Discovery

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Archive for the ‘Ecology’ Category

The Slime that Saves the Planet

Washington State University researchers have received half a million dollars to study a microscopic slime that they believe plays an outsized role in life on the planet.

The slime, also known as biofilm, forms a super-thin layer gluing the roots of plants to mineral surfaces and serves as a reactor in which a plant can break down the rock for vital nutrients. The process, says Kent Keller, was central to the start of land-based plant life as plants invaded the continents 350 million years ago. It continues to take place on modern volcanic ground and receding glaciers—anywhere a plant can’t get enough to eat.

A special root slime helps plants like this pine tree pull nutrients from bare rock. Flickr photo courtesy of eviltomthai.

“The magic of all of this is plants come in that are adapted to make the slime,” says Keller, co-director of the Center for Environmental Research, Education, and Outreach (CEREO) and professor in the School of Earth and Environmental Sciences. “Within 100 years, you’ve got soil. That’s an amazing thing. And it’s these slimes that are a key part of the mechanism.”

Wait, there’s more: The biofilm reactor also facilitates the most fundamental process on the planet for packing away carbon, as seen in the greenhouse gas carbon dioxide. As the plant dissolves minerals, the plant’s natural carbonic acids, made from CO2 through photosynthesis, are transformed into bicarbonate that is carried in runoff to the oceans. There it precipitates as calcium carbonate.

In other words, the biofilm acts as an intermediary between carbon from the atmosphere and its storage in the earth’s crust. Absent that process, carbon dioxide would continue building up in the atmosphere until oxygen-dependent life forms suffocated in a “runaway greenhouse.”

“Without that we wouldn’t be here,” says Keller. “We’d be Venus, because Venus has no mechanism to sequester volcanic CO2.”

But there’s a mystery to the process, which Keller and a group of colleagues will explore with $492,000 from the National Science Foundation. Somehow plants employ biofilms to build up nutrients for plants to use while also releasing them for long-term storage, and they’ve done this in a way in which plants thrive and the chemistry of oceans and the atmosphere is kept in balance.

The researchers—a team of earth, life, and soil scientists—plan to grow trees in different nutrient conditions, including pure sand, to see which are best at inducing the formation of biofilm. One indicator of that will be microbial communities, which essentially generate the biofilms for shelter. The researchers hypothesize that plants in the worst conditions will be predisposed to hosting the most diverse microbial communities, the better to generate slime and nutrients.

One experiment will rely entirely on fertilized irrigation as a proxy for conventional agriculture, which is less reliant on large microbial communities for nutrients. Comparing this system with those generating their own nutrients could help open the door to agricultural systems that can use fewer artificial fertilizers.

Happy Anniversary, Mount St. Helens

Thirty years ago today, Mount St. Helens blew in one of the great natural spectacles of our time. The anniversary has launched several hundred retrospectives, many of which are highlighting work by Washington State University scientists.

In a piece for Voice of America news, Tom Banse visits with botanist John Bishop, who has spent decades studying the transition from sterile blast zone to habitat-rich ecosystem.

“What we’ve realized as we’ve spent a lot of time here and we’ve quantified the plants and the animals is that we actually have extraordinary levels of diversity here, of biological diversity,” he says.

Early morning sun on Mount St. Helens/Robert Hubner photo

In a Vancouver Columbian piece about preserving the mountain, Bishop encourages people to visit.

“There ought to be more people hiking out there, not less,” the newpaper quotes him as saying. “I think people ought to see the place. It’s wonderful. The recovery process is amazing, the vegetation is quite remarkable. It’s a very interesting place to visit.”

In a separate Columbian piece, reporter Erik Robinson explains how the blast created landscape patterns around the Toutle River similar to other, unexplained forms elsewhere.

Says John Wolff, WSU volcanologist and geochemist: “Almost as soon as that landslide had settled down, people said, ‘Whoa, this looks exactly like the corridor by Mount Shasta.’”

The coverage has a powerful alumni angle as well. The Daily News of Longview recounts how Trixie Anders, a WSU geology masters student, was riding up the mountain with Barry Johnston, her husband of the time, when at 8:32 a.m., “the event of a lifetime burst into our lives.” Turning around, the two outraced the plume of ash back down the mountain, barely.

For more on John Bishop’s work, see the Washington State Magazine piece, “Mount St. Helens: The perfect laboratory.”

Even Extremophiles Know When to Back Off

A few years ago, I was working on a story involving a somewhat personal fact of life for women. It was the sort of think most would feel uncomfortable about discussing for the Sunday front page of Washington’s largest newspaper. I wanted to talk about this fact of life with a high-profile and female captain of industry, so I called the assistant of a Seattle bank president. The response was quick but polite: ixnay on the intervieway.

When I mentioned this outcome to a fellow reporter, she said, “People don’t get to a position like that by taking a lot of chances.”

Malcolm Gladwell had a similar thesis in a New Yorker piece earlier this year, asserting that entrepreneurs–seeming swashbucklers of the capitalist set–actually prefer to take the cautious if not sure route to wealth. (You can read the top here.)

It turns out that one of  the most crazy seeming animals is a pretty risk-averse creature as well.

The extremophile sulfide worm lives on the edge, but not too on the edge.

This character is known to science as Paralvinella sulfincola. It’s an extremophile–one of several recently discovered microbes and animals capable of living in environments of seemingly unbearable heat, pressure and acidity.

In a paper just out in the journal Nature Communications, a Washington State University biologist and New Zealand collaborator ask just how harsh the sulfide worm might like things. It turns out, not too much.

Raymond Lee, an associate professor in the WSU School of Biological Sciences, and lead author Amanda Bates of New Zealand’s University of Otago tested inch-long sulfide worms found on thermal vents a mile below the ocean surface on the Juan de Fuca ridge off British Columbia. They placed the worms in aquariums with hot and not-so-hot sections and found that the worms made a point of going to the cooler areas, even if they could handle temperatures of up to 55 degrees C, or 131 degrees F.

“The surprising finding is they are very conservative,” said Lee, who explored the vents using the Woods Hole Oceanographic Institution research submarine Alvin on a National Science Foundation grant. “They have a high thermal tolerance, but they don’t prefer to be near that high thermal tolerance. That tolerance is more a safety mechanism.”

The finding rebuts speculation that surfaced in the mid 1990s that these types of worms live between 60 and 80 degrees C., or 140 to 176 degrees F. In separate experiments, Lee and Bates found none of the worms could survive above 60 degrees C.

Lee said the work gives some insight into how animals work and the more limited environmental extremes that multicellular organisms can handle.

It’s a lesson we can all take to heart. It may look like deep-ocean bugs, acid loving worms, and captains of industry love heat and pressure. But over the course of a lifetime or the run of a species, it makes sense to take it easy out there.

Read more about Lee’s work in the Winter 2006 Washington State Magazine.

Literally Morbid, Truly Fascinating

There’s just no getting around the fact that solving some of the world’s most persistent animal diseases can get a bit bloody. That’s quickly obvious in a visit to the Bustad Hall necropsy suite run by the Washington Animal Disease Diagnostic Lab.

Veterinarians on this visit are performing necropsies—animal autopsies, if you will—on three bighorn sheep that state wildlife workers shot outside Vantage. Veterinarians want  to see if they have been exposed to a bacterium suspected in the pneumonia killing sheep in the Yakima River canyon.

Photo courtesy of Barry Maas

“Not a real pretty place,” is how Charlie Powell, a vet school spokesman, describes the lab as he brings me and the Northwest News Network’s Anna King into a nearby viewing room. There lie three plainly dead bighorn sheep, their horns not all that big, the floor beneath them stained with wide streaks of blood. Over the next half hour or so, veterinarians and students essentially take the animals apart. They disarticulate a shoulder, cut through the ribs with long-handled pruning shears, remove organs, draw blood and gingerly bag sample upon sample of tissue.

It’s as if they are stripping a car for this accessory and that while leaving the bulk of the parts on a sheep rug. It isn’t exactly gross, and if you think it is you probably haven’t read this far. But it is literally morbid—these things are dead. And it is truly fascinating, particularly when one’s gaze moves to a quarter horse being dissected directly in front of the viewing room window.

Here is an animal so huge it has to be brought in on the room’s two-ton electric hoist, and it is unfolded to reveal a study of anatomy writ large—huge ribs, big liver, big intestines. Out of this, veterinarians can home in on the smallest, most banal killer. In this case, Jim Stanton, a clinical assistant professor, taps along the intestine and points out a hard section. A student slices it open and pulls out a softball-sized bolus. Better than a smoking gun, it is the soft, fibrous bullet that caused the colic that felled the horse.

WSU pathologists are now analyzing the sheep samples for an even smaller nemesis: Mycoplasma ovipneumoniae. WSU researchers found the bacterium in bighorn sheep from Hells Canyon just a couple of years ago, says Tom Besser, a professor of veterinary microbiology. They’re now finding signs of it in herd upon herd of pneumonia-plagued bighorn sheep. Besser says he doesn’t know if it is in this herd yet, “but that’s what I’m going to look for.”

Read and hear Anna King’s report, “Scientists Scramble To Save Northwest’s Iconic Bighorn Sheep”