Systems VIII - As above, so below

There is whole network of tree communication underground through their root systems, affectionately called the wood wide web. Fungal strands called micorrhiza in the soil connect the roots together and the largest networks can extend out for several miles. The tree and the micorhizza funghi are a symbiotic system, mutually working together to exchange nutrients. The fungi need carbon from the tree and the tree needs the nutrients fungi can absorb that their roots can't access. The roots and the fungi link trees together into a huge resource sharing community, passing nutrients to trees in the system that need them.