Winter 1999

"Floral melting pot" includes marram grass, arctic bearberry, cottonwood and seaside spurge

Porter County, Indiana

Carl Sandburg once said, "The dunes are to the Midwest what the Grand Canyon is to ArizonaŠThey constitute a signature of time and eternity." Wrought by the incessant work of wave and wind over the millennia, the Indiana Dunes offer a trip forward or backward through geologic time.

Here Dr. Henry Chandler Cowles, the University of Chicago botanist known by many as the father of North American ecology, conducted his landmark studies in plant ecology at the turn of the century. Here he discovered the orderly and predictable sequence of change in plant communities at a given location — what he called 'succession' — as landscape and climate conditions change over time. No wonder Dr. Cowles dubbed this living botanical laboratory a "floral melting pot."

Indiana Dunes rolls over thousands of acres of lakeshore wilderness. Visitors can observe the diversity of flora and fauna that flourish in its many habitats. Starting at the lakeshore, you'll see the Beach Association, or first plant colonizers of the area, consisting of flora like seaside spurge and sea rocket. Strolling along from the lake towards the interior, you'll encounter the Foredune Association: dune-builder plants like marram grass, sand reed grass, sand cherry, and willow shrub. Next comes the Cottonwood Association, young dune species like cottonwood, milkweed, and hoary puccoon. The Pine Dune Association, consists of, among others, arctic bearberry, jack pine, white pine, juniper, and cedar. Continuing on your walk through time you'll encounter the Black Oak Association where oak, hickory, ash, maple, and other plants thrive that are not tolerant to the earlier shifting topography, extremes of climate, or poor soil conditions. Lastly, in a few areas that were protected from fire, the Beech Maple Association can be found further inland.

Also here you can observe blowouts, huge amphitheater bowls of scoured-out areas hidden among the high dunes. Or look for the tree graveyards: standing dead groves of relic trees buried by the advancing dunes, then disinterred by their retreat. One unusual plant for this region is the prickly-pear cactus, a plant more used to the desert regions of the Southwest, but also found here in the sandy wilderness of the dunes. Jack pines are isolated relics of earlier arctic conditions, when glaciers were still active in the area. Normally found only 60 miles north of the dunes, this tree species migrated south when the climate here resembled that of more northern regions. When the climate warmed, the jack pines managed to survive in the dunes' exposed conditions.

The Dunes are part National Lakeshore and part State Park. At the latter, 10 trails totaling 16.5 miles pass over nearly 200-foot tall drifting mounds of sand, across three miles of lakeshore beachfront, along marshes, and through 1,800 acres of woods. Winter visitors can cross-country ski or snowshoe along the 9.2-mile Calumet Trail. It traverses varied and unusual topography, from interior blowouts to exposed foredunes. Indiana Dunes National Lakeshore surrounds the state park on three sides. The park is open from 7 a.m. to 11 p.m. every day of the year. For more information, call (219) 926-1952.

As you walk, listen for the singing of the sands, a high, clear, musical ringing tone, similar to that of a tuning fork, which you will create just by walking on the wet sand and producing friction. This harmonizes with the quartz crystals, moisture and pressure; you will, in effect, be strumming the earth with your toes.

— Eugene Bender