Are West Michigan’s Sand Dunes Disappearing?
Michigan is home to a large collection of "living" sand dunes, which means they're constantly moving and eroding. As we Michiganders know, you can visit the same beach twice and get a different view each time! However, in recent years researchers have noticed Michigan's sand dunes are increasingly covered by vegetation such as plants and trees.
True, the dunes need vegetation to keep them from blowing away completely, but what's the cause of this new vegetation and should we be concerned? Two dune researchers, Kevin McKeehan and Alan Arbogast, are trying to get at the "root" of the cause of all this vegetation. They say they have some theories, but are left with more questions than answers.
Using repeat photography, a process in which you essentially compare photos side-by-side, McKeehan and Arbogast are noticing extreme changes along Michigan's east and west coast sand dunes. Each image they compared, some as recent as 13 years ago all the way up to 100 years ago, all had the same thing in common: less sand, more vegetation.
Why the Change?
Some speculate increased rainfall in recent years has created the perfect environment for vegetation to take hold and grow in the sand. Others say increased carbon dioxide in the air offers more nutrients for plants to flourish. Perhaps it's a sign of more invasive plant species? There has also been a measurable decrease in wind which could mean the dunes are moving less. McKeehan told Detroit's Fox 2, "there are potential culprits, but no smoking gun."
Will the Dunes Disappear?
Using carbon dating, McKeehan and Arbogast have narrowed down the creation of Michigan's sand dunes to about 5,000 years ago. Through this process they were able to determine that the dunes grew in stages. Arbogast says, "Not all of this grew at once. It grew, then stopped, then grew, then stopped again," adding, "it stopped long enough for a forest to live there, then it grew again."
Perhaps this is just the next life cycle for our dunes. This period of inactivity may eventually be followed by another period of active change, and so on and so forth. This is a great reminder to not take all the things that make Pure Michigan so special for granted, including the fact that we have, "the largest dune system in the world associated with a freshwater lake."
If you'd like to see how Michigan's sand dunes have changed over time, check out McKeehan and Arbogast's extensive "Sands of Time" project here.