Thursday, August 3, 2017

What is a "Microclimate"... Part 1

 Or what is a "Micro-ecosystem" (or "Microbiome" or "Cryptobiome")?  Or perhaps a "Meso-ecosystem" or "Macro-ecosystem"?

(Am I over-thinking this?)

It is about learning about big systems (or big things) by observing little systems (little things).

Wikipedia defines "Microclimate" as: "A microclimate is a local atmospheric zone where the climate differs from the surrounding area.  The term may refer to areas as small as a few square meters or square feet (for example a garden bed) or as large as many square kilometers or square miles."

Herein is where I quibble with this otherwise good definition, over the vague word "many" in reference to square kilometers or miles.  [This quibble as well as further descriptions of Microclimate and Micro-ecosystem characteristics will be discussed in Part 2.]

I first became aware of the concept of "Microclimate" in the 1970s, while at Georgia Southern College.  While visiting my parents' home, I observed some very small mushrooms - Coprinellus disseminatus, smaller relatives of "Parasol mushrooms" - growing within the shade of a large "Tulip Poplar" tree, at the margin of the turnaround.  [The turnaround's semi-circular outer margin was ringed with about two feet of rich soil and leaf debris.]  I also observed that the mushroom grew nowhere else in the surrounding woods.

[Back at college, while describing the observations, a friend (with double majors in Biology and Geology) explained the concept of "Microclimates".]

Woods surrounding the family homeplace were a classic Piedmont "transition forest", within the regional Temperate Deciduous Biome.  And within the shade of this large hardwood tree was the only place where the mushrooms grew.  [The "magic" of growing up on this semi-rural, partially-wooded 6.67 acre lot will be discussed in later posts.]

Within the surrounding area, dominated by a canopy of mature Loblolly Pines, with scattered Shortleaf Pines, Tulip Poplars, small Maples and Sweetgums, and a few juvenile examples of other hardwoods, the leaf coverage was open enough to allow the soil to dry somewhat between rainstorms, especially beneath the pines.

However, the Tulip Poplar's heavier leaf-coverage kept the underlying soil moist, to the benefit of the mushrooms.  So, in this case, less soil moisture (as a factor of less sunlight and lower temperatures) defined this particular "Microclimate/Micro-ecosystem.  To further illustrate this point, in June 1983, the Tulip Poplar was struck by lightning and subsequently died.  With the canopy leaf-cover gone, "Microclimate change" occurred and the small mushrooms no longer grew.

To offer further evidence of "nature's way", a few years earlier during late Summer, my Mom had collected some Black Walnuts, with the idea using them in cooking.  As time went by and other chores superceded the "walnut plan", she dumped them over the edge of the turnaround margin.  One of the walnuts sprouted and by the time of the poplar's demise, it was healthy sapling, though stunted by the lack of sunlight.  With nature's removal of leaf-cover and the human removal of the dead poplar (for safety reasons), within a few years, the Black Walnut tree had acquired early characteristics of a good "shade tree".

[Sadly, with the passage of time, natural and human events intervened.  In April 1998, a tornado took down an estimated 55% of the mature pine trees, with more lost during a subsequent ice storm in January 2000.  After my Mom's passing in late 2000, various taxes and development pressures resulted in the land's sale (along with an adjacent lot) to developers in 2002 or 2003, following which subdivision development took place.  So it goes.]

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