ.
• Kuenzi, A.M., P.Z. Fulé, and C.H. Sieg. 2008. Effects of fire severity and pre-fire stand treatment on plant community recovery after a large wildfire. Forest Ecology and Management 255:855-865.
• Strom, B.A. 2005. Pre-fire treatment effects and post-fire forest dynamics on the Rodeo-Chediski burn area, Arizona. Unpublished master’s Thesis. Northern Arizona University, Flagstaff, AZ.
• Strom, B.A., and P.Z. Fulé. 2007. Pre-wildfire fuel treatments affect long-term ponderosa pine forest dynamics. International Journal of Wildland Fire 16:128-138.