UW Stable Isotope Facility Secures Partnership to Analyze Soil Samples Nationwide

The University of Wyoming Stable Isotope Facility (SIF) is now the go-to laboratory to analyze soil samples from all across the country.

UW was recently awarded a National Science Foundation (NSF) grant. Craig Cook, SIF director, and Chandelle Macdonald, the laboratory’s manager, made the successful proposal to the National Ecological Observatory Network (NEON) to secure the three-year, $80,000 contract to analyze soil samples from the entire NEON network across the United States.

“We have an agreement with NEON to analyze soil samples from all over the country,” says David Williams, SIF faculty director and UW professor and head of the Department of Botany. “All soil samples are being sent to UW for carbon and nitrogen isotope analysis.”

NEON is designed to gather and synthesize data on the impacts of climate change, land use change and invasive species on natural resources and biodiversity. Using instrument measurements and field sampling, data are collected from 106 sites -- 60 terrestrial, 36 aquatic and 10 aquatic experimental -- across the U.S. and Puerto Rico. The sites have been strategically selected to represent different regions of vegetation, landforms, climate and ecosystem performance.

NSF created NEON Inc., a nonprofit organization, and is funding the project to the tune of approximately $434 million, Williams says. NEON, based in Boulder, Colo., employs its own staff, purchased all of its equipment and instrumentation, and collects soil, plant, water and animal samples for analysis.

In the lab

Under the contract, the SIF lab began receiving its first batch of soil samples -- from Alabama, Florida, Tennessee and West Virginia -- earlier this month, says Macdonald, who runs the lab and supervises two undergraduate students.

Soil samples, which will be delivered from all across the country, arrive in sealed glass tubes. The samples are initially sterilized by placing them in a drying oven and turning up the temperature to 110 degrees Celsius, which is akin to boiling water. Sterilization essentially kills the bugs that may be in the sample, Macdonald says.

Each sample is then placed in a tiny tin capsule and weighed accurately, out to one one-hundredth of a milligram, she says. Samples are then logged into a computer database.

“It takes more time to weigh the samples than it does to run the samples,” Macdonald says. “We’ve had three batches come in under the contract.”

After the soil samples are weighed, they are combusted in an instrument called an elemental analyzer. The elemental analyzer produces carbon dioxide and nitrogen gas, which are analyzed for carbon and nitrogen isotopes in an isotope ratio mass spectrometer.

“When you work with restricted soils, USDA has an entire set of rules to follow. There are controls,” Cook says.

Cook stresses that, whatever numbers the lab generates, that’s where its work stops.

“This is an analytical lab. It’s our job to generate the best numbers we can,” Cook says. “But, it’s not our job to interpret the data.”

However, he adds the analysis can provide clues to the current health of an ecosystem, such as a forest or swamp. This can be applied to a food web, which makes it possible to draw direct inferences regarding diet, trophic level (position an organism occupies in the food chain) and subsistence of animals, Macdonald says.

By looking at the carbon isotopes of animals, it can even be determined whether an animal feeds in its own environment or comes into town and finds food in garbage cans.

“Ecology and climate change is slow. They (NEON) may not see changes in 30 years,” Cook says. “By 2050, they should have a feel for whether changes are occurring.”

Feather in the cap

While the $80,000 contract will provide an infusion of funding for the lab’s operations, Cook says the national recognition is far more important.

“As the recipient of this award, UW’s Stable Isotope Facility has been recognized as one of the elite facilities for stable isotope analysis in the United States,” Cook says. “Those of us associated with this facility are extremely proud of this accomplishment.”

“UW is playing a very large role in the science of this country for ecologists,” Williams says.

After the three-year contract expires, Cook says UW could reapply for the contract or it could be extended by NEON.

Hear Director Craig Cook discuss the significance of the Stable Isotope Facility’s new NSF grant.