In addition to herbs, some trees can act as weeds. In the southern Urals in Bashkortostan one of such weed trees is maple. It grows quickly, reproduces rapidly, and easily fills the land. So I have a question: is it possible to use a maple tree as a stock for fruit trees? Please, tell me which of the fruit trees are most similar to maple and can be successfully grafted on the root system of a maple tree? Are there some tables (directories) on mutual compatibility of trees in the sense of grafting? It would be interesting to experiment with grafting southern trees (coffee, cocoa, citrus, olives) on the root system of the northern trees. Does this raise their hardiness to cold? Do they start to drop their leaves in winter? It would also be very interesting to derive sorts of southern trees adapted for the northern climate.