Wednesday, May 24, 2006

A Run in the Woods, Part I

In the 1980's, entomologist E.O. Wilson introduced a concept known as "biophilia," a hypothesis that suggests that human beings have an instinctive bond with other living systems. The startling idea that our love of the natural world is literally melded into our hardwiring.

An aspect of my personal biophilic tenedencies (that only sounds bad) involves land. I simply love land--its topography, flora, history, human provenance, character. My desire to more deeply explore these elements led to a specialty while studying History in grad school of Environmental History and Historical Geography, two closely related methodologies, the former using traditional historical research while borrowing from diverse scientific fields in a quest to explore how humans and "nature" have interacted, while the latter being the specific study of how a place changes over time.

All ecosystems have a story, but my primary interest lies with the Grand Prairie Section of my home in Illinois, to which I try and apply my historical training to better understand. On my many runs through the woods, the main question often framed in my mind is: "Just what am I looking at and experiencing?" Further, how have these landscapes come about and where do we go from this point? I hear from environmentallly minded folks all the time suggesting that we in the Midwest destroyed an entire prairie ecosystem in the matter of a few decades, and are in the process of desertifying what currently exists. In a way, yes, it is true, the tallgrass prairie/oak dominated lowlands are gone, almost entirely cultivated and logged since the mid-1800's (I did an entire thesis on this, but the details will be spared for now) but the fact is that all ecosystems are in a perpetual state of change.

We tend to romanticize "The Prairie" as being the paragon of pre-settlement ecological purity, the unspoiled wilderness defiled by pioneer hands. This simply isn't the case. I'm willing to set aside practices by native peoples such as burning, canal digging, damming of waterways, hunting and fishing of numerous animal species, all things that date back 100's of years before large scale settlement, and focus more on the effect of natural cycles on this particular environment.

In Illinois, glaciation has been the main sculptor of our topography during the 1.8 million years of the Pleistocene, the Illinoisian and Wisconsinian periods, from 180,000 to 17,000 years ago, being largely responsible for our current land forms.

The ice sheets reached their southern terminus near modern day Shelbyville, IL about 24,000 years ago. From that point northward retreating ice had the affect of a box scraper, in simplistic terms, levelling the uplands and leaving bogs and rudimentary waterways that drained glacial meltoff, these being constantly carved and then re-carved.

If I were to have stood in central Illinois in say, 15,000 BC or so, I wouldn't observe even the embryonic stage of the tallgrass prairie. Glacial and interglacial moisture and climatic conditions assured a completely dynamic patchwork of forests and tundra.

When I reach back into my being to the post-Illinoisan period, I can feel the cool, crisp air and smell the freshness of the developing spruce and pine forest, a scene similar to what exists today in southern Canada.

During the interglacial, as the climate warmed and moistened, a deciduous forest consisting primarily of oak, elm and hickory took hold. The pre-Wisconsin period ushered back cooler conditions and pollen samples dated from 30,000 years ago tell us that the coming ice razed a mature spruce forest, leaving a chain of meltwater lakes and swamps, then a tundra of sedge interlaced with the spruce remnants.

Analysis indicates that the resultant drying and cooling allowed an ash dominted forest makeup until around 10,000 BC, at which time dryer air brought back an oak/hickory/elm makeup that was able to dominate until 4,000-1,500 BC, when grasses gained a foothold in the uplands, leaving groves of oak forests as large islands and continued predominance of forest in the low areas where fire could not entirely penetrate--finally the "prairie" mosaic of our collective mythological imaginations--the land that the Illinois tribe and later bands of both Potawatomi and Kickapoo lived, hunted, celebrated and died on--the land my grandparents tilled, where I, as a postmodern man, seek my running refuge on. be continued

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