Only if they are different species. Root fusion is a thing and it can help lift young trees up to the canopy by slipping them extra sugars through the root system.

Two vivid demonstrations of this are albino trees that grow despite having no chlorophyll of their own, and living tree stumps - the stump scars over, yet never grows branches of its own, because it is fused to a sibling nearby. I’ve seen pictures of both, but have only seen the latter in person.