[gentle ambient music] - Hi there, I'm Frank Graff.

Ghost forests are appearing on North Carolina's coast.

Sounds scary, doesn't it?

Well, it is.

What ghost forests are and what they mean coming up on Sci NC.

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[warm music] - [Narrator] Additional funding for the Sci NC series is provided by GSK.

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Maritime forests are turning into ghosts forests because rising seas and higher storm surges, all caused by climate change, are pushing saltwater farther inland.

And that poisons the soil even far from shore.

Take a look at this photo.

It's from 430 miles up.

It was taken by NASA's Landsat satellite.

Researchers at Duke compared 35 years of such photos and found that between 1985 and 2019, 11% of the tree cover in the Albemarle-Pamlico Peninsula was lost to ghost forests.

Most of the land is in the Alligator National Wildlife Refuge.

Our friends at Science Friday take us into a ghost forest.

- [Emily] A ghost forest is a very clever name for a kind of unfortunate new habitat type we're seeing growing on the coast.

And it's a place where you have a lot of dead trees, large areas of contiguous forest that are just gone.

- [Ryan] My emotional response is to mourn the loss of those trees, but scientifically, I say what was the combination of stresses that caused this particular stand of trees to bite the dust?

- [Marcelo] We've been doing this now for close to a decade and in that time, we've already been seeing changes.

If these things are changing on a timescale where I can see it, what's gonna happen for this landscape by the time my kids grow up?

My name is Marcelo Ardon and I study ecosystem ecology and biogeochemistry of streams and wetlands.

- [Emily] And I'm Emily Bernhardt and I am a biogeochemist and aquatic ecologist.

- [Ryan] And I'm Ryan Emanuel and I'm a hydrologist.

- Believe it or not, back in 2004, this was a really large 440-acre farm that was purchased by a group of developers who decided to turn it into a wetland.

Because we were studying this wetland restoration project, didn't even occur to us that saltwater would get here.

And we recognized the year after the first intrusion event happened that we had gotten to near brackish conditions in much of this wetland.

- And that's what kinda led us into this research of saltwater intrusion and trying to understand if the patterns we had seen in this restored wetland were also happening in the broader area of the Albemarle-Pamlico Peninsula.

- The Albemarle-Pamlico Peninsula is a landscape that's dominated by water.

- [Emily] So we have the Pamlico Sound in the south and the Albemarle Sound in the north.

We have the big Alligator River sorta cutting down through the middle of this peninsula.

- [Marcelo] Ecologically speaking, this used to be all dominated by wetlands, tends to have very organic, rich PD soils, and it's a system that would sequester a lot of carbon in the soils.

- The Albemarle-Pamlico Peninsula has a history of large-scale commercial agriculture, vast tracts of land that are used for corn, soybean, crops like that.

No matter where you go on the peninsula, you can see some type of artificial drainage infrastructure.

- [Marcelo] You can even use Google Earth and Google Maps and you can see some of these changes on your computer.

- Even though they were made to drain water from the interior out to the estuary, there's the potential for them to serve the opposite purpose.

You can have storms that push saltwater deep into the interior, often through ditches and drains that may not have flow control structures or other protective measures.

- Now, when you have a drought, the sounds get saltier in part because they're evaporating and in part because they're not getting fresh water off the landscape.

So you start to see those salts mixing up.

- [Ryan] You could actually have gradients of saltwater that penetrate deep into the interior through these ditches and drains.

One of the impacts of climate change is a likely increase in the number and severity of droughts and the intensity of storms.

And both of those cases were actually influencing different types of saltwater intrusions.

- The thing that's actually happening is that salt is getting into a landscape and killing individual organisms, be they trees or microbes.

So it's actually happening at a very granular scale.

But what we wanna know, and I think what most would wanna know, is how the coast of North Carolina is going to change as a result of saltwater intrusion.

Our team is a hydrologist, two biogeochemists, a plant ecologist, and a social scientist, all trying to think about how can we bring our expertise to bear in this really multilayer difficult question.

- [Ryan] We're collecting data from more than a dozen sites around the peninsula.

- [Marcelo] So we measure the water chemistry, we measure the water level, nutrients are there, how much salt is in there.

We also monitor the soils, the chemistry of the soil.

We'll look at the greenhouse gas emissions.

And then we've also started measuring greenhouse gases from trees.

Is the tree functioning like a chimney?

So is it taking gases that are being produced by microbes in the soil and releasing them out into the atmosphere?

Or is it more like a cork and is it actually helping to keep gases that the microbes are producing in the soil within the soil?

- [Ryan] All of these things are monitored continuously at a handful of sites around the peninsula.

But we also have handheld tools that we can use to make spot checks as we drive around broadly.

- What we would really like to do is link what we're seeing with vegetation, areas where we know there's saltwater intrusion occurring, to what we're seeing in the soil.

So yes, there's salinization here, this is what the trees do when that happens.

- [Marcelo] Using geospatial data, we can try to see if what we see in these small places are gonna apply to a much larger area.

- We're currently using digital elevation models to assess how vulnerable the landscape is to saltwater intrusion.

We're using these algorithms that tell us how water concentrates and flows across the surface and how connected or disconnected different parts of the landscape are to one another, combining those metrics in ways that allow us to come up with an estimate of vulnerability.

And when I look at those maps, I get a sense of the magnitude of this problem.

Some of those salts can stay behind in the soils, so you may see reduced yields in crops and there are forests nearby that could be one of the factors that leads them to become ghost forests.

We think that ghost forests are spreading throughout the Albemarle-Pamlico Peninsula and throughout many parts of the Eastern US.

The pace of sea level rise and the intensity of human modification of the landscape have accelerated that process.

I've never worked on a project where the change is happening at such a rapid timescale.

- It is possible that we might not fully understand this problem before it's too late.

So this area is actually one of the highest sea level rise rates in the country.

- You could be very fatalistic and say just let it go underwater.

And I think that would be unfortunate if that's the decision that we make.

There's the enormous standing stock of carbon in the trees and the soils of all these coastal wetlands that could be lost back to the atmosphere.

And then there's the biodiversity loss.

If we lose these so fast, we're just gonna lose this really important eco region.

Where we can be hopeful is that there are a lot of things that we could do to manage this landscape differently than just abandoning it to the sea.

- One of the things we hope to do with our research is to provide decision makers with tools that they can use to potentially mitigate some of the effects of saltwater intrusion that are caused by ditches and drains.

- Rather than it being an on or off switch where it has to be either we build a ditch or we plug it, can we find ways where we allow water to move in one direction but not maybe allow it to move in another direction?

Or even maybe trying to figure out if there are maybe crops that would be more salt-tolerant that are growing out here.

And the same thing for these wetlands, so restoring it to what used to be here historically is probably not gonna be the smartest idea.

And starting to think about what species are gonna do well, can we use those species for restoration?

- If we do nothing and we continue to farm, we continue to build infrastructure as if these forests and these systems are not going to change, then we might be in for some really rotten surprises in a few decades.

- [Emily] I think humans can have a huge impact on both whether new ghost forests develop, whether current ghost forests expand, and also what happens now once a ghost forest exists on a landscape.

Do we leave them?

Could we manage them in a way that we might actually move more rapidly into a sort of a salt marsh ecosystem?

I think there's a lot of interesting decisions that we could begin to make.

There are not gonna be forests in those places probably again, but there might be something equally interesting and beautiful.

[futuristic ambient music] - [Narrator] Do you want to explore more cool science facts and beautiful images of North Carolina?

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[logo whooshing] - Think back to when you woke up today.

Chances are it was just something like this.

[alarm blaring] It turns out alarms aren't the only thing that are loud in the morning.

Duke University researchers have discovered why birds sing so loudly in the morning.

[trumpet blaring] [drums beating] Before the audience takes their seats, [lively keyboard music] before a band takes the stage, [piano keys tinkling] there's a warmup time.

[flute whistling] Call it a brief final rehearsal.

- [Drummer] Is it okay to tune right now?

[piano keys tinkling] - [Frank] Play those difficult notes and phrases one last time.

[drums beating] Play rough now [bass twanging deeply] to play well later.

[sparrow trilling] It turns out musicians and singers aren't the only performers who warm up before putting on a show.

[sparrow trilling] - This burst of song early in the morning happens to correspond with these birds getting better at singing their particular songs.

It's like a musician warming up because the action is later on.

[sparrow trilling] - [Frank] The performer in our story is the swamp sparrow.

- Swamp sparrow sounds are what we call trills.

And so basically, they're reaching from really low notes to really high notes.

And they repeat that note over and over and over again.

[sparrow trilling] They have to open their beak really wide to get these really, really big sweeping trills.

To go from really low notes to really high notes.

And that's something that's pretty difficult to do, especially when you're singing these notes over and over and over again.

- [Frank] And those trills are really tough to do without warming up first.

[sparrow trilling] Duke University biologists discovered that just before dawn, male swamp sparrows sing loudly and as much as possible to warm up.

[sparrow trilling] - So how a song is difficult to perform is first, how big of a range of pitches can it reach?

And then second, how quickly can it trill that range?

But if you wanna reach a really wide range of pitches, you have to open your beak really wide, something like this.

- [Frank] Scientists say some of the swamp sparrow's songs are fight songs to defend territory.

But most are love songs to find a mate.

- The metric that we use combines the trill rate, so that's how quickly can a bird open and close its beak, with its frequency bandwidth, which is how wide is the range of pitches during a single note reaching to create this metric that we call vocal deviation.

And that's a really good metric of figuring out how physically challenging a song is performed.

[sparrow trilling] - [Frank] The data was clear, warming up works wonders.

[sparrow trilling] - The birds are improving this vocal deviation metric.

And you can, sometimes you even see it when you're looking at the song, you're listening to the song that they get longer and you can see the pitches getting wider.

When we analyzed all 2000 songs, it showed up to be a very, very clear trend that the songs are getting faster and reaching lower and higher pitches as they sing throughout the day.

[sparrow trilling] - The females are really interested in the quality of the song performance.

They really pay attention not just to how much a male bird sings but to how well he sings that song.

[sparrow trilling] And it's like their backstage and they're waiting for the curtain to go up and the curtain goes up and they've already warmed up and then they sound as good as possible.

And that's gonna be as attractive as possible for the females who are listening.

[futuristic ambient music] - [Narrator] Wanna take a deeper dive on current science topics?

Check out our weekly science blog.

[logo whooshing] - You will find that, ugh, frightening-looking creature pretty much anywhere there's a little water.

One of the nation's leading experts on mosquitoes is at Western Carolina University.

- [Brian] So these are rearing chambers where we keep different species of mosquitoes.

So here we have the Eastern tree hole mosquito or Aedes triseriatus and this is a rock pool species from West Texas called Aedes epactius.

There's males and females flying around in there.

There's cups where we're rearing up the immature stages, the larvae and the pupae.

- A mosquito is a mosquito to most of us, it's one of nature's most irritating pests.

You're fascinated by mosquitoes.

What is it about a mosquito?

- Well, I mean, I think we'll show you some under a microscope and they can be, for lack of a better word, beautiful.

I mean, there's a lot going on with these mosquitoes and think about something so small that has a complex life histories and is responsible for such a large burden of disease worldwide.

I think you have to respect it.

- [Frank] But professor Brian Byrd has a unique perspective.

- So they're attracted to many different cues and some of this is still, we're still figuring this out, but it can be things like what colors you're wearing, body size, human odorants, but a predominant one is carbon dioxide.

And so they'll cue into that carbon dioxide and find their way close to you.

- [Frank] He supervises the Mosquito and Vector-Borne Infectious Disease Facility at Western Carolina University.

- If a mosquito is seeking a blood meal or attempting to get a blood meal, it is a female mosquito.

But both the males and the females, they both have to have sugar or nectar.

So they get those from plant juices.

But the female is the one that'll blood feed.

Not all species of mosquitoes blood feed.

The males are only sugar feeding or nectar feeding.

The females are generally doing both.

They need that nectar to sort of get along day to day to day and then they need that blood to lay their batch of eggs.

So the blood's a really important source of nutrients for egg-laying.

- [Frank] Roughly 60 species of mosquito call North Carolina home.

Though the dark damp southern Appalachian hardwoods of the western part of the state are close to a heavenly habitat for a mosquito, The insects are found throughout the state.

And each insect has its own unique biology and habitat.

- So in the state of North Carolina, this mosquito right here is actually the one that's responsible for most disease that occurs in the state.

And this is the Eastern tree hole mosquito.

You saw this one in the insectary.

So I even appreciate the beauty of this particular species.

- [Frank] And where's the stinger here?

- So the proboscis, they don't really sting.

This is the feeding structure right here, so the proboscis.

And it's actually fairly complex.

This is a sheath covering multiple parts that sort of one part acts as a stilette and that's what sucks up the blood.

- So this right here is what is going to suck the blood?

- [Brian] That's right.

- And this is the wings, obviously.

The eye here, I think?

- [Brian] Yeah, their eyes are right there.

They're a little sunken in but they have compound eyes right here.

So this is the head.

This is the thorax.

So this is the top part called the scutum.

This is a side or lateral part.

And then this is the abdomen.

- [Frank] Okay.

- [Brian] And then six legs.

These are actually parts of the antenna.

So we have two antennal branches there.

These are called flagellomere, so those are different types of sensory structures.

It actually uses visual cues and chemical cues to sort of navigate that environment.

- [Frank] Byrd's research takes him into forests and fields and anywhere there is standing water for a brief time.

That's where mosquitoes lay their eggs.

These traps collect those eggs for study.

- What we have here under the microscope is an egg strip that we can place out in plastic cups full of water.

And mosquitoes will come by and they'll lay their eggs on this strip around the edge.

This big black mass is several individual eggs.

One mosquito, we'll often see lay a hundred or more and just a couple of weeks ago sampled from a rock pool beside a river.

And as far as larvae, it had more than a thousand mosquito larvae in it.

- [Frank] Byrd and his team want to learn how mosquitoes carry and spread diseases.

- [Brian] We actually have the mosquito-borne disease here called La Crosse encephalitis.

That is the most common mosquito-borne disease in North Carolina.

- [Frank] Those diseases are called vector-borne illnesses.

They are transmitted by carriers like mosquitoes, ticks, and fleas.

- This is a pretty common trap for mosquito surveillance.

- [Frank] But scientists not only analyze mosquito eggs and larvae for evidence of diseases.

- And it has on top a fan that sucks inward and we'll bait it with a lure.

- [Frank] They also collect live mosquitoes at monitoring stations.

- That we can preserve and test to see if they are carrying viruses.

- [Frank] Taken together, the information allows researchers to track disease-spreading mosquitoes and alert public health authorities.

- [Brian] So we like to think about the three Ds.

- [Frank] Drain, dress, defend.

The three Ds, Byrd's advice for staying mosquito safe.

- So if you have standing water around your house, the best thing to do is tip and toss that drain.

Then the next one is dress.

And so avoid areas of your skin that are being exposed to mosquito bites.

So if you notice you're having mosquito bites, just try to cover up.

And then the last one is defend and there are EPA and Centers for Disease Control-recommended repellents.

And you can dial in which repellent is best for you based on the activities you're doing.

[futuristic ambient music] - [Narrator] Hey, parents, teachers, and homeschoolers.

Looking for lesson plans?

You'll find free interactive ones about all types of science covered by Sci NC online.

[logo whooshing] - Time now to meet the real gymnast of the insect world.

And it's not a mosquito.

Scientist, Adrian Smith, with the North Carolina Museum of Natural Sciences, introduces us to the psyllid.

- This little bug next to my finger is something called a psyllid.

The common name for these insects is jumping plant lice.

If you came across one, you might find it hanging out on a leaf like this.

And if you got too close and spooked it, this is the amazing thing it'd do to get away.

[gentle ambient music] No other type of insect throws itself into the air quite like plant lice do.

As an entomologist, I study insect behavior for a job.

But I have to admit, I had no idea how incredible jumping plant lice were until I started filming them.

The main reason people talk about and study these insects is because they feed on plants and can spread crop diseases.

Here's what you might see if you find them.

This is the underside of a leaf from a persimmon tree.

Here on the left is an adult and those fuzzy green oval things are the immature nymphs.

All that white dust on the leaf and the white frill all around the nymph is a wax they produce.

Here's a branch from a holly tree that's infested with the psyllid.

These clumps of folded up leaves are galls that have formed around where the young nymphs hide out and feed.

Here's one cut open with the tiny orange psyllid nymphs and their little clumps of wax.

And when I say tiny, these things are less than a millimeter in body length.

That's the tip of a mechanical pencil for scale.

But psyllids are way more than plant-sucking insects.

I think the most incredible thing about them is how they jump.

They use their hind legs to send themselves front flipping through the air.

And as far as I know, no other insect can do what a psyllid does.

Here are a few sequences I captured of their jumps by filming them at 3,200 frames per second.

[gentle ambient music] ♪ There's only been one scientific study that describes how they jump.

This study shows that they spring their hind legs down by rotating them at the base where they meet the body.

This is the same spring-loaded leg movement that other insects like spittle bugs and leaf hoppers use to power their jumps.

These insects are in the same order as psyllids, but their jumps are straight up off the ground, not flipping.

Extremely fast front flips are the most unique thing about the psyllid jumps.

To measure how fast they flip, I had to film their jumps using a specialized high-speed video camera.

I captured these two sequences at 14,000 frames per second.

The first one on the left completes its first flip at a rate of 389 flips per second.

The other on the right is a little slower doing only 212 flips per second.

The only animals that have been recorded spinning faster are springtails, but they flip backwards into the air by using a spring-loaded tail-like appendage.

There's no solid explanation for why psyllids take off front flipping like that.

It might be because they feed with their heads down, so they just take off in that same body position or it might be to maximize the unpredictability of an escape jump.

And some of them flipped a lot, spinning dozens of times several body lengths into the air.

[gentle ambient music] Others only flip a few times before they fan their wings out to stop the rotations and transition into a wing-powered flight.

It's pretty spectacular to watch them transition from flipping to flying in midair.

There are over 3000 described species of psyllids spread across eight taxonomic families.

And jumps have only been described for three of those.

So there's a lot left to study and learn about these organisms.

For instance, all the shots with this yellow background are a persimmon psyllid, which is in a family of psyllids that hasn't been filmed before.

So while I filmed everything you saw here, I collected a bunch of other not as nice-looking video to use for data collection.

So I filmed all this because I don't think psyllids get appreciated enough for what they can do.

I mean, I had no idea.

It's pretty incredible to me that a bug I can find in my backyard might be the fastest front flipping animal on earth.

These insects are a great example of how organisms all around us are doing incredible things, and a lot of them are still out there waiting for someone to notice and describe what they do.

[gentle ambient music] [futuristic ambient music] [logo whooshing] - And that's it for Sci NC, I'm Frank Graff.

Thank you for watching.

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- [Narrator] Additional funding for the Sci NC series is provided by GSK.