Bill Cook

Michigan forests are not as “pristine” as some in the media would have us believe. Nearly all Lake States forests are the product of severe human disturbance and all the forests are facing significant threats.

I stood quietly overlooking the Maggia River valley in southern Switzerland contemplating the differences between the forest around me the forests of home. I looked downslope, across a stone terrace that was once a piece of a vineyard, and marveled at the leaf pattern of some young chestnut trees where grapes no longer grow.

The long serrated leaves, forming a unique pattern of distribution, were once one of the most common sights in eastern North America. No more. Not for over a century. Our New World chestnut has been all but eliminated from the forest by a blight imported from Asia. That was a category five disturbance.

American chestnut had been the most ubiquitous tree among the eastern hardwoods. It made excellent timber and the nuts were good food. Nobody alive remembers the expansive American chestnut forests. Gone like the passenger pigeon.

As I look around where I’m standing among the shoulders of the Alps, I see the spiny fruits from last year. They remind me of sea urchins. I think of the wood in Conestoga wagons, named after the Pennsylvania County where German immigrants designed the vehicle.

As I gaze across the expansive valley, framed by rock cliffs carved by glacial ice, I am reminded that the physical geography of the Alps greatly reduced tree diversity on the north side, as the forests were smashed-up against the high peaks. There are more tree species on the south side.

I also think about tree species losses in the Lake States. Chestnut only reached a small portion of what is now Michigan. But across its larger range it’s nearly absent. My thought process extends to American elm and red elm. They, too, have almost dropped out of the picture, but not as substantially as chestnut.

More recently, most of us are all too familiar with the losses of white ash, black ash, and green ash from the emerald ash borer. I have a small but growing collection of ash lumber. I’m saving it for my grandchildren, so my son can make them furniture from a nearly extinct set of species.

Similarly, beech bark disease has removed the beech component from our forests. Beech had an interesting distribution in Michigan, not daring to cross west of a line that ran roughly from Iron Mountain to Marquette. Black bears are poster children among those wildlife that will lament the loss of beech. The bears will be just fine but they’ve lost a favorite food. And we have lost a marvelous species.

We hear more and more about oak wilt, which has been documented since the 1940s. The disease has spread to many oak forests, especially those oaks in the “red oak group” of species. One can argue that many of our oak forests are largely products of human history and not “naturally” occurring. However, to the visitor or resident, that matters little as they watch the oak forest brown and die.

Then also, we’ve lost butternut and bitternut. They were always less common. Now, they’re almost non-existent. Our hemlocks have been hit, now, by a woolly adelgid, which is a small sap-sucking insect. Much hemlock has been killed in the eastern states. Most of Michigan’s hemlock grows in the U.P. and has yet to see the adelgid that has popped-up in parts of the Lower Peninsula along Lake Michigan.

The gradual, but increasing, loss of tree species concerns some folks. Others barely notice. Trees are just trees. However, the “biggie” to watch for is the Asian long horned-beetle or ALB.

The ALB has a long host list but its favorites are maples. Try to imagine the Lake States without maples! The ALB has been eradicated in several places. The closest active infestation is in southern Ohio.

Europe has only a fraction of the number of tree species found in North America. By and large, their forests are less diverse and human populations significantly higher. As I stand on my mountainside overlooking chestnut crowns, I wonder how North America will fare with massive attrition of forest species. Europe seems to be doing alright. Yet, I’m saddened that my grandchildren will not be able to enjoy the same sort of forests from when I was a kid.

I suppose time will tell.