Rotting leaves are contributing to global warming


In Michigan, Michigan State University scientists have pinpointed a new source of nitrous oxide, a greenhouse gas that’s more potent than carbon dioxide – tiny bits of decomposing leaves in soil.

“Most nitrous oxide is produced within teaspoon-sized volumes of soil, and these so-called hot spots can emit a lot of nitrous oxide quickly,” said Sasha Kravchenko, MSU plant, soil and microbial scientist and lead author of the study. “We found that hotspot emissions happen only when large soil pores are present,” Kravchenko said. “The leaf particles act as tiny sponges in soil, soaking up water from large pores to create a micro-habitat perfect for the bacteria that produce nitrous oxide.”

Nitrous oxide’s global warming potential is 300 times greater than carbon dioxide and emissions are largely driven by agricultural practices. This new discovery could help refine nitrous oxide emission predictions as well as guide future agriculture and soil management practices.