The lightning-sparked Rough Fire burned last year for more than five months, consuming over 150,000 acres of forest in the Sierra Nevada. Now, after a wet winter, the charred forest is slowly coming back to life -- and the first signs of growth are the tiniest of seedlings that may become the world’s largest trees.

In 2015 the Rough Fire in the mountains east of Fresno grew so large that it threatened 12 different giant sequoia groves. Unlike the millions of pine and fir trees that were decimated by the blaze, giant sequoia trees weren’t taken out altogether. Instead, the Rough Fire actually helped them.

"There are a lot of the sequoia groves that burned in the Rough Fire that had never seen fire,” says Tony Caprio, a fire ecologist with Sequoia and Kings Canyon National Parks. "So those trees have been accumulating cones."

As the Rough Fire crept through these groves, Caprio says the fire burned the cones, unleashing oatmeal-like seeds into the fertile soil.

"When you get a pulse of heat up into the crown, it dries those cones and then they will open up and release the seeds. Following the fire in the groves, the ground was littered with just millions and millions of seeds."

Caprio, a few other scientists and I are hiking the 1½-mile North Grove Trail in Grant Grove. Caprio says many giant sequoias withstood the Rough Fire because the Park Service used prescribed burns to decrease the chance of high-intensity blazes. The other reason is the sequoia's fibrous bark.

"It has a lot of air pockets in it," Caprio says. "If you come over here and actually knock on it, it actually sounds hollow. So the heat from the fire doesn’t penetrate the tree."

A little farther down the trail there’s a clear delineation of how prescribed burns can help preserve the landscape. National Park Service Fire Information Officer Mike Theune points to an area west of the trail where everything is charred.

"The fire was so hot," says Theune. "It came up this hill. This is not a place you would want to be. So there was some tree mortality in this inner part."

This area not too far from the famous General Grant Tree was never intentionally burned to reduce the hazards of wildfire.

"You can really see how hot it got in there, up in the canopies, even the giant sequoias,” Theune says. “That’s the heat of the fire. Up to your left you’ll see green. This is an area where the fire literally hit one of our prescribed fire treatments."

When the fire approached this previously treated area the blaze slowed down, preventing damage to the core of Grant Grove. But despite how dead and scorched this area looks today, at our feet are signs of the forest ready to regenerate itself. All those seeds that the fire unlocked are beginning to sprout.

MIKE THEUNE: “They’re really tiny. Almost smaller than your pinky finger.”
EZRA ROMERO: “Do you see one down here?”
THEUNE: “Oh, yeah. I can point them out. They’re little tiny, green... That’s a baby sequoia there. Eventually over 1,000 plus years, one of these baby sequoias will be one of our new giant sequoias."

He also says so many seeds have germinated that clusters of seedlings are growing up together, which he says usually doesn’t happen. By next year Theune and Caprio expect the seedlings to be joined by ferns and other plants.

"It’ll look like there’s a green lawn out there with all the little sequoia seedlings," Caprio says. "The thing we have to think about in the future is how we manage fire in that area, because we want some of those to survive."

He says a prescribed burn a few years ago in another giant sequoia grove taught them how important fire is in thinning out young seedlings.

"Imagine if none of these trees never got thinned out how dense of a forest it would be," Theune says. "So this process takes generations of time. It’s slow, but this is the process of the forest."

They also hope to apply those lessons to this grove, so in 1,000 years these little seedlings could be some of the largest trees in the world.