Friday, February 25, 2011

Arkansas, Mississippi Vie for Bragging Rights to Largest Speciman of Fraudulent Species

I've written about Arkansas oak (Q. arkansana) before, a "species" with a suspiciously spotty range that looks like someone dripped a few ink blots from a leaky fountain pen across the southeast, skipping entire states in the process.

Of this spotty and dispersed range Oaks of North America says, "Arkansas oak is believed to be a relic of an ancient population which at some time in the past occurred over a much wider range than at present."  That, of course, is the charitable view of the situation.  The uncharitable view (e.g. mine) is that Arkansas oak is more likely a variety of another species, and that there is likely more variation between those widely dispersed pockets of Arkansas oak than there is between those pockets and the local populations of the species of which it is a variety.

My copy of Oaks of North America is copyrighted 1985.  At that time the National Champion Arkansas oak listed in the National Registry of Big Trees was located in Howard County, Arkansas:
138 inches circumference (approximately - I'm converting from metric and rounding)
62 feet tall
65 feet avg crown spread
NRBT score = Circumference (in) + Height (ft) + (Avg crown spread (ft) / 4)
= Score of 216.5

The other day good friend in Mississippi sent these photos:

(Click to enlarge)

Covington County, MS now claims the national champion Arkasas oak, nominated in 1997.  This is indeed the tree currently listed on the National Registry of Big Trees.  The scare as of 1997 was 253, and is now listed as 276.

There are a few interesting aspects to this.  The first is that while some range maps show Arkansas oak occurring in Mississippi, many others do not.  Of course if Arkansas oak is truly a species in its own right, and if it once had a much wider distribution, and if it now is in decline leaving only remnant pockets across its former range... then it seems completely plausible that some of these shrinking pockets would be in Mississippi.  In fact it seems somewhat implausible that there wouldn't be a few pockets there.

And, of course, this particular tree could have been planted there.  But that assumes either that someone quite a long time ago knowingly gathered acorns from one of those teeny-tiny populations of Arkansas oak and ultimately planted the sapling in Covington Cty MS, or that it happened simply by accident with the person assuming the acorns were of another species.  But if they thought they were planting a more common species, what are the odds that the seeds came from one of those tiny pockets of Arkansas oaks in another state?

To further pile assumptions upon assumptions to form a teetering tower of speculation, all of the above assumes that a) Arkansas oak is indeed a distinct species, and b) that this particular tree is indeed an Arkansas oak.

The friend who sent the photos, and who knows about a jillion times more about oaks than I do, wrote:  "(This tree) Looks just like a water oak but the spoon, paddle, or spatulate shaped leaves are "spoonier".  Ie the bottom of the leaves are more flared. Not in a million years would I have said " golly gee look at that Arkansas oak" if it didn't have a labeled sign in front of it. Looks like a water oak with SLIGHT variation to me."

The last thing I want to do is start a border battle among SEC conference states about trees.  It's not even something to joke about given the recent (alleged) poisoning of the oaks at Toomer's Corner in Auburn by a (indisputably) crazed (alleged) Alabama fan.

To me it just illustrates again the elastic and subjective nature of oak taxonomy.

I'm trying to contact some foresters in Howard County, Arkansas to learn if the tree that held the crown of largest Arkansas oak up until 1997 is still alive, and get its current measurements.  Then what I really want to do is to get twig, leaf and acorn samples from both trees, and from some surrounding water oaks in both locations.  I have a feeling that these two trees will have a lot more in common with their local Q. nigra brethren than they have with each other!

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