By Sid Perkins
Laboratory tests have revealed for the first time that certain types of common fungi can produce ozone-destroying methyl halide gases. The origin of substantial fractions of these gases in the atmosphere has eluded scientists.
Ectomycorrhizal fungi–literally, fungi that envelop roots–form symbiotic relationships with trees. The fungus pulls nitrogen and phosphorus from the soil and then provides some of those nutrients to its arboreal partner. In return, the microbes receive carbohydrates produced by the tree (SN: 6/16/01, p. 372: New test traces underground forest carbon). These fungi are often, by weight, the most prevalent group of microbes in the soil of temperate forests, says Kathleen K. Treseder, a biogeochemist at the University of Pennsylvania in Philadelphia.