STEVE INSKEEP, host:
We're learning more this morning about dust and about the trouble it causes. Billions of tons of dust blow off arid lands every year, leading to dust storms that make people sick, kill corral reefs, even melt mountain snow packs.
In the southwestern United States, dust storms are largely the results of tires and hoofs, which are destroying a natural biological barrier that once kept dust on the ground. In the second of two reports, NPR's Richard Harris met a scientist who is trying to restore that protective layer in the American west.
RICHARD HARRIS reporting:
You might call Jane Belnap, Dr. Dust. She's an ecologist who works for the U.S. Geological Survey in Moab, Utah. And one spring day, a scientist from Colorado named Tom Painter, decided to pay her a call in the red rock desert she calls home.
When the three of us meet in a parking lot off Interstate 70, Belnap's sporting a Charles Darwin T-shirt, a graying pixie cut, and a florid sense of humor...
Ms. JANE BELNAP (Soil Ecologist, United States Geological Survey): Hi, honey!
Professor TOM PAINTER(National Snow and Ice Data Center, University of Colorado): Did we hit this day right, or what? Jane, this is Richard.
Ms. BELNAP: Hi. How are you?
HARRIS: Pleased to meet you.
Ms. BELNAP: Yeah, this is a perfect day. Except it rained, so the soil's wet. That's why it's only sort of dusty.
HARRIS: You want to see what's really dusty, she asks? And she whips out a photo of the local highway during a serious dust storm.
Ms. BELNAP: You really can't see anything. And the only thing they did was put Warning - Dust Storm signs on the highway.
(Soundbite of laughter)
Ms. BELNAP: Great.
Prof. PAINTER: What exactly does that mean?
Ms. BELNAP: What exactly does that mean? What do I do when I hit this wall of black, knowing full well if you slow down you're going to get rear ended, and if you speed up you're going to die.
HARRIS: Belnap is a natural optimist, and she's facing a pretty grim situation. She says blowing dust actually kills people on the local highway, and it creates havoc around the world.
Ms. BELNAP: That havoc can be death of corral reefs in the Caribbean; that havoc can be people in Beijing dying from respiratory diseases. I mean, there's a lot of things in dust that are not great things to have floating around in the air.
HARRIS: And dust also settles on the snow. In fact, that's what Tom Painter studies and what has drawn him out of the Rockies to meet Jane Belnap.
Prof. PAINTER: This year we had a major dust deposition, and it crossed Colorado and into Wyoming, that created snow melt at a time when snow melt doesn't occur.
HARRIS: Dust makes the snow melt faster, and that affects how fast the water pours out of the mountains and feeds the rivers and reservoirs down here.
Jane Belnap says dust is the desert's little gift to the mountains.
Mr. BELNAP: Isn't it nice of us to share?
Prof. PAINTER: It's very generous.
Ms. BELNAP: I thought so, too.
Prof. PAINTER: And we're very grateful.
Ms. BELNAP: I'm so glad.
(Soundbite of laughter)
So what we're going to do is...
Prof. PAINTER: Where're we going?
Ms. BELNAP: ...just take this a little bit down the road just to stop and visit and fondle Manco shale.
HARRIS: Manco shale is the name of the geological formation here. It was a seabed in the time of the dinosaurs, and among other things, it's loaded with naturally occurring mercury and arsenic and other nasties that blow when the wind picks it up.
We head toward Moab, a one-time uranium mining center, now a tourist town. Even though Belnap says it's not so bad today, there is still a lot of dust in the air - and for good reason.
Ms. BELNAP: We just had Jeep Safari this weekend, which is when 10,000 Jeeps show up here and ATVs, and pretty much run all over the place. But when we have activities like that and then it doesn't rain for awhile we get huge dust production off the areas. Here's some of the Jeeps. They're (unintelligible).
HARRIS: They're streaming past us, leaving Moab it looks like.
Prof. PAINTER: Yeah.
Ms. BELNAP: Yeah.
HARRIS: Jeeps driving off-road break up a living barrier in the soil, a biological crust that normally keeps the dust from blowing. Cattle break up that crust, too. So do deer, which are much more abundant these days, because cattlemen made water available everywhere. Plus, a prolonged drought in the area has made a bad problem even worse.
We pull off the highway and Belnap drives to a place that's a natural experiment in restoring these lands.
Ms. BELNAP: Okay.
HARRIS: It's a buffer zone around an airport, so it's been fenced off from cattle and Jeeps for the past 20 years.
Ms. BELNAP: So this area is actually pretty stable, because - and this is what I wanted to point out to you. You can see the physical crust on the surface.
Prof. PAINTER: It kind of looks like a mud flat, almost.
Ms. BELNAP: It looks like a mud flat, but it's not blowing away. You know, you can look down there and you're not seeing anything really move for - off that soil crust. So even though it's a...
HARRIS: And it's really blowing out here!
Ms. BELNAP: And it's really blowing.
HARRIS: The surface here is still missing something important. It was disturbed many decades ago, but before then it was crusted with lichens and mosses and held together by a kind of soil bacteria called cyanobacteria. The irrepressible Belnap has a nickname for these life forms.
Ms. BELNAP: Let's go see crusties.
Ms. BELNAP: Yeah, yeah.
Prof. PAINTER: Biological crusties?
Ms. BELNAP: Yeah! They're the cutest things ever. I mean, like, way! You think your children are cute, ha!
HARRIS: No, no. No, algae is much cuter.
Ms. BELNAP: Dude, get a life.
Prof. PAINTER: Much cuter than your crusties.
Ms. BELNAP: No, no, no, no! They don't wave at you, do they? No. They lay there in the snow, frozen. Aaayyyy!
(Soundbite of laughter)
HARRIS: We pile back into the car and head around to the base of a hill. It's not as dramatic as the natural arches nearby, but the red and green striped rock is still a classic scene of the American west.
Ms. BELNAP: Ah, perfect!
HARRIS: This rocky hillside has somehow managed to escape the onslaught of cattle and jeeps.
Ms. BELNAP: Those are all crusties over there - that black surface. So let's go visit them.
HARRIS: We scramble up the rocks, taking care not to disturb the soil. Belnap picks up a sample.
Ms. BELNAP: So here's a really nicely developed soil crust. We have all those different colors are different lichens. We have mosses in here, as well; we have cyanobacteria. And this is absolutely stable from both wind and water erosion.
HARRIS: And it's...
Ms. BELNAP: Where's the what?
HARRIS: Where's the cyanobacteria?
Ms. BELNAP: Okay, cyanobacteria microscopic. See that little, those little filaments sticking out?
HARRIS: She holds up a clump of dirt. Another clump dangles from a tiny thread. These threads are produced by the cyanobacteria and do an amazing job of holding the soil together.
Ms. BELNAP: And there's bazillions of them. That's a technical term.
HARRIS: How long does it take for the biological crust on this soil to form?
Ms. BELNAP: Here, it's hundreds of years. The Mojave, it can be thousands.
HARRIS: And that has huge implications for what Jane Belnap really cares about; that is, restoring the biological crust on these disturbed lands. That's not only to help them recover, but to stop the blowing dust.
Ms. BELNAP: I hate giving up all my friends, and I'm giving up a lot of them in saying this. But, frankly, if we're going to use these lands, we're going to have to find some happy medium.
HARRIS: That happy medium would be to let the fast-growing cyanobacteria return to the soil and spread their threads to hold it in place, but not to expect the return of mosses and lichens.
Even reaching that happy medium could be difficult. The situation here in the west has gotten much worse in the past five years since drought set in. And climatologists say there are signs that this is just the start of a 30-year pattern known as a mega-drought. All the research on crusties was based on their life during wetter years.
Ms. BELNAP: We don't have any idea of how what we now know applies to the future, if it's going to be a lot drier.
HARRIS: But Belnap says if we are going to do something about dust, the biological crust here really does need a break from hooves and tires.
Richard Harris, NPR News.
INSKEEP: You can compare photos of healthy and dusty deserts by going to npr.org.
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