Mother Trees
Yes, "mother trees" can recognize their own seedlings and support their growth by sending them extra nutrients through the mycorrhizal network.
See You Later, Sucker
Trees are smart and are constantly participating in the process of "self-pruning" in which a tree can sacrifice a limb to prevent the spread of a disease or to provide resources to a healthier part of the tree.
Interconnected Trees
Trees in a forest can sense and respond to each other through the mycorrhizal network and the exchange of chemical signals.