Legal Question in Civil Litigation in Michigan

I'm not sure what you mean by "it looks like" the equipment is abandoned after 30 days. Are you referring to a law? In your letters, did you mention his removal of the equipment, or focus only on the contract and money that is owed? If you haven't already, give him formal notice that the equipment/property that is on your property will be sold in 30 days if it is not removed, or other arrangements have not been made. If he does not pay you the money that is owed, you would need to pursue this in court to enforce the contract terms. By his actions of removing the trees with your permission, clearly there was some agreement in place, which he has breached by failing to pay. Verbal agreements are enforceable in court, it is just harder because it is based on each person's word, therefore leaving the court to determine the credibility of each person. Offhand, and without knowing more details, it's clear to me that there was an agreement and that he does owe you money, provided that he can't prove he paid you already, and there is proof that he actually removed some trees.

Take pictures immediately of the area where he removed the trees and of the equipment that is currently on your property, and ensure the photos are dated. Confirm any conversations in writing and keep notes of anything that comes to mind.

You may need to retain a lawyer to first send him a "demand" letter re: the equipment and payment and, if that proves futile, to pursue a civil action for your monetary damages.