The ability of soil to store carbon will weaken as carbon dioxide levels in the atmosphere rise to the amounts predicted for the end of this century, suggests a report in Nature this week.
Richard A. Gill of Duke University, Durham, North Carolina, and colleagues present evidence from field experiments on a grassland ecosystem. They show that soil's traditional role as a carbon sink could now be at an important threshold.
Soils may have played a role in taking up carbon dioxide since the last ice age, but their ability to continue to do so may be limited by nutrient availability, warn the researchers.
Source: Nature 417, 279 (2002)
Link to paper by Richard A. Gill et al
Photo credit: David J. Moorhead, The University of Georgia, Image 0005012. ForestryImages.org.http://www.forestryimages.org/. May 16, 2002.