A tree gives glory to God by being a tree. For in being what God means it to be, it is obeying Him. It "consents," so to speak, to His creative love. It is expressing an idea which is in God and which is not distinct from the essence of God and therefore a tree imitates God by being a tree.
The more a tree is like itself, the more it is like Him. If it tried to be like something else which it was never intended to be, it would be less like God and therefore it would give Him less glory.
No two created beings are exactly alike. An their individuality is no imperfection. On the contrary, the perfection of each created thing is not merely in its conformity to an abstract type but in its own individual identity with itself. This particular tree will give glory to God by spreading out its roots in the earth and raising its branches into the air and the light in a way that no other tree before or after it ever did or will do.
Thomas Merton, New Seeds of Contemplation