Being a compassionate person I'd recommend that you talk with him. Share with him that it appears that a wheelbarrow was rolled up your drive way and to your woodpile. Let him know that you're happy to lend a helping hand if one of the neighbors is in need but that you must politely insist that they let you know that they're doing so.
If he doesn't own up to it, then ask him to help you keep an eye on things, that the last thing you want to do is to call the police and report that you've been robbed of your personal property.
If he does own up to it, re-affirm that you understand that folks sometimes fall on hard times, but that in the future he must let you know that he needs some wood.