[bird cawing] This is what devastation looks like.

[bird cawing] This is what happens when 30 inches of rain over three days, combined with 100 mile per hour winds, slam into western North Carolina mountains.

[bird cawing] Hurricane Helene was like a giant monster, crashing through the forest, bringing down 100,000 acres of trees.

80-foot oaks and maples were splintered, root systems torn away, landslides scraped away entire sides of mountain.

[bird cawing] Scientists say the forest structure of the Blue Ridge Mountains suffered damage never before recorded, leaving one of America's most diverse ecosystems hanging in the balance.

[music] This is the Elk Mountain area just north of Asheville.

What you see here is just a small part of what went down September 27th when Hurricane Helene came through.

Trees are down everywhere.

In fact, 17% of the trees in Buncombe County were lost during the storm.

What we should be seeing right behind me is green, not sky or barren bark.

And infrastructure was hit hard too, roads, bridges, power.

But what about the infrastructure of the forest?

There are experts on the mountain right now trying to find out just what went down.

It's all about what's called the tree canopy and keeping our forest ecosystem healthy.

So I've always loved plants.

When I was a kid, my grandparents lived up in the mountains and we'd come out and I just always was really fascinated by the little things on the ground, actually, were my sort of first love.

Margaret Woodbridge is senior ecologist at the Bent Creek Experimental Forest southwest of Asheville.

She's in the place where science meets the soil.

She says with a disappearing canopy, that which doesn't belong quickly takes their place.

So invasive species come in and they take over an area.

They, in some cases, can kill trees.

But my biggest concern is the understory becomes dominated completely by maybe one or two invasives and you lose all that diversity.

Forests are more than trees.

Beneath the canopy on the ground lies what's called the understory.

Ferns, mosses and native plants, all vital to the ecosystem.

But Hurricane Helene changed everything, stripping entire mountain canopies off in a way scientists say they've rarely seen before.

And on an unprecedented scale, it's shifting the balance.

The conditions now are putting us kind of on a track to not return to normal, but maybe return to something completely different that we don't fully understand.

That might be a little scary.

Yes, it is scary.

And it's hard because of the scale and how do you begin to approach that?

So, for example, we see here our native flame azalea that's been taken over by oriental bittersweet.

And so eventually this shrub may die.

This right here?

Yeah, so this is the bittersweet.

And we see these orange flowers.

This is that native flame azalea.

It's a beautiful native shrub.

But the bittersweet has almost completely overtopped it.

It just wraps itself around the...

When forest canopies fall, sunlight floods the ground.

And what begins as light can lead to the gradual elimination of the forest's natural identity.

So we're looking at violetwood sorrel as a native.

And the concern here is that beautiful natives like this are going to be outcompeted by invasives like the multiflora rose we see right beside it.

This is multiflora rose, an invasive introduced to the U.S. in 1867.

So this is a southern red oak.

It's going to take quite a bit of time for seedlings that are this small to move up into the canopy.

Depending on the species, some, that high light environment allows them to grow more quickly.

And some really struggle because they're either outcompeted by those species that grow really fast, or they just struggle in that higher light, usually drier condition in the soil that's created by that loss of canopy.

I really like the kind of petals with the almost fringy red petals.

It's a little bit sticky.

It's very hairy.

We have thousands of native plant species, so I can't imagine how many we have overall.

I think just in the Smokies, there's at least 140 native tree species.

And the trees cradle about 1,600 native plants and around 200 bird species, along with a range of woodland animals.

They all depend on their own formula for survival.

Woodbridge says you don't even need a total canopy loss.

Even small disturbances in the forest can invite newcomers that overshadow these native species and slowly reshape the ecosystem from the understory up.

You'll see species that like different light environments because that smaller gap creates different lights environments, like spots of high light, spots of low light, wetter spots, drier spots, so you get that diversity.

You don't necessarily get that when you have just kind of a completely simplified condition.

So we're seeing a couple of invasives here, and it's a good example of some of the most concerning ones.

So we've got Multiflora rose here, and that's the white flowers you see coming up on the tree.

We have English ivy also growing well up into the tree.

And if you look up, you can start to see how expansive and kind of prolific the Multiflora rose and the English ivy are.

[music] In the mountains, survival is not solitary.

Trees, plants, animals are all connected within a complex system where every living thing depends on another, and nothing thrives alone.

I guess we're all part of it, aren't we?

Yeah, I mean, we're a part of these systems, and part of our job is to look at how to manage them.

Helene scares me because that makes that job so much harder.

But there is hope.

By studying which trees can return and where, they're testing ways to slow invasive spread and help native species recover.

And maybe that quiet promise of recovery, like the forest, begins from the ground up.

[somber music]