Plantations. Burn. Hotter.
The evidence is there. When a forest is clearcut and replanted, a timber plantation of dense, young trees takes hold. The consequences for the landscape are hotter, stand-replacing fires that provide a source of hot embers to spread wildfires.
Wildfire is a natural part of the landscape in many parts of the world. Fires burned with mixed severities for tens of thousands of years in forests in the Western US. As the climate changes, wildfires have become a growing concern for communities near fire prone landscapes. Scientists are studying how land management influences fire behavior.
The Big Burn and the Consequences of Disaster Policy
How did we get here? Watch the TedTalk by Paul Hessburg for a look at the history and policy surrounding fire and forests in the West.
Forests of Fire
In the Western US, land ownership, fuels, slopes, and weather all contribute to the degree to which fires burn on the landscape. It is difficult to determine which factors contributed to fire severity in a given place. But several studies show that tree plantations burn hotter than native forests. For example, a recent (2018) study from Oregon State University shows that in the 2013 Douglas Complex Fire, industrial plantation forest burned with greater severity than publicly owned forests. The industrial forests were stocked with young, closely planted trees while the public land had a mixed conifer forest with many older trees. Weather was the main driver in forest fire activity, but after controlling for weather researchers were able to determine that plantations burned with greater severity. Given that weather is impossible to control (aside from taking action to reduce climate change emissions), forest managers are looking to how vegetation contributes to the spread and intensity of forest fires.
Climate Change and Forest Fires
Southwest Oregon and northwest California is an environment where mixed-severity fire is a historical reality. As the area moves toward a hotter and drier climate, we must use the evidence that densely planted and heavily managed forest stands will increase uncharacteristically severe fire. The Douglas Complex Fire study adds to the growing body of research to show that tree plantations burn hot. A 2004 study in the Klamath Mountains and a 2009 study after the Biscuit fire found similar results.