[fire crackling] In the North Carolina sandhills, they'll set the forest ablaze for its own good.

- Well, thanks again for coming out.

So today we're going to be burning Unit 3 here at Callaway Forest Preserve.

- Forests like longleaf pine need fire to stay healthy.

It clears brush and invasive plants and opens it up for those who depend on it.

- Winds will be southwest at 5 to 10 miles an hour.

- Alan Teed is burn boss for the Nature Conservancy.

Before anyone lights anything, there's a briefing.

And the first item on the agenda isn't fire.

- Since our number one priority today is firefighter and public safety, we're going to cover safety and medical first.

- Teed tried to run this burn twice before.

Both times he canceled.

- That's engine 602.

There's trauma kits in there.

- In Hoke County, the stakes for getting it right have gotten more complicated, like new housing development.

- We have other smoke sensitive areas in our general vicinity, such as hospitals, schools.

I feel like I've prioritized wind direction a lot more because we want to steer our smoke away from these smoke sensitive areas and be good neighbors.

[laughing] - Today the winds cooperated.

Crew of about 20, 75 acres and something called a prescribed burn.

- A prescribed burn is the intentional use of fire on the landscape as a restoration tool.

In our case, we're using it to restore the longleaf pine ecosystem of North Carolina.

I bring JD in closer and then stagger Matt and let your baseline and JD's come together before Matt lights a chain off.

- [on radio] OK copy that.. - The longleaf pine once covered about 92 million acres from Virginia to East Texas.

Today, less than 4% remains.

For most of the 20th century, the official position on the fire was simple.

Put it out.

It was the wrong call.

- Healthy forests don't exist without precipitation, without rain.

Longleaf doesn't exist without fire.

It is a fully fire driven, fire adapted ecosystem.

By burning, you're opening things up.

You're putting a little bit of nutrients into the ground, which is really important here in the sand hills where it's deep, sandy, low nutrient soils.

- Break that cycle long enough and other species move in.

Fast growing, aggressive, hungry for the same resources the longleaf needs.

- What is that you just held?

- Uh... It appears to be a turkey oak.

- And you don't want those here?

- Nope, because they grow fast and they can outcompete longleaf pine for resources like sunlight and water.

- As crews work the perimeter, Teed is building a buffer of already burned black ground.

A catcher's mitt, they call it, that clears the way for the next phase of the operation.

A drone to help attack the brush from the other side.

- So we fly drones on control burns for a number of reasons.

One reason is the drones allow us to do interior ignitions inside the unit without putting firefighters inside.

- What the drone carries isn't water, but a weapon from the rear.

- So we're doing a bench test with our igneous system, which means we're going to inject two of our ignition spheres with glycol while it's on the ground and we'll be able to watch the chemical reaction and how long it takes so that we know what it's going to do when we're flying over the unit.

They're going to drop out of the hopper of igneous.

I'm going to grab them and I'm going to put them over here and we're going to count to determine how long it takes for the chemical reaction to occur before ignition.

- Okay, go ahead.

- All right, drop two.

[blowing, gurgling sounds] [pop] [fizzle sound] Thirty-two seconds.

- Today's crew came from agencies across the region.

Ask them why, and the answers sound a lot alike.

- Fire is one tool out of many land management tools that is super cost effective.

We're just keeping this natural fire cycle in place.

- Restore the forest and the rest follows.

The red-cockaded woodpecker, once endangered, now recovering, nests only in living longleaf.

So does the Bachman sparrow.

So does the Pine Barrens tree frog.

Their futures are tied to this work, acre by acre, burn by burn.

- And that's going to be here in places we've preserved for next generations.

- Just seeing the stages of restoration that we put the ecosystem through and then seeing it thrive is just incredibly rewarding.

- Turn it on.

- How is it?

- Is it in?

- No.

How is it?