Mycorrhizal fungi and soil carbon storage

[5] Recent research has shown that mycorrhizal fungi hold 50 to 70 percent of the total carbon stored in leaf litter and soil on forested islands in Sweden.

[8] Outlined below are the leading lines of evidence for how different aspects of mycorrhizal fungi may alter soil carbon decomposition and storage.

[10] However, a recent set of experiments demonstrates the presence of arbuscular mycorrhizal fungi results in net losses of soil carbon,[11] calling into question the role of glomalin produced by arbuscular mycorrhizal fungi leading to increased soil carbon storage.

[12] Proteomic work has revealed that most of the proteins isolated in the glomalin extraction are not of mycorrhizal origin, and therefore the contribution of this molecule to soil C storage has likely been overestimated.

Arbuscular mycorrhizal fungi have been shown to increase soil carbon decomposition in nutrient rich patches.

[29] The mechanism presented is that ectomycorrhizal fungi can compete with free-living decomposers for nutrients, and thereby limit the rate of total decomposition.

Since then there have been several other reports of ectomycorrhizal fungi reducing activity and decomposition rates of free-living decomposers and thereby increasing soil carbon storage.

[30][31][32] A theoretical ecosystem model recently demonstrated that greater access to organic nitrogen by mycorrhizal fungi should slow decomposition of soil carbon by free-living decomposers by inducing nutrient limitation.