My son loves trees.
My discussion with him this morning: A tree does not seem to have a blob of brain similar to humans or animals, instead it seems to have a distributed mechanism of perception, analysis and decision making.
I would love to give 10 years of my life to understand the mechanisms by which a tree thinks.
This would be the question of “How”.
Only after that, we can ask “What does a tree think?”, a question for which arts and literature may have better answers.
What about, “Why does a tree think?”, a much harder question with deep philosophical underpinnings.

For humans and animals:
We barely understand the how.
We hardly understand the what.
We don’t understand the why.

I love trees, like my son, I loved climbing on top when I was a child, sitting and pondering under them when I was a man. Hopefully someday I will be buried under one.