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Blaine Heumann is director of fire management for The Nature Conservancy.

On Aug. 26, a controlled burn (also known as a prescribed fire) got away from a federal fire crew in Yosemite National Park. The Big Meadow fire, which was planned to span one day and 91 acres, is being mopped up today after having spread across more than 7,400 acres of the park. The town of Foresta was evacuated for several days because of the blaze.

Like other escaped fires before it, this incident has raised awareness of a fact that every prescribed fire practitioner knows: No matter how careful you are, no matter how much training your staff have received, any time you light a match, there’s a chance that something will go wrong.

Maybe the wind picks up unexpectedly and the fire jumps the firebreak, contingency plans fail, and a barn, a house or a pine plantation burns. Or maybe some piece of equipment fails and somebody working on the fire gets hurt. Then there’s the smoke to worry about … It’s a fair question: With so much at stake, is it worth it?

First, there’s a lot that can be done to minimize the chance that something will go wrong. And a lot can be done to respond to unexpected events and contain or minimize unfavorable outcomes. In fact, as The Nature Conservancy’s director of fire management, it’s my full-time job to maintain and improve our fire staff’s ability to anticipate and respond to the unexpected. And the Conservancy staff’s record is one that considerably exceeds U.S. averages for both safety and operational cost efficiency. But yes, we are not, nor will we ever be perfect.

Second, the decision to burn or not to burn is made on a place-by-place basis. Some areas are inherently more difficult to burn safely than others, and it’s also true that some landscapes will benefit from fire more than others. We burn where and when our calculus indicates that the benefits to biodiversity far outweigh the costs and potential negative consequences. So it’s a matter of striking the right balance, and I believe that the Conservancy as well as our partners are generally prudent in this regard. But again, as the Big Meadow Fire shows, not perfect.

Most terrestrial ecosystems in North America need fire — to one degree or another — to persist. I’ve never been to Yosemite, but it’s possible, maybe even likely, when all is said and done the Big Meadow fire will have a net positive impact ecologically, and improve habitat for wildlife such as mule deer and cavity-nesting birds.

Perhaps it will reduce fuels in that portion of the park, thereby allowing future managers to let naturally ignited fires take their course. And who knows — maybe the fire will even help some of the affected areas better withstand future climate change impacts.

With 80 percent of U.S. forests and rangelands moderately or severely degraded, and with climate change making the situation worse, something needs to be done. In places where it’s not safe to let naturally ignited wildfires burn, that “something” is often controlled burning.

With more than 30 state-based fire programs that have collectively burned more than a million acres since the 1960’s, the Conservancy is working hard to do its part. (We also get a lot of help on the fireline from federal agencies and other partners.)

In some ways, it’s getting harder for land managers to maintain our current levels of burning, let alone ramp up efforts to make a bigger difference. More and more people are building homes in and around natural areas. While the majority of Americans do understand that fire can play a vital role in nature, people are also quite fearful of fire, especially when someone is planning a controlled blaze close to their neighborhood.

It’s important to realize that prescribed burning can have direct benefits for people as well as nature. For example, many ranchers know that a well-timed fire can improve forage for livestock. And some experts think proactive controlled burning might have prevented the deadly Station fire near Los Angeles.

So fire practitioners must weigh a whole host of potential benefits against the actual and potential costs, and it’s conceivable that we could be taking a risk when we decide not to burn. Clearly this is not easy. But is it worth it? The answer is a qualified yes.

— Text by Blaine Heumann, Cool Green Science Blog
Controlled burns: Are they worth it?
The Nature Conservancy's director of fire management weighs the issue.