Global warming is expected to hit northern latitudes hardest, raising temperatures between 5 and 7 degrees Celsius by the year 2100. But now scientists experimenting with life under dryer conditions have made a stunning discovery about Northern forests that could be key in the fight against global warming itself.
The scientists found out that mushrooms growing in the warmer, dry spruce forests of Alaska, Canada, and Scandinavia produce less climate-warming carbon dioxide than fungi in cooler, wetter soil. That’s baffling. Normally, you’d expect warmer soil to increase carbon emitted. You’d expect extreme cold to slow down the process by which fungi plants convert soil carbon into carbon dioxide. Turns out the opposite is the case.
“We don’t get a vicious cycle of warming in dry, boreal forests. Instead, we get the reverse, where warming actually prevents further warming from occurring,” said Steven Allison, ecology and evolutionary biology assistant professor and lead author of the study.
Allison wrote up his team's findings in an article in Global Change Biology.
“The Earth’s natural processes could give us some time to implement responsible policies to counteract warming globally,” said Allison, who is attached to the University of California at Irvine. A precise idea of how forests cycle carbon is key to get a precise picture on future global climate warming, not least because forest soil contains about the equivalent to the amount of atmospheric carbon. And northern forests contain around 30 percent of the planet’s soil carbon which is mostly coming from dead grasses, trees and shrubs. The mushrooms or fungi plants that grow in these forests feed of the carbon and convert it into carbon dioxide.
The study, which was supported by the National Science Foundation, the U.S. Department of Energy, and a NOAA Climate and Global Change Postdoctoral Fellowship, researched what happens to carbon dioxide levels when boreal forest soil not containing permafrost gets warmed.
Together with his colleague Kathleen Treseder, Allison used greenhouses to raise air temperature by about 5 degrees Celsius, and soil temperature by about 1 degree. They then took measurements and found soil in warmed greenhouses produced about half as much carbon dioxide as soil in cooler temperatures. The team also discovered that about half as much active fungi were present in the greenhouse mushrooms compared with samples from ordinary plots. Alison and Treseder concluded that when fungi dry out, they either die or become inactive and stop producing carbon dioxide.
“It’s fortuitous for humans that the fungi are negatively affected by this warming,” said Treseder, ecology and evolutionary biology associate professor. “It’s not so great for the fungi, but might help offset a little bit of the carbon dioxide we are putting directly into the atmosphere by burning fossil fuels.”