Nitrogen release by decomposing plants is surprisingly similar across the planet and could help shed light on the evolution of climate change, researchers said in a study released Friday. Dozens of researchers worked for 10 years in 27 sites, from Arctic tundra to the tropical forests of North and Central America, in one of the largest studies ever done on nitrogen release during plant decomposition published in the journal Science.
"The availability of nitrogen is one of the key factors limiting vegetation growth around the world, but its release from plant litter can be very slow," said Mark Harmon, a professor of forest science at Oregon State University.
"For the first time, we studied this process at enough sites and over a long enough time period to really understand what's happening."
The results could help measure vegetation growth, carbon release and sequestration, as well as the potential impacts of climate change.
Researchers said they were surprised by the fact that the essential pattern of nitrogen release is nearly the same wherever it occurs, and depends mainly on the initial concentration of nitrogen present in the decaying plant material.
It has very little to do with location, soil types, microbes present, or other factors, the research found.
While the pace of the process is affected by climate — temperature and precipitation — the overall pattern, or "trajectory" of nitrogen release remains much the same regardless of the site, researchers found.
Plant growth is a main factor that affects the input or removal of carbon from the atmosphere — an issue of growing importance during an era of global warming.
Plant decomposition releases more carbon each year than all of the fossil fuel combustion produced by humans, the researchers stressed in their study.
"If we hope to better predict carbon dynamics, climate change and other issues, we first must understand these basic ecological processes," Harmon said.
Source: Agence France-Presse
