by Annie-Rose Strasser / Climate Progress
A mushroom from an ectomycorrhizal fungus. Credit: Creative Commons
You might be a person who loves to eat a portabello sandwich or one who turns your nose at the sight of a salad bar button mushroom, but no matter your feelings on the gustatory nature of fungal fruit, you’ve got to respect fungi for one thing: Helping to fight climate change in a small but mighty way.
In a new study, scientists found that two certain types of fungi, known as ecto- and ericoid mycorrhizal (EEM) fungi, have the ability to drastically alter how much carbon gets sunk into soil or released into the air by as much as 70 percent. Since soil holds massive amounts of carbon — more than air and plants combined — this has a huge impact on the climate.
Here’s how it works: Nitrogen in soil is what feeds the little microorganisms that break down dead matter and release its carbon back into the atmosphere. But the EEM fungi (not to be confused with a mushroom — the mushroom is the fruit of a fungus) that live in the roots of plants steal some of that nitrogen out of the soil and turn it into nutrients for plants. In the process of stealing it, they’re ridding the soil of nitrogen. So when that plant eventually dies and returns to the soil to be broken down, in places where EEM fungi are present, it’s less quickly turned into carbon that goes back into the atmosphere.
This happens anywhere EEM fungi live — no matter the makeup of the soil, or what the climate of the location is.
The process might sound technical and small-scale, but its implications are significant. No scientist studying carbon cycles has factored in the high carbon capture rates of EEM fungi before. And though it isn’t the most common type of fungus in soil — another type makes up 85 percent of soil — it could still change climate models.
“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 how the two groups interact. We need to think of these systems holistically,” Colin Averill, the lead author on the study, said.
The relationship between fungi and climate has always been complex. Some mushrooms are thriving thanks to a changing climate — something scientists still aren’t sure is a bad or good thing. Others, like the EEM fungi, are doing their part to help climate change. In April of 2013, scientists first discovered that mushrooms could be major carbon sinks, sequestering between 40 and 70 percent of the carbon in soil, and burying that carbon deeper down in the soil than if it were coming from the decomposing leaves and needles on a forest floor.
