58: Glacial Influence

Helen Allison Savanna, East Bethel, Minnesota

E.  B E T H E L,  M N

Twenty thousand years ago, Canada and northern America were covered in ice.  The earth had cooled, crystallizing much of its water into massive and impressive ice sheets, known commonly as the Ice Age.  But then the pendulum began to swing.  Slowly, the earth has been heating up ever since.  Science hasn’t yet figured out the reason for this rise - a natural ebb and flow, perhaps?  Despite popular belief, the tons of carbon we dump into the atmosphere is only an exacerbation – the earth had been naturally heating up well before we cut down a first tree or drilled for even an ounce of oil. 

Regardless of why, as the earth warmed, the ice sheets retreated leaving behind dramatic landscape changes.  In one particular state, those changes included the formation of 10,000 lakes.  Few states have been influenced more by glaciation than Minnesota.  Here too, the forward and back grinding action of the massive ice sheets has left behind an accumulation of fine sand.  North of St. Paul that accumulation is known as the Anoka Sandplain.

The Nature Conservancy’s Helen Allison Savanna in Anoka County twenty miles north of St. Paul is a prime example of the state’s glacial influence.  The undulating, sandy-soiled hills and small grassy lakes have fostered a healthy oak savanna.  Oak savannas in this part of the country are rare.  Today, less than 65,000 acres remain in the Midwest - less than one percent of what existed pre-settlement.

Plainly put, savannas are ideally suited for wandering about.  The tall canopies and low understories leave plenty of open mid-story affording abundant eye-level clear space.  Like the pine savannas in Virginia, North Carolina and Florida, a stroll through these environments is complete joy. 

My binoculars – a new accoutrement now that I’ve completed a master naturalist training program – are busily employed as I walk slowly though the partially frozen dewy grass.  Through the lenses I spot these commonly found animals: white tail deer, squirrels, blue jays, and goldfinches.   And these much-less common birds – a Northern Shrike and a pair of Trumpeter Swans.  Checking field guides, I find these birds are really quite rare in this part of Minnesota and nice finds I would have missed had I not just sat through seventy hours of training. 

Thirty five years ago, when I first set out alone in the woods, my goals were much different than today.  Distance, speed, and a collecting overlooks were the drivers; double digit distances were the standard.  Push, push push. 

But when I discovered photography and then later a dedication to trail maintenance, distance no longer was a driver.  For several years my woods walks stayed under five miles.  The slower pace was nice.  I began to see more and ache less, and along with that came a more-concentrated zest.

Now, attuned to the plentiful knowledge acquired through master naturalist training, simply stepping outside, looking and listening to bird calls, identifying a tree, or understanding the geology before me are the new drivers.  Walks in the woods need not go very far at all.  A short stroll to a pond’s edge with binoculars in hand is now as zesty as the speed hikes or photo excursions of years ago.  The slowing pace has more clearly revealed nature’s richness.   

Another accoutrement in my backpack is a high-quality Zoom H1n sound recorder.  A few months back, The Nature Conservancy’s Cool Green Science blog included a story about Lang Elliott’s sound recordings captured in Aravaipa Canyon in Arizona – a place I drove past during my 2016 sabbatical.  Simply put, I’m hooked and have begun a quest of capturing my own recordings of similar serenity.  Unfortunately, though the Helen Allison Savanna is a beautifully natural place full of wonderful sounds, it suffers from a too-consistent noise pollution.  Even the thin country roads bordering the property produce enough unnatural noise during the morning commute to disrupt a quality recording.   But continuing to have a recorder in my pack as I visit future sites will now bring a new way in which to judge a property’s character. 

LEARN MORE ABOUT TNC’S WORK AT THE SAVANNA HERE.