Bayou-Diversity (30 September 2018) In a recent year the white oaks of Union Parish released their offspring on November 19th. Actually they began a few days before and continued for a week or so afterwards. On that day from my front porch my watch could not mark ten consecutive seconds free of acorn-fall within earshot. It was the largest acorn crop in 14 years for this naturally cyclic species. As they fell at speeds up to 100 miles per hour they riddled the leaves below them like arboreal hail and buried their butts in mother earth. Some blasted the metal roof of my house, accelerated on the 7/12 pitch, and launched off the edge of the front porch at a very unbotanical angle. Once on the ground their troubles just began. Acorn borers, fungi and other pathogens, birds, and mammals attacked this nutritional cornucopia with relish. Few survived.
Unlike their spring germinating red oak cousins, white oaks germinate in the autumn. A myth involving squirrels is entwined with this adaptation. Squirrels are commonly believed to assist in the planting of acorns as they bury them for winter food caches. However, gray squirrels are known to cut out the embryo of white oak acorns before they bury them. This keeps the acorn from germinating, which would result in a loss of food energy for the squirrel. Remarkably, fox squirrels do not excise the embryos of spring germinating red oak acorns.
I counted 25 acorns in a measured square foot in my front yard. Eight of them, by the way, were infested with acorn borers or were otherwise bad – better than normal. I also counted 44 white oak trees within 200 feet of my front porch. Each had an average crown of 1,300 square feet. Using my No. 2 lead calculator, the one with the pink eraser, I computed 1,430,000 acorns on the ground under the 44 trees. The 25 acorns that I collected weighed three ounces. All of the acorns in my yard thus weighed 10,725 pounds and probably a third of the crop was still on the trees.
In spite of this tremendous reproductive effort by nature, the probability of even one of these acorns growing into a mature tree was almost zero. The old trees in my yard produce deep shade, and oak seedlings are shade intolerant. This means that unless I cut down enough trees to allow sunlight to reach the forest floor, the seedlings will never get taller than a few inches. In natural conditions that rarely exist today, oak forests reproduced sporadically in tree-fall gaps. When an old, large tree fell its offspring grew up in the sunlit gap. The aesthetics of a giant fallen tree in the front yard is of no mind to Mother Nature. (adapted from Bayou-Diversity: Nature & People in the Louisiana Bayou Country; LSU Press)