One thing is that mother trees suckle their children, they feed the young tree just enough sugars produced by its own photosynthesis to keep it from dying. Trees in a forest of the same species are connected by the roots, which grow together like a network. Their root tips have highly sensitive brain-like structures that can distinguish whether the root that it encounters in the soil is its own root, the root of another species, or the roots of its own species. If it encounters its own kind, I don’t know if scientists yet know how this happens, but we have measured with radioactive-marked sugar molecules that there is a flow from healthy trees to sick trees so that they will have an equal measure of food and energy available. […] We have this essentially arbitrary caste system for living beings. We say plants are the lowest caste, the pariahs because they don’t have brains, they don’t move, they don’t have big brown eyes. Flies and insects have eyes, so they are a bit higher, but not so high as monkeys and apes and so on. I want to remove trees from this caste system. This hierarchical ranking of living beings is totally unscientific. Plants process information just as animals do, but for the most part they do this much more slowly. Is life in the slow lane worth less than life on the fast track?
Interview with Peter Wohlleben (Yale Environment360)