Fungi Have Major Impact on Carbon in the Atmosphere: Implications for Climate Models

Fungi may have more of an impact on our atmosphere than you might think. Scientists have found that microscopic fungi that live in plants' roots play a major role in the storage and release of carbon from the soil into the atmosphere. The findings could have major implications for global climate models.

"Natural fluxes of carbon between the land and atmosphere are enormous and play a crucial role in regulating the concentration of carbon dioxide in the atmosphere and, in turn, Earth's climate," said Colin Averill, one of the researchers, in a news release. "This analysis clearly establishes that the different types of symbiotic fungi that colonize plant roots exert major control on the global carbon cycle, which has not be fully appreciated or demonstrated until now."

Plants usually partner with two major types of symbiotic fungi--ecto- and ericoid mycorrhizal (EEM) fungi and arbuscular mycorrhizal (AM) fungi. EEM fungi produce nitrogen-degrading enzymes, which allow them to extract more nitrogen from the soil than the AM fungi.

In order to learn a bit more about fungi's impact on the atmosphere, the researchers examined data from across the globe. In the end, they found that when plants partner with EEM fungi, the soil contains 70 percent more carbon per unit of nitrogen than in locales where AM fungi are the norm. In fact, the EEM fungi allow the plants to compete with the microbes for available nitrogen, thus reducing the amount of decomposition and lowering the amount of carbon released back into the atmosphere.

Since soil contains more carbon than both the atmosphere and vegetation combined, predictions about future climate depend on a solid understanding of how carbon cycles between land and air. These new findings could have major implications for climate models that take into account the cycle of carbon in the atmosphere.

"This study is showing that trees and decomposers are really connected via these mycorrhizal fungi, and you can't make accurate predictions about future carbon cycling without thinking about future carbon cycling without thinking about how the two groups interact," said Averill in a news release. "We need to think of these systems holistically."

The findings are crucial for creating better climate models. This, in turn, could impact predictions of warming in the future.

The findings are published in the journal Nature.