Is this a prank, like crop circles?

I think mollweide has it- it is a planting pattern that is designed to support the Kirtland's Warbler. My family has a cabin a few miles from this site. as you can see in this http://books.google.com/books?id=cayTRiPBpsoC&lpg=PA169&ots=4IOsKdpryE&dq=tree%20planting%20opposing%20wave%20pattern&pg=PA170#v=onepage&q=tree%20planting%20opposing%20wave%20pattern&f=false, This is an example of what is called an "opposing wave pattern" of planting, and is important for creating the mosaic and edge conditions one normally would find in a Jack Pine forest that was under a natural fire regime.

Those aren't crop circles. What you are seeing is the result of http://www.sciencedirect.com/science/article/pii/S0378112710000472.

This area is the summer home to Kirtland's warbler, an endangered songbird that requires a very specific type of habitat for breeding and foraging. This habitat of young jack pines stands of a certain minimum size needs to be maintained by harvesting and fire. There's an active management program to create this type of habitat on the Upper Peninsula. This pattern could be related to that program and species. Otherwise, it could be intensive harvesting and/or planting done in a pattern to promote habitat for other species, most likely game species. Deer and quail come to mind as species that would benefit from open spaces interspersed among a forest matrix. In a few places you can see the trees were planted in that pattern, in wavy rows. In other places, it looks like the entire area was planted with trees and then the pattern was cut out of the trees.

I think the explanation http://www.cropsreview.com/planting-patterns.html explains it. Some way of spacing two crops that need different separation, and in this case a marked visual contrast between the rows and the gaps.

In Jimbob's link they look like Christmas trees, in which case it is important to preserve the limbs and needles as much as possible. Doing that in a crowded forest is difficult, so those little patches of open space probably spell the difference between a profit or not. They can get the limbs contained all at once and then carry the trees out safely, concentrating on the trees that are ready to be harvested. Given how sparse the area is, and the number of trees, I suspect it's an industrial operation.

It's not intensive harvesting. If you zoom in on one of the lighter areas, you can see that the trees were planted in that pattern; i.e., the spaces aren't due to harvesting.

More on the history of the quincunx planting plan- which this seems to be- is inhttp://gardenhistorygirl.blogspot.com/2009/01/quincunx.html

Unexpectedly close to some 'home turf' for me. What's the double lines adjacent to the roads there? Looks like a freeway, but I-75 is a ways over.

I think this is http://www.fao.org/docrep/x5367e/x5367e02.htm which is used to increase biodiversity when reestablishing a forest.