Lake Michigan's Southern Shore: North Meets West Meets East

Dramatic stands of Eastern White Pine (Pinus Strobus) and Jack Pine (Pinus Banksiana) grow among Big Bluestem (Andropogon Gerardii), Eastern Prickly Pear (Opuntia Humifusa), as well as a variety of trees common to the eastern forests, notably oaks, hickories, ashes, willows, and more.  In a low, watery basin sits a spahgnum bog topped with boreal species, mere yards away from an open prairie, in turn yards away from an ash swamp, which sits behind cool depressions in sand dunes which give rise to great pines.  This meeting place is the world of the Indiana dunes, a natural point of junction that has also served as a great crossroads for people traveling between various parts of the continent.

Sand, wind, and glaciers are responsible for bringing together a diverse community of plant life that serves to defy definition for the area.  My first sign that I was in an altogether different place was the presence of so many White Pine that just popped up out of nowhere.

Both shots taken at Indiana Dunes State Park near the end of State Park rd.

Now normally when one comes across such stands so far south it is because park agencies would have planted them to add exotic interest to the environment, an attempt to create something of a "north woods mystique" to state and local campgrounds.  Pines might have existed here naturally at one point, but most that are seen south of the Great Lakes are nostalgic reminders of a timer before the great lumber pillage of the nineteenth century.  Here, however, they remain as relics of the huge stands that once helped to build Chicago.  They rise from the sands in scenes expected hundreds of miles to the north in northern Michigan and Ontario.  Travel only a few miles south, over ancient moraines left at the edge of long vanished ice sheets, and the sand is left behind to be overtaken by rich prairie soils and more temperate forests.  This is, after all, Indiana, a place one would hardly expect the north to thrive in.

Yet thrive it does.

But the north here is not alone.  The dunes are first stabilized by dune grasses...

...and more southerly trees like Eastern Cottonwoods (Populus Deltoides) and Eastern Redcedar (Juniperus Virginiana).

Eventually they are joined by trees found in more mature forests as richer soils are built up in the ever changing world of our eastern plant succession forests.  In some lower places, water stands for a significant portion of the year, and we have moist forests of ash trees, Swamp Cottonwoods (Populus Heterophylla), and other water tolerant trees.

Eventually the lake gets far enough away that its power over the shifting sands declines along with the sand itself.  Departure from the drainage basin of Lake Michigan marks an ecological departure into the Midwest, where a new struggle of plant succession takes place, waged not between sand and plant but fire and plant.  A mosaic of prairie, savanna, and forest stretches in all directions but north from atop the Valparaiso Moraine.  Looking north instead shows us what we have just seen, a meeting of north, east, and west.  These days humans mimic this corridor along our highways 20, 94, and various railroads.  Come by tomorrow for a look at the human presence in Indiana's "southern shores".