Leafy thoughts on a bowhunting morn
Studying autumn color is a good way for bowhunters, who typically spend hours and hours in treestands or groundblinds waiting for the Big Something to happen, to help pass the hours.
Knowing the story about leaf color-change is a fascinating one, and can deepen your appreciation of the gift of time afield. The sudden switch from summer green to autumn bronze, red, yellow, and maroon on the trees is an intricate, brilliant process – even if it has nothing to do with the mythical Jack Frost.
Indeed, a frost is not at all behind the color change. In fact, frosts weaken leaf-attachments to stems and branches and twigs and that prompts leaf-fall, not color-change. Being a deciduous, or leaf-bearing, tree is a lot of work, work that takes up a lot of energy. So, in the cold of winter, it is just not practical for a tree to maintain healthy green leaves.
Thus trees reabsorb their nutrients and drop their leaves for a long winter dormancy, growing new leaves when warmer, sunnier weather returns come spring.
The key to autumn color-change actually is linked to shorter days and cooler weather. Plants respond to the seasonal changes in light-and dark-cycles. Shorter, cooler days are signal that it is time to cease making chlorophyll, the light-absorbing, food-making substance of plant-cells responsible for making leaves green. As chlorophyll levels subside, other color-pigments, which were masked by the green of chlorophyll, begin to show off.
Leaf-pigments called carotenoids are yellow and orange, and also are found in squash and pumpkins. Anthocyanins, an antioxidant responsible for the deep colors of red wine or purple farm-market carrots, are the pigments of red, pink, or purple colors.
Some tree species, of course, do not change color, even with colder weather. They are the conifers – tree species with needles, not leaves, such as various pines, spruces, and firs. Unlike the “broadleaves” – such as oaks, maples, hickories, and such – most conifers bear sticky, resinous sap that works like a natural antifreeze to help them stay green all winter and through the rest of the year.
Understanding the chemistry behind color-change also can lead to further reflections from a treestand or blind – as in just which trees are those that turn yellow, or orange, or red, or bronze, or purple? Not all trees bear the same combinations of pigments in their leaves, and thus, show different colors.
Such wool gathering all helps pass the hours until Big Something sashays within range, and helps to brilliantly illustrate the ingenuity of nature.