Tag: mast

The Last Leaves of the Season

Another year has cycled through, and the canopy of colorful leaves around my house is now a carpet in different shades of brown.  From the mighty white oaks to the humble dogwoods, all sport naked limbs, awaiting the return of spring to unfurl new green leaves.  

But one tree stands out in the forest.  The American Beech (Fagus grandifolia) holds on to its withered tan leaves throughout the dormant season.  This quality of holding on to dead leaves after other plants have shed them is called “marcescence”.  Studies suggest marcescence is a strategy for deterring deer and other herbivores from browsing on the more nutritious twigs and buds, or perhaps for improving the tree’s nutrient uptake by delaying leaf decomposition until spring. 

The beech is one of the most shade tolerant of trees, allowing it to spend decades holding its own beneath the forest canopy until a fallen tree gives it an opening to grow into the light.  The beech prefers moderately moist conditions, and its thin bark provides scant protection against fire.  In open woodlands of the precolonial Piedmont, oaks dominated, while beeches withdrew to the more sheltered bottomlands.  With fire removed from hardwood forests, beeches, maples, and other thin-barked trees advanced into the uplands as forest canopies closed.  They are firmly part of the climax forest community.   

Beechnuts are a much-sought-after food for birds and mammals, from blue jays to black bears.  It was a primary fall food source for the long-vanished passenger pigeon. Humans make vegetable oil from beechnuts, or roast them to eat or to make a caffeine-free coffee substitute.  Unfortunately, a seedling will grow for several decades before putting on the first beechnuts, and thereafter produce at intervals ranging from two to eight years. Beeches can live for 400 years, assuming they aren’t cut for lumber or high-quality firewood, or succumb to one of several introduced disease-causing pests.

The bark of the beech is relatively smooth and pale gray, making it a tempting canvas on which folks may carve their initials, dates, or other sentiments.  I don’t recommend the practice — cutting the bark allows pathogens to attack the tree, and it’s rude to future visitors — but don’t be surprised to see the declarations of love, territory or simple presence written across a trunk. Yesterday, I walked downstream a short way to a beech tree I remember from my youth; decades ago, a local with the surname Inglett took knife to bark, staking his claim on that patch of woods.  I don’t know how long ago this bit of vandalism occurred, but the scars were old when I was a kid, and they have stretched to near illegibility since then.

When you pass through the woods this winter, Keep an eye out for marcescent leaves of beeches.

Falling Acorns

Although summer has continued its fierce rearguard action well past a reasonable concession date, autumn is here.  True to the colloquial name, “fall”, the trees are divesting themselves. But I’m not talking about leaves; there is still a lot of green in the trees at the moment.  I’m looking at acorns, specifically white oak acorns.

The white oak (Quercus alba) is an all-around excellent tree.  Large, long-lived, and handsome, much can be said about this species and its lumber (including being crucial for bourbon barrels and earning USS Constitution its “Old Ironsides” nickname).  But on this October day I want to talk about the nut of the oak. 

White oaks are the flagship of a cluster of species known as the white oak group (which include English oak, burr oak, post oak, overcup oak, and scores of others), as opposed to the red oak group (locally represented by the southern red oak, northern red oak, water oak, pin oak, and others). White oaks produce acorns on a one-year cycle – that is, spring blooms will develop into acorns in the early autumn, while red oaks take two years to produce.  Red oak acorns tend to drop later in the season, and are much more bitter due to the higher tannin content.  On the plus side, red oak acorns will be available to deer during the hungry months before green-up, while white oak acorns germinate soon after hitting the forest floor.

White oak acorns have been falling in prodigious quantities for a couple of weeks now.  The tree which stands closer to the house than the deer like to venture has carpeted the ground with the leathery brown nuts. This is definitely a good mast year (“mast” is the collective term for nuts, berries and seeds from trees that are eaten by wildlife) for white oaks.  You see, oak mast production is hit-and-miss; several years may go by before there is a bumper acorn crop for a given locale and species.  Acorns are sought after by a great many birds and mammals, so on an average year few if any acorns will actually make it to germination.  Periodically, a super-abundant crop of acorns will flood the market as it were, providing more nuts than wildlife can consume or stockpile, and increasing the chance that a tree’s attempt at reproducing will be successful.  Naturally, the extra food is welcomed by turkeys, deer, squirrels, jays, and other hungry critters.  It’s good for wildlife when there are several oak species in the local forest – if the northern red oak is a bust this fall, perhaps the scarlet oak will be a boom. 

This is a good year for the critters to fatten up on white oak acorns.  We’ll soon see if the red oaks will call, raise, or fold.