The Iowa State University researchers led by limnologist (lake scientist) John Downing found constructed ponds and lakes located on farmland in the United States bury carbon at a much higher rate than expected -- as much as 20 to 50 times the rate at which trees trap carbon. In addition, ponds were found to take up carbon at a higher rate than larger lakes.

"Aquatic ecosystems play a disproportionately large role in the global carbon budget," Downing said.

"Despite being overlooked in the past, it's small bodies of water that are important because they take up carbon at a high rate and there are more of them than previously thought. The combined effect is that farm ponds could be burying as much carbon as the world's oceans each year."

The team, which included scientists from Europe and Canada, reported their research in the Feb. 15 issue of the journal Global Biogeochemical Cycles.