Pine forests are chock full of wild animals and plant life, but there's an invisible machine underground. Huge populations of fungi are churning away in the soil, decomposing organic matter and releasing carbon into the atmosphere.
Despite the vital role these fungi play in ecological systems, their identities have only now been revealed. A Stanford-led team of scientists has generated a genetic map of more than 10,000 species of fungi across North America. The work was published this week in the Proceedings of the National Academy of Sciences.
Fungi are much more important than most people realize, said Kabir Peay, an assistant professor of biology at Stanford and senior author on the new paper. "They are the primary decomposers in most of the planet's ecosystems," he said, "and if not for them, dead material would accumulate to the point where most other biological processes on Earth would grind to a halt."
Soil fungi can be divided into two primary groups. The saprotrophs live in the top layer of soil, digesting dead matter, breaking up molecules into individual components converting proteins into amino acids and starches to simple sugars, and freeing up elements such as nitrogen that plants rely on for growth.
The other group, mycorrhizal fungi, have an even closer bond with plants, living among their roots and converting older forms of organic matter into nitrogen and phosphorus for the plants. In return, the plants feed these fungi a steady stream of sugars they obtain from photosynthesis.
The soil stores three to four times as much carbon as the atmosphere, and all this microorganism activity also releases some of that carbon into the air, to a tune of 10 times the amount of carbon into the atmosphere as humans release through emissions.
"It's a huge flux of carbon into the atmosphere, and fungi are the engines," said Jennifer Talbot, a postdoctoral research fellow in Peay's lab and first aut
|Contact: Bjorn Carey, Stanford News Service|