This year, the oak trees were nature’s underachievers.
Naturalists, landscapers and backyard rakers noticed a lack of acorns this fall. No apocalypse, unless you are a squirrel, but of interest nevertheless.
The low number of nuts was in great contrast to the thunderous falling of acorns last year, which was a mast, or boom year. This strategy of bumper crop year followed by a sparse year (or years) is a method by which to keep the oaks’ predator population in check. By limiting the amount of food available to their predators, the oaks are essentially forcing those creatures to either choose a different food source, move on to other feeding grounds, or else reduce their population.
Then, in a brilliant play, the oak trees put out extraordinary amounts of seed in a subsequent year. The acorns now have a greater chance of growing into trees rather than being eaten, because of the reduced predator population.
Even if you don’t find many acorns, there is another tree whose production rarely lets you down. Count on the conifers to be creative and the pine trees to provide!
Conifers are cone-bearing trees. They are generally evergreen and have modified leaves that are scaly or needle-like. Within this group are the pine trees, whose seed output comes on the wings, scientifically known as scales, of pine cones.
Pine cones, unlike acorns, are plentiful this year. The most common cones found in our woods and on our trails are those of the white and pitch pine trees. Differentiate the two by the length of the cones: the longer, slimmer one will be the white pine.
Pine trees have no true flower or fruit; instead, their reproductive structures are found inside of the cone, or strobilus. The woody cones that you commonly see house the ovule, thus the hard cones are all female. These megastrobiluses (female cones) are where fertilization takes place and the developing seed is found. The cone itself can take up to two years to fully develop and become ready to receive pollen.
The male organs, or microstobilus, are more subtle in the case of pines and most other conifers. They are softer, more pliable and less rigid than the true cones of the female and produce the wind-borne pollen that will fertilize the seed within the scales of the female cone. They are also not long-lived, and will dry up after their work is done. Once the wind-borne pollen finds the ovule, a new seed will develop within the scale of the hard cone, to be released when the scales dry and open up.
Beyond their reproductive necessity, pine cones are also part of a mathematical morass known as the Fibonacci number sequence. (I say morass because the Fibonacci sequence taxes my mathematically-challenged mind.)
This sequence, which was defined by mathematician Leonardo Fibonacci, appears repeatedly in nature, and is found extensively in art and architecture. It is the sequence of numbers that you’ll arrive at if you start with 0, then add 1, and from then on add together the previous two numbers in the sequence to produce the next number: 0, 1, 1, 2, 3, 5, 8, 13, 21, etc.
Fibonacci numbers follow this established pattern, and occur often in nature. The pine cone is just one example. If you count the spirals (not the scales) in either direction from the bottom of the cone, it will always be a Fibonacci number (often 8 or 13, in the case of our local cones).
How nature multiplies itself within the confines of the Fibonacci sequence may be seen elsewhere. Population increases of animals such as rabbits and bees follow this sequence, as do the numbers of petals and leaves on some plants, seed heads, and even shell spirals.
It all may seem a bit nutty, but the point is that the seemingly random behavior of acorn yields or pine cone spirals may actually reflect an underlying logic, to those with the patience (and math skills) to delve into them. And for the rest of us, there is comfort in knowing you don’t have to know the formula of nature to appreciate it.
Suzan Bellincampi is director of the Felix Neck Wildlife Sanctuary in Edgartown.