Frequent burning over decades reduces the amount of carbon and nitrogen stored in soils of savanna grasslands and broadleaf forests, in part because reduced plant growth means less carbon being drawn out of the atmosphere and stored in plant matter. These findings by a Stanford-led team are important for worldwide understanding of fire impacts on the carbon cycle and for modeling the future of global carbon and climate change.
The results, published Dec. 11 in the journal Nature, offer a new perspective on the impact of fire on soil fertility.
“Almost all the synthesis studies done to date conclude that fire has relatively little effect on soils, but in large part, researchers focused on a single fire event,” said Adam Pellegrini, a post-doctoral scholar at Stanford’s School of Earth, Energy & Environmental Sciences and lead author on the study.
Instead, this study examined soil carbon and fertility in different ecosystems over 65 years.