America's once abundant tallgrass prairies that once covered 150 million acres have rapidly disappeared, they were once home to free-running bison and contained hundreds of plant species. For the first time, researchers were able to look at the huge community of microbes that lived there as well.
"These soils played a huge role in American history because they were so fertile and so incredibly productive," Noah Fierer, a fellow at the Cooperative Institute for Research in Environmental Sciences (CIRES) and lead author of the study, said in a University of Colorado news release. "They don't exist anymore except in really small parcels. This is our first glimpse into what might have existed across the whole range."
The prairies' remarkable fertility may have been their downfall. Early settlers were attracted to the rich soil and planted intrusive corn, wheat, soybeans and other crops among the luscious prairies. The once-proud prairies now only cover a miniscule percentage of the land it once covered.
"It was very hard to find sites that we knew had never been tilled," Fierer said. "As soon as you till a soil, it's totally different. Most gardeners are familiar with that."
The research team was able to collect soil samples from 31 different sites. They performed DAN sequencing to characterize the microbe community in each sample.
"We have these soils that are dominated by this one group that we really don't know anything about," Fierer said. "Why is it so abundant in these soils? We don't know."
Verrucomicrobia were found in each sample, but there were differences across the sites. The team built a model to look out how the microbial population may have varied across the prairies.
"I am thrilled that we were able to accurately reconstruct the microbial component of prairie soils using statistical modeling and data from the few remaining snippets of this vanishing ecosystem," Katherine Pollard, an investigator at the Gladstone Institutes in San Francisco and a co-author of the paper, said.
The researchers hope to one day use Verrucomicrobia in prairie restoration efforts.
"Here's a group that's really critical in the functioning of these soils. So if you're trying to have effective prairie restoration, it may be useful to try and restore the below-ground diversity as well," Fierer said.
*This article has been edited to include a change.
