Campus News

Researchers: Trace element plays important role in tropical forest nitrogen cycle

A new paper by researchers from UGA and Princeton University sheds light on the critical part played by a little-studied element, molybdenum, in the nutrient cycles of tropical forests. Understanding the role of molybdenum may help more accurately predict how tropical forests will respond to climate change. The findings were published in the journal PLoS ONE.

Nutrient cycles track the movement of essential nutrients as they loop through the environment, into plants and animals and back into the environment One of the most important of these nutrients is nitrogen.

“The main way that new nitrogen is added to an ecosystem is through a process called nitrogen fixation,” said Nina Wurzburger, an assistant professor in the Odum School of Ecology and the paper’s lead author. “Bacteria in the soil can pull nitrogen out of the atmosphere and convert it into a form available for themselves and for plants. They do this by creating an enzyme called nitrogenase.”

For years, it was assumed that the element phosphorus was the key ingredient bacteria in the soil needed to make this enzyme work. Now Wurzburger and her colleagues Jean Philippe Bellenger, Anne M.L. Kraepiel and Lars O. Hedin of Princeton University have found that another element, molybdenum, also is crucial.

“Our results were quite unexpected,” said Hedin, a professor of ecology and evolutionary biology. “We discovered that the trace element molybdenum often was the limiting nutrient, not phosphorus, as most theories would predict.”