I made a half-day pilgrimage to a special place while heading back home after an agriculture conference in Iowa and stopped to hike and honor the memory of Henry Chandler Cowles. Known as the Father of Ecology in American natural sciences, it was Henry's intense study of the southern shore of Lake Michigan that transformed how we think about plants and plant communities as highly adaptable and responsive to fast changing environments. He is known as the Father of American Ecology and his work as a ecologist/botanist teacher influenced generations of future conservationists, plant ecologists, and landscape ecologists.
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| Driving winds out of the north raise angry waves and push tons of sand landward |
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| Marram grass anchors sand on the backshore. |
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| Marram grass, Ammophila brevilugilata |
Cowles traveled thousands of times between the University of Chicago where he taught botany to these windswept southern shores to study the effects of wind on moving sand dunes and how plant communities adapted to harsh, always-in-motion conditions. He studied the way dunes traveled inland and how plant debris caught up in the sands created seed beds and top soils for different plant communities. He focused on the concepts of plant succession. Starting with Marram Grass he was able to create living laboratories of ecological relationships of plant life to abiotic factors such as water table, shifting sands, and climate. These studies attracted students and the public alike - everyone taking an intense interest in the amazing variety of plant life to be found in the Indiana Dunes region of the southern lake shore.
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| Transitory dune scrub pine and cottonwood forest |
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| Scrub forest gives way to more stabilizing mature forest. |
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| Black Oak savanna |
Cowles' ideas include the concept of climax communities, in this case mature Black Oak forest that described a very stable environment. The only situation in which a climax forest would change, he argued, was if a critical disruption like flood, fire, or removal were to occur. He traveled all over the country to compare dune ecosystems, from Great Lake shores to New England beaches, to interior dune lands of Montana, Illinois, and Tennessee. His concepts of succession and climax sparked a scientific tidal wave of interest the new field of ecology. His botany classes filled to capacity (for thirty years!) and he was ever on the move - like his beloved dunes - traveling in summers to host teams of European ecologists to see the ecosystems of the U.S.
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| Inter-dune landscapes include fens, vernal ponds, and marshes. Note the beaver lodge (center left) |
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| Understory plants form diverse communities depending on aspect, slope, moisture, and soil. |
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| Woodland Sunflower |
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| Red Raspberry Slime Mold |
From all of his travels and intense study of how plant communities adapt to changing conditions, groups of scientists formed around the ideas of plant evolution, ecosystems, and habitats. These groups coalesced as the Ecological Society of America (1913) which is still an important scientific professional group today. ESA also gave rise to several sibling groups including the Nature Conservancy and regional conservation organizations. Regional groups around the Great Lakes region, especially for the southern shore of Lake Michigan, pulled together to fight for the conservation of these important biological sites. These landscapes were Cowles' first laboratories and they are conserved by a number of public lands agencies including Indiana State Parks and the National Park Service.
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| Butterfly Milkweed |
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Prairie Phlox
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| Common St. Johnswort |
I walked the 4.5 mile trail that formed a figure-8 through the foreshore and back dune area and thought about how Cowles' idea have survived over the last century. Like the ever-changing communities he studied even his ideas that were so popular as to start a movement in ecological science have adapted. We no longer think of climax forests as the stopping point of plant community development where "mature" forests mean the end of community change. Now we understand that mature and old growth forest continue to develop and adapt as environmental factors punctuate and shift how communities respond to pest invasions, climate change, air quality, or fire. There is no real climax stage after all, but I think Henry would be perfectly fine with this idea since he was, after all, testing our capacity to accept the concepts of change and evolution in the natural world.
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| American Toad |
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| A very steep climb! |
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| Dedicated to the ecological work of Henry Chandler Cowles |
I've made a promise to come back. A few hours of hiking and botanizing wasn't enough to really absorb the rich biological treasure that this area contains. The place intrigues me for other reasons, too, like how residential and industrial areas threaten or compliment what is saved. How are human communities working together to protect the integrity of the Indiana Dunes? (or not) What are the biggest threats to conserving a changing landscape of wind, sand, and forest? But for now, wandering the trails of the Cowles Bog Area, I thanked him for inventing field trips and believing that women could be a-m-a-z-i-n-g ecologists - his own important contribution to the idea that succession happens in science teaching, too.
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| Dr. Cowles and his students, University of Chicago (early 1900s) NPS |
To those wanting to hike this area, just know that hiking on sand or sandy trails is very different than woodland trails. Even just a few miles out-and-back on this trail involved some very steep climbing on shifting surfaces and what might take me less than an hour to cover at home in PA woods took me about three hours (with lots of stops for plant gawking and toad visits).
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| Note how the National Park section is book-ended by a power plant and shorefront homes. |
Notes:
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