What Goes Into a Controlled Burn?

October 19, 2017

The fires now ravaging North California have been particularly bad this year because years of drought have left the area much like a tinderbox.

Without sufficient rain for years, many plants have been left dry or dead, and brief periods of precipitation brought on a boom of growth then dried out again as summer wore on, according to a recent story by The New York Times.

One way to combat this build-up of “fuel load” is a controlled burn.

Stephen Mason, a PhD candidate in environmental science in the College of Arts and Sciences and a graduate research associate at the Academy of Natural Sciences of Drexel University, studies controlled burns and how they affect the environments where they’re performed. He explained how they generally work, what goes into deciding where they happen, and what happens afterward.

What are the benefits of a controlled burn?

Controlled burns are done for a lot of different reasons. One example is to reduce the forest fuel load to minimize the wildfire hazard. Fuel load, essentially, is the accumulation of leaf litter in a forest. Over time, the fuel load will build up, so when a wildfire does happen, the fire will be more intense since there is a lot of “fuel” to burn. So, ironically, to prevent these intense wildfires from happening, trained forest fire professionals will set a controlled fire to purposely reduce the fuel load.

There are also different ecological reasons to do this. One example is that there are a lot of fire-dependent plant species that only will set seed and flower when a fire comes through. These plants have evolved to do this because there will be less competition and soils will be more nutrient-rich after a fire.

Another ecological purpose to do a controlled burn is to create different habitats, such as an open field for different species. Furthermore, that open field could be occupied by a non-native plant species and the best way to exterminate it is to set a controlled fire.

Are controlled burns done everywhere? Are there any spots locally that are good candidates for one?

Controlled burns are done in many places around the world for different reasons. There really isn’t a “best candidate” location for them. It really depends on who owns and/or manages the property and what goals they have.

Locally, Valley Forge National Historic Park is planning to do some controlled burns in the next couple of years for ecological purposes. Also, in the New Jersey Pine Barrens, controlled burns are frequently done to reduce the fuel load since they have historically been susceptible to wildfires due to its unique ecosystem.