Andy, aspen is a different animal. If you want to maintain any future aspen stands you can't just thin it. It can't regenerate that way. Apen needs to be clearcut to regenerate. When I say clearcut I do not necesarily mean what you think. A clearcut might only be 1/2 an acre. You have to open up the forestfloor.
There are lots of resources available to the Michigan landowner to help educate them on selecting a proffessional to harvest your timber.
Start with The Timber Buyers Network. Use that and here to answer your questions.
www.timberbuyer.netGo to
www.mfra.org and order thier free brochures.
You can go to
www.timbermen.org to ask specific questions about michigan loggers or other forest products companies. They can be a wealth of knowledge.
You definitly need to get a forester involved to help get you where you want to be.
Aspen logs may be purchased by the cord or by the thousand board foot. Most sawlogs must be a minimum of 10 inches at the small end to be concidered a log. A 12 inch tree is only going to give you one log. Length depends on the buyer and his current markets.
The remainder of the tree that is to small for logs can be sold as pulp or chips. Pulp may be bought by the cord, but as a rule now days it is bought by the ton as are the chips.