Dryland soils store carbon up to thousands of years, much longer than expected

Drylands cover roughly 40% of Earth’s land surface and play a major role in the global land-atmosphere carbon exchange. Most carbon in dryland ecosystems is stored in soils, but little is known about its stability and persistence upon climate and vegetation change. Researchers at the Max Planck Institute for Biogeochemistry now used radiocarbon to show that organic carbon in dryland topsoils is much older than previously estimated, averaging about 2,000 years. However, when dry soils are wetted, even old carbon is decomposed and respired by microbes. The results can improve predictions of soil organic carbon dynamics in global drylands under rapid climate and land use changes.
Quelle: IDW