By Emily Stone, Antarctic Sun staff
image: Tsoil biologist Byron Adams adjusts a bundt pan filled with marbles that catches blowing dirt along the shore of Lake Hoare.
Byron Adams made his way up a slope in the McMurdo Dry Valleys recently, adjusting a series of bundt pans filled with marbles and a screen used to catch blowing dirt.
The low-tech equipment is not what made the excursion so remarkable. Nor the frozen lake, tumbling glacier and jagged peaks that created his backdrop.
What’s most unusual is that it wasn’t even Adams’ experiment. After using the bundt pans for eight years to look for microscopic organisms in the soil, his group turned the pans over to another science team that’s testing for carbon. Adams was in the area collecting samples for a different study and offered to do some maintenance on the pans.
Such cooperation typifies the Dry Valleys Long Term Ecological Research (LTER) Project. The 13-year-old project is made up of seven separate field groups that work cooperatively to better understand the area’s unique ecosystem. It’s a textbook example of an interdisciplinary approach to research in a world where many scientists are trained to be independent and protect their turf.
“You don’t usually see this many big shots who work together and like each other,” said Adams, of Brigham Young University and a member of the soil research group. “They produce something bigger than themselves by doing that.”
By combining their data and ideas about the soil, streams, lakes and glaciers, the LTER scientists have determined that the Dry Valleys are extremely sensitive to environmental changes. A slight change in temperature affects lake levels, stream flow and soil biodiversity.
“Small changes from a temperate perspective are really amplified in this system,” said Berry Lyons, lead principal investigator of the project and a geochemist from Ohio State University.
The Dry Valleys LTER is part of a larger LTER network of 26 sites, primarily in the United States. Each site is made up of interdisciplinary science groups that share information to understand their site. The network also allows for comparisons between sites, with the goal of understanding broader truths about Earth’s ecosystems.
Each LTER site also conducts long-term monitoring. About two-thirds of the Dry Valleys groups’ budget is spent doing the same tests and measurements in the same place each year, Lyons explained.
This creates a historical record of climate change in the valleys and at all the LTER sites that scientists can turn to, Lyons said, “as people have woken up and say, ëgee, the planet is in really bad shape.'”
A new approach
Robert Wharton started studying the lakes in the Dry Valleys in 1979 as part of a group trying to understand the ecosystem. His research there off and on over the next 10 years convinced him that it would be an ideal location for an LTER site.
The information scientists learn in simple ecosystems like the Dry Valleys can shed light on what is happening in more complex systems that are harder to study because they have so many more components. Wharton said he also felt strongly that the LTER’s method was the best way to study the Dry Valleys.
“In my opinion, ecosystem research just isn’t possible without an interdisciplinary approach,” Wharton wrote in an e-mail. He is now vice president of academic affairs at Idaho State University.
Even before the actual LTER grant was approved, the various scientists in the Dry Valleys were supporting each other when possible.
Diane McKnight of the University of Colorado at Boulder, and principal investigator of the stream group, remembers early efforts at helping one another, such as searching out a helicopter window for Wharton’s equipment so she could switch out the data recorders.
She also remembers watching lake and stream levels change dramatically from year to year.
“We could see how the Dry Valleys were changing before our eyes,” she said. And they could see the need for a long-term study.
Wharton approached McKnight, John Priscu, and Diana Wall, who had all been conducting research in the Dry Valleys, about forming the first LTER team. He also contacted a few other scientists, like Lyons and Andrew Fountain, who had been working elsewhere in Antarctica. The group was awarded an LTER grant in 1993.
Five of the original eight principal investigators are still with the project 13 years later, and one of the other current principal investigators started with the group as a collaborator. That’s a better track record than a lot of marriages, Lyons said. “It’s kind of amazing.”
When the group started out, the polar desert ecosystem was mostly a mystery.
For example, the soil in the valleys was assumed to be barren everywhere except in the streams when Wall started working there in 1989. Now, her group’s work has shown that microscopic worms called nematodes live in 60 percent of the valley’s soil. They’ve also learned that when nematodes sense a reduction in the soil moisture, they coil up into a dehydrated state.
“They no longer look like a worm. They look like a Cheerio,” she said. Then, when moisture returns to the soil, the nematodes become worm-like once again.
The principal investigators needed several years to figure out how the LTER system worked, as well. Wharton said some of the principal investigators held onto the idea of having separate turfs during the first few years.
Lyons said that a typical, three-year National Science Foundation grant isn’t long enough for scientists to maximize interdisciplinary collaboration. It takes a while for researchers from different disciplines to understand each other’s language and approaches, he said, and to gain the important and intangible respect for one another that is necessary for true collaboration.
The point when the group really hit its stride is marked by a spike in the number of co-authored journal articles in 1997, four years into the project. The number roughly doubled from the previous year, doubled again the following year, and has stayed high since.
The sophistication of the groups’ questions has grown over the years as they become more familiar with the area, Lyons said.
The LTER funding is done in six-year cycles, and each cycle has a theme. The first funding cycle’s theme was basically to understand how the physical constraints of the environment shape the ecosystem. Now, in the first year of the third funding cycle, the project is focusing on biodiversity in the valleys, as well as the individual carbon, nitrogen and phosphorus cycles and how they’re connected among glaciers, streams, lakes and soil.
Some of the different science groups within the project have studied this, but they haven’t done so in a way that relates to each other, Lyons said.
“We felt that we were losing information because we weren’t doing it in a systemwide approach,” he said.
Collaboration
Michael Gooseff sat down at the edge of a stream leading into Lake Fryxell earlier this month to take a break from the day’s work. He was there to help with a complicated experiment that one of McKnight’s graduate students was conducting.
Not that long ago, Gooseff was one of McKnight’s students. Now he’s at the Colorado School of Mines and is principal investigator on his own project looking at the wet soil zone around streams. Having come of age within the LTER, he said he’s always been a proponent of the interdisciplinary approach to studying ecosystems.
“I’ve been sort of born with that perspective. “It’s the one that makes the most sense in environmental science,” he said. He’s teamed up with a microbiologist and biogeochemist for his project, and although his project isn’t part of the LTER, he works closely with the LTER scientists to keep abreast of one other’s findings and exchange data. He often uses the LTER’s meteorological data to correlate weather and stream flow.
Many of the project’s principal investigators point to this trickle down effect among the LTER’s students as one of the project’s main benefits. LTER students go on to lead their own projects and mentor a new batch of young scientists.
“It’s changed the training of graduate students,” McKnight said.
More than 175 undergraduate, graduate and postdoctoral students have worked with the Dry Valleys LTER groups. The scientists try hard to impart the importance of collaboration to these students, Lyons said, as opposed to the training that most scientists receive.
“We’re trained that you have to stand on your own two feet,” which at its most extreme teaches scientists to be “narcissistic,” Lyons said. “Now the world is an interdisciplinary world, and we don’t train them very well to work in groups.”
The LTER’s scientists share information and data both formally and informally. The Dry Valleys principal investigators meet each spring to give a presentation of their research and list their priorities for the coming year. They also correspond regularly during the rest of the year, and those who are at McMurdo Station or in the field together chat about their ongoing research.
All of the groups’ data must also be in a manageable form and available through the LTER network within two years. The data sets can be queried by scientists from that site, from across the network or others interested in the information for their research.
The collaborative nature of the project doesn’t eclipse the fact that the group is made up of leading scientists with strong egos, who all spend a good portion of their work on independent research, Lyons said. He admits that much of his time as lead principal investigator is spent “herding cats.”
Still, Lyons paused several times while talking about the close friendships within the group to choose just the right words, and said he was getting goose bumps talking about it.
“I’ve learned so much from these people,” he said. “It’s been a great joy.”
Data shows rapid change
It was at one of the spring principal investigators meetings several years ago that the group realized they’d spotted a trend, Wall said.
The lakes group said the water levels had dropped and the ice layer had grown, and that primary productivity in the water was decreasing. The stream team said flow had fallen off. And the soil team was recording lower biodiversity. All this had happened between 1986 and 2000 when the average temperature had fallen by 0.7 degrees Celsius.
Seven of the principal investigators co-authored a 2002 article in Nature, detailing this phenomenon, and emphasizing the delicate nature of the ecosystem.
“Summer temperatures are the critical driver of Antarctic terrestrial ecosystems, and our data are the first, to our knowledge, to highlight the cascade of ecological consequences that result from the recent summer cooling,” the paper reads.
The Dry Valleys are so sensitive to climate change because temperatures hover so close to 0 degrees Celsius in the summer, Lyons said. Just below freezing means lots of ice, just above means more water. The group has learned that the number of days and even hours spent above freezing in the summer can rapidly change biomass and biodiversity there, Lyons said.
“There’s a direct and immediate response by the ecosystem to what’s going on climatologically,” he said. “How far can you push the system – til it changes?”
NSF-funded research in this story: Peter Doran, University of Illinois at Chicago; Andrew Fountain, Portland State University; Bill Hunt, Colorado State University; Berry Lyons, Ohio State University; Diane McKnight, University of Colorado at Boulder; John Priscu, Montana State University; Ross Virginia, Dartmouth College; Diana Wall, Colorado State University; www.mcmlter.org.
