Mycorrhizal networks are underground networks of fungi that stretch over very large areas and interconnect with the root systems of many types of plants. It has been suggested that they are important in inter-plant communication via the so-called Wood Wide Web, although not all workers in this area are entirely convinced by this hypothesis. However, regardless of whether this hypothesis has a sound basis or not, there is now increasing evidence that underground fungal networks are an essential component in the global ecosystem, providing essential support to life on land and to biodiversity through their symbiotic relationships with plants. A further role of mycorrhizal networks which is especially important in the context of global warming is their contribution to carbon storage. In a recent report from scientists based in South Africa, the Netherlands, the USA, the UK and Belgium have reviewed the available data and have calculated that, at a conservative estimate, 36% of current CO2 emissions from fossil fuels is fixed by these networks.
According to statements made by the authors, soil ecosystems are being destroyed at an alarming rate through agriculture, development and other industry, but the wider impacts of disruption of soil communities are poorly understood and more needs to be done to protect these underground networks which are invisible to most people. The researchers are now investigating how long the carbon is stored by the fungi in the soil, since a major gap in our knowledge is the permanence of carbon within mycorrhizal structures.
For more information see: Heidi-Jayne Hawkins, H.-J., Cargill, R.I.M., Van Nuland, M.E., Hagen, S.C., Field, K.J., Sheldrake, M., Soudzilovskaia, N.A., Kiers, E.T. Current Biology 33 (11), R560-R573 (2023)
(2023) (open access)