A tree is not just a tree, but an ecosystem. James Merryweather discusses the definition of symbiosis and delves into the symbiotic relationship between mycorrhizal fungi and trees.
This piece has emerged from ideas inspired by David Wilkinson’s thought-provoking contribution ‘What is a lichen? Changing ideas on the lichen symbiosis’ to the June 2018 issue of British Wildlife (BW 29: 351–357), along with knowledge gained through ecological research and 19 years of post-retirement observation, reading, teaching and thinking. I extrapolate Wilkinson’s ideas, applying them to what I consider to be lichen-like symbioses of other organisms, using the tree as a model, in the hope that this will promote a better understanding of symbiosis.