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Forest Controversies
Article #364 November 2024
By Bill Cook

You’ve seen them in the movies and Halloween cartoons.  They’re big.  Their branches are bare and gnarly.  So, there lies the kernel of spookiness. 

    In the 1982 film “Poltergeist”, a seemingly sentient tree, with evil overtones, was brushing the bedroom window of the five-year-old character Carol Anne.  In the darkness, the effect was ominous, portending an unpleasant near future.  And then in another story, a headless horseman pursues Ichabod Crane through a forest of threatening trees.  This 1820 short story has been repeated and modified numerous times.  The creepy forest is almost an American icon.
    As a forester, I unnaturally focus on the question of “What species are those trees?”  In my mind, they are bur oaks or, possibly in some cases, chestnuts.  Most of the big old chestnuts disappeared from the American forests over a century ago.  So, for the most part, I’m going with bur oaks. 
    Now, bur oak has an interesting natural history.  Best known, maybe, is its role in “oak openings” of the eastern prairies.  Prone to regular fires, few trees could survive on these rich soils that now grow corn and soybeans.  Bur oaks have thick corky bark, even on saplings.  This nearly fireproof coat protects the trees from all but the most severe wildfires.  The crown pattern of large trees appears crooked and bent, with fewer branches than most trees, rendering a morbid look to those with accommodating imaginations. 
    As settlers migrated across these broad prairies, the open stands of large bur oak provided the scant shade that sheltered them from the scorching summer sun.  The grandmother trees, often over 300 years old, lofted expansive crowns held high by stout branches gnarled by the perpetual prairie winds.  Church picnics and many a marriage proposal undoubtedly occurred under this shade. 
    Where these stands of “oak openings” were not plowed under, they now exist hidden among invading tree species that survive only due to the cessation of the “cleansing” prairie fires.  The Midewin National Tall Grass Prairie, in Illinois, has restored some of the original prairie but has failed to release the monster oaks from the “non-native” usurping tree species, such as hickories, cherries, and walnuts.  Yet, if you look carefully, the old oak openings can be seen, although the old veterans are now dying of old age, with few or no saplings for the future. 
    However, bur oaks also grow on bottomland soils, sometimes with associates such as butternut, silver maple, sycamore, gum, and others.  They can be seen in our northern forests, too, often along waterways and isolated patches among wetlands.  There are several giant bur oaks among the northern hardwoods on the Dunbar Forest of the eastern Upper Peninsula.  “Islands” of bur oak mixed with aspen and balsam poplar also occur on the forest edges of Minnesota and within the patterned peatlands north of the Red Lakes. 
    The more common white oak can sometimes be mistaken for bur oak.  Michigan oak savannahs and oak barrens are uncommon habitats where prescribed fires are employed to maintain these special conditions.  While white oak may dominate, bur oaks may be present as well.  Bur oak twigs will have ridges and flanges of protective bark.  White oak will not.  Both oak species have leaves with blunt lobes, but the bur oaks have deep sinuses midway down the leaf, cut nearly to the mid-vein. 
    Most hardwood forests with monster-sized trees can appear spooky, especially on a dark night aglow with a full moon or in a crepuscular dense fog.  Any forest dominated by oaks stimulates particularly vivid imaginations of paranormal threats lurking just behind the next massive trunk.  However, the twisted and purled canopy structure of bur oak is, by far, the scariest. 
    If you’re lucky enough to visit an open stand of bur oak, it’s fun to engage in an evening of ghost stories over a flickering campfire under the creaking branches and whispering breeze.  The telltale sounds and smells of a moldering autumn night might just shiver your timbers in the manner that caught young Carol Anne.  You never know, perhaps something really is there? 

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Corky bark of a young bur oak.