美国国家公共电台 NPR Spring Is Springing Sooner, Throwing Nature's Rhythms Out Of Whack（在线收听）

RACHEL MARTIN, HOST:

The warming climate means some dramatic changes - more floods, intense wildfires, extreme heat, other changes you may not notice as much. As part of our Summer Series, NPR's Nathan Rott reports from the Rocky Mountains where rising heat is disrupting the very rhythm of the natural world.

NATHAN ROTT, BYLINE: Up here in the high, alpine landscape of Colorado - a place that evokes the opening scene of "The Sound Of Music," with granite peaks and flowery meadows - seasonal rhythms always start with this...

(SOUNDBITE OF WATER DRIPPING)

ROTT: ...The melting of winter snow. As the snow recedes, earth thaws, and plants grow. Flowers bloom, and trees fill out with leaves.

(SOUNDBITE OF WIND BLOWING)

ROTT: Then come birds...

(SOUNDBITE OF BIRD CHIRPING)

ROTT: ...Pollinators like butterflies and bees...

(SOUNDBITE OF BEE BUZZING)

ROTT: ...Each evolved to play its own role in this interdependent dance. But in a year like this when the snowpack is low and temperatures soar, that snow melt happens faster and earlier than normal.

(SOUNDBITE OFSOUNDBITE OF WATER DRIPPING)

ROTT: And that whole natural cycle can get thrown out of whack.

DAVID INOUYE: So there's one, two, three, four...

ROTT: David Inouye knows this better than most. He's one of the world's leading experts on phenology - the study of these seasonal events.

INOUYE: It might be, when do flowers come into bloom? When do migratory birds arrive? Anything that has a seasonality to it, you can measure the phenology.

ROTT: Inouye's specialty is flowers. He's been studying them here at the Rocky Mountain Biological Laboratory some 9,000 feet above sea level for more than 40 years, doing basically what he's doing now - crawling on a hillside cataloguing flowers.

INOUYE: We've now counted - oh, coming up probably on 5 million flowers over the years.

ROTT: When he started, Inouye says, climate change wasn't really a thing that people were talking about. He was just interested in how flower abundance and timing varied from year to year. And there is a lot of variance. As we all know, some years, winter drags on and on; others, it's a relative blip. But Inouye says a larger trend is evident.

INOUYE: Spring is happening earlier. Despite all the variation from year to year, on average, the spring is getting earlier.

ROTT: This is true across the Northern Hemisphere, and it has dire consequences for agriculture and meadows like this. Plants, taking their ecological cue, are sprouting sooner, leaving them vulnerable to late-season frost - the remnants of a winter ended too soon.

INOUYE: Here's one that probably got frosted.

ROTT: And that has a ripple effect. In a windy, green meadow, Michael Stemkovski digs through a bag of plastic vials.

MICHAEL STEMKOVSKI: These are vials that we collect our bees in.

ROTT: Stemkovski is part of the bee team at this research station. He and two others, Matt Turnley and Rebecca Irwin, stand next to a flowering purple lupine equipped with wispy butterfly nets. They're aiming to catch as many bees as they can over the next hour to get an idea of how different populations of native bees are doing. And it's not exactly hard.

STEMKOVSKI: There's a bee.

ROTT: With a lunge, Stemkovski puts the net over a flower and then waves it back and forth through the air, ferrying the bee into the pointed end tip of the net.

STEMKOVSKI: That right there is a small bee...

ROTT: Oh, wow, it's tiny.

STEMKOVSKI: ...What's called a sweat bee.

ROTT: It's almost like an ant.

STEMKOVSKI: Yeah. If you look at the underside, there's all that yellow right there. That's pollen that it's spent this morning collecting from these yellow flowers.

ROTT: This is what's supposed to happen. Bee gets pollen. Flower gets pollinated. But by the end of the count, it's clear that there are fewer worker bees buzzing around than normal. Irwin, the leader of this group, says that some bees are able to adapt to changing rhythms. In a hot, dry year like this when flowers bloom early, they can adapt to meet those changes.

REBECCA IRWIN: But some of them are constrained by how long it takes them to develop.

ROTT: They can't emerge earlier. It's just not in their DNA. So those bees and the flowers that depend on them are gradually getting pushed out. Stemkovski says documenting the change can be disheartening.

STEMKOVSKI: It's kind of like watching an illness progress, you know, without having the tools to remedy it.

ROTT: The flexibility of a species to adapt to its circumstances, its ability to roll with the environmental punches, so to speak - scientists call that a species plasticity. Jill Anderson, who studies the plasticity of native plants in these Alpine meadows, says many of them are hitting the limits of that adaptability. We catch her hiking back from a field site.

JILL ANDERSON: Climate change is moving too fast for many populations to adapt in the sort of rapid fashion that they would have to.

ROTT: There are species that can adapt, though - species with a lot of plasticity that are emerging as winners. Some that you cheer for...

(SOUNDBITE OF YELLOW-BELLIED MARMOT CHIRPING)

ROTT: ...Like the yellow-bellied marmot...

(SOUNDBITE OF YELLOW-BELLIED MARMOT CHIRPING)

ROTT: ...A relative to the groundhog that is unspeakably cute - but others, Anderson says, that are a little less lovable.

ANDERSON: Like poison ivy...

ROTT: ...Ticks, pine beetles and mosquitoes. A few of the biologists at this research center said they'd seen more ticks this year than they'd ever experienced in the past. Dan Blumstein, who heads the marmot research here, says jarring changes are happening now.

DAN BLUMSTEIN: There's a conservation biology idea called shifting baselines. And the idea is that you sort of imprint on something maybe when you're a kid or when you first explore an area, and you think that's how it should be. And I'm 54 now. Baselines have shifted, and you see them shifting, and it's really freaky.

ROTT: To get an idea of just how much further these baselines might shift, we hike into one of the longest-running climate experiments in the world with ecologist John Harte. His experiment is a preview of what's to come.

JOHN HARTE: And it's pretty grim.

ROTT: Harte walks us past flowers and trees to a wide ridge where a series of long, metal heat lamps are suspended by wire a few feet off the ground.

HARTE: Reach underneath.

ROTT: Oh, yeah.

HARTE: Yeah.

ROTT: It's definitely hotter.

HARTE: Yeah.

ROTT: These lamps, Harte says, have been on day and night for 28 years, raising the temperature on the ground below by about 4 to 5 degrees.

HARTE: And that's comparable to the climate we expect around the year 2050.

ROTT: The ground beneath the lamps is remarkably different. The yellow and purple flowers that dot the meadows around us are mostly gone. In their place is gnarled sagebrush, a prolific plant that you'd usually see at far lower elevations. Hiking again in the thin mountain air, Harte says heat is reshaping the planet.

HARTE: So when I tell people what to expect, I say, well, imagine the opening scene of "The Sound Of Music" was filmed outside of Reno, Nev., because that's what it's going to be.

ROTT: And it's going to be that way, he says, faster than most people think.

Nathan Rott, NPR News, Gothic, Colo.

(SOUNDBITE OF FAIT'S "SOLACE")