Bumper crop feeds animals, insects and future fall color
As fall colors fade from the landscape, the bright yellows and oranges become a vivid memory marking the peak of the autumn season. As winter approaches, now is the time for the rich reds, burnt yellows and russet colors donned by the last of the deciduous trees to drop their foliage: the oaks. Always the last to leave the party in the fall and the most hesitant to sprout their leaves in the spring, the dominance of oaks in our forest cannot be denied.
This year has been significant for oaks for another reason. Anyone with an oak near their home or garden has certainly noticed the abundance of acorns this year. This is known as a mast year.
For scientists, why oaks produce prodigious amounts of acorns in a mast year is not clear. To further confound the phenomenon is the fact that in a mast year the oaks tend to synchronize their behavior over a vast geographical area and across multiple species.
Are the trees simply being generous to the plentitude of hungry, acorn-loving animals of the forest? Not really, but by satiating the hunger of their predators, the trees ensure a greater likelihood that some of their offspring may escape consumption and live to sprout and grow.
Scientists have not yet discovered the trigger for mast years or determined how the synchrony is determined, though weather patterns, pollination success, and temperature fluctuations have all been investigated.
The value of oaks goes beyond their stimulating fall color and their ability to both feed the hungry masses and supply a cozy home for cavity nesters — hordes of hungry insects prefer to dine on the foliage of oaks more than on any other tree species. One count generated by the studies of Dr. Douglas Tallamy put the number of oak-loving insects at more than 534 different species.
Perhaps this does not sound so wonderful to you — who wants a hungry legion of insects to take up residence in their garden? The answer is the lovely troupe of birds and furry friends that require these protein-packed bugs for their dinner and to support their families. The ecological trickle-down effect of oaks, not to mention their fall color and summer shade, make majestic oaks an excellent addition to any yard.
Contributed by Sonya Carpenter, Highlands Biological Foundation director