When soil in these forests is warmed, a UC Irvine study found, fungi that feed on dead plant material dry out and produce significantly less climate-warming carbon dioxide than fungi in cooler, wetter soil. This surprised scientists who had expected warmer soil to emit larger amounts of carbon dioxide because extreme cold is believed to slow the process by which fungi convert soil carbon into carbon dioxide.
Knowing how forests cycle carbon is crucial to accurately predicting global climate warming, which in turn guides public policy to curb greenhouse gas emissions. This is especially important in northern forests, which contain an estimated 30 percent of the Earth’s soil carbon, equivalent to the amount of atmospheric carbon.
“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 & evolutionary biology assistant professor and lead author of the study. “The Earth’s natural processes could give us some time to implement responsible policies to counteract warming globally.”
…“It’s fortuitous for humans that the fungi are negatively affected by this warming,” said Treseder, ecology & 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.”….
2 comments:
It's a little more complicated than this article suggests. If these fungi form mycorrhizal relationships with the spruce trees, then the trees could become less efficient at fixing carbon due to reduced nutrient availability. Mycorrhizal relationships are mutualisms formed between most land plants and many species of fungi. Generally speaking, the fungus provides the plant with greater access to nutrients in the soil, while the plant provides the fungus with sugars. If fungal respiration (the conversion of carbon soil to carbon dioxide) is reduced, then the fungi's ability to perform this service to the spruce trees could be reduced, which means the trees would not be as healthy. Ultimately, this means that the benefit of a lower rate of conversion of carbon soil to carbon dioxide would be reduced because the trees in the same area would not be fixing as much carbon (converting carbon dioxide into plant biomass).
This is very helpful -- great to have s little more context about these processes.
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