The orange pitch tube and frass at the base indicate red turpentine beetle attacked this fire-damaged tree near Sisters, Oregon. USDA Forest Service photo by Doug Westlind.
In ponderosa pine forests of western North America, wildfires are becoming more frequent and affecting larger areas. Prescribed fire is increasingly used to reduce fuels and mitigate potential wildfire severity. Both fire types damage trees that initially survive their burn injuries but eventually die.
Knobcone pine. Photo courtesy of Matt Reilly.
Vegetation in fire-prone ecosystems evolved to handle frequent fire. Many coniferous species in these environments, for example, have serotinous cones that open when heated to release seeds on bare, fire-cleared soil.
The 2014 Carlton Complex Fire in Washington is one of several past large wildfires being studied to determine how fuel treatment programs and past wildfires affect the spread and severity of wildfires. Photo courtesy of Adam Cohen.
The 2014 Carlton Complex Fire in north-central Washington was a “megafire.” It burned 167,000 acres within 24 hours, driven by strong warm winds through a drought-ridden landscape.
A researcher checks equipment that collected data during a prescribed, stand-replacing fire conducted by the Richfield Ranger District in the Fishlake National Forest, Utah, on June 20, 2019. USDA Forest Service photo by Roger Ottmar.
Weather permitting, the Fire and Smoke Model Evaluation Experiment (FASMEE) is planning another prescribed stand-replacing fire in the Fishlake National Forest, Utah, in early November.
Cheatgrass is an ecosystem transformer.
Photo credit: Becky Kerns
Reintroducing fire is considered critical for the restoration of many fire-dependent forest ecosystems. But, although it can bring many benefits, fire is a disturbance that can also create undesired consequences such as the invasion of noxious weeds.
FASMEE planned operational burn. Photo credit USDA Forest Service.
The Fire and Smoke Model Evaluation Experiment (FASMEE) is a large-scale interagency effort to identify how fuels, fire behavior, fire energy, and meteorology interact to determine the dynamics of smoke plumes, the long-range transport of smoke, and local fire effects such as soil heating and vegetative response.
A plot with heaving logging debris one year after the forest harvest in Matlock, Washington. USDA Forest Service photo by Dave Peter.
Fire Effects Monitor Dustin Smith taking field weather observations. National Interagency Fire Center photo by Kari Greer.
Predicting the weather is notoriously complicated, which can be a challenge for fire managers. Weather plays a major role in how a wildfire behaves and whether it might become erratic or endanger firefighters. For thirty years, fire weather forecasters used the “Haines Index” to assess how weather might intensify wildfire and drive its spread.
A prescribed fire spreading through a mixture of post oak and blackjack oak in north Mississippi (Chickasaw County). Photo by Morgan Varner.
Throughout their range, oak trees have long represented a close relationship between forest and fire. Fire exclusion throws this relationship off balance, and over time open oak woodlands can undergo big changes in composition and structure, sometimes leading to forest plant communities that have never existed before.
Photo courtesy of the National Interagency Fire Center.
Few if any treatments can compete with prescribed fire for its combination of economy and effectiveness in maintaining healthy fire-adapted forests. Prescribed burns are planned meticulously to ensure that they are safe and effective.