Underground Mycology: The Relation Between Fungi, Soil and Tree

Fungi interact directly with trees as biotrophs (obtaining nutrients from living cells/tissues) either parasites or mutualistic mycorrhizas, and as necrotrophs (obtaining nutrition from cells/tissues that they kill). Mycorrhizas are crucial to the health of the vast majority of plants in nature, supplying them with water and mineral nutrients, and protecting against root pathogens. Fungi affect trees indirectly as saprotrophs, by decomposing dead organic matter and releasing the nutrients that were locked up therein. The relations between fungi, soil and tree are complex since fungi also interact with each other, with other microorganisms and with soil invertebrates affecting mycelial growth and functioning. With changing climate the outcome of these interactions is likely to differ, and hence the interaction between fungi and trees will also differ.