I've been trying to collect wood from the trees. Apparently I cannot get wood drop with bare hand breaking it. Only with axe. Any fix?

It would be helpful to include what version of Forge and Dynamic Trees you are using. Also a screenshot or list of the mods you are using would be useful in tracking down the issue.

Also Look at #110 If you are using any of the following mods that might be the issue;
Better With Mods
PrimalCore
No Tree Punching

Other mods might be the cause if you don't have any of these, hence the question for all the mods you use.

This is the result of interaction with a mod designed to prevent a player from using hands to break a tree.