There are several events that occur in the fall, making it a beautiful and interesting season, a season of harvest, and a season of holidays. The bounty of the harvest and Thanksgiving time are reminders of appreciation in this season.
The weather begins to change, though it is still a mild season. The wind begins to blow, and leaves fall from the gentle persuasion of Mother Nature. With the winds and cooling weather, there is also a shortening of the daylight. The changing of the fall colors of the foliage is a pleasant event wherever it can be found.
The growing of large pumpkins for decorating is a sign of the autumn season as well as the scent of warm, spiced pumpkin pies.
The Autumn Equinox
The equinox occurs twice a year when the tilt of the earth’s axis is inclined neither away from nor towards the sun. Night and day are approximately equal at the time of an equinox.
The terms of these two occurrences in the year are the autumnal equinox and the vernal equinox which occur six months apart.
Around the autumnal equinox the Chinese Mid-Autumn Festival is held. This is a major harvest celebration which falls on the 15th day of the 8th month of the Chinese lunar calendar. It is also the time of the Vietnamese Tet Trung Thu holiday.
These Chinese/Vietnamese holidays are also known as the Moon Festivals, and go back as far as 3000 years.
Lessons from Autumn Leaves
Trees that drop their leaves in each autumn are called deciduous trees. Why do dentists refer to baby teeth as deciduous teeth? In Latin “deciduous” means falling.
In the summer, the chemical make-up of leaves is actually yellow, orange and green at the same time. The pigment chlorophyll (the pigment that makes the leaves green) is a much stronger pigment than the yellow and orange pigments in the summer.
The green pigment covers the yellow (xanthophyll) and orange (carotene) pigments that are part of the tree's leaves and can be seen in the fall when the tree produces less chlorophyll for the leaves.
The pigment anthocyanin, which produces reds and purples, isn't present all year long in most green leaves. It only appears as the nights get cooler.
Why Do Leaves Fall From Trees?
Leaves are actually “cut off” from the trees, they don’t just fall off.
Deciduous trees use a cellular mechanism to part company from their leaves, which act as solar cells for solar heating and processes in the summer but become unnecessary in the darker winter months when they cannot gather as much sunlight.
At the base of each leaf is a special layer called the abscission zone. When the time comes in autumn to shed a leaf, cells in this layer begin to swell, slowing the transport of nutrients between the tree and leaf.
Once the abscission zone has been blocked, a tear line forms and moves downwards, until eventually the leaf is blown away or falls off. A protective layer seals the wound, preventing water from evaporating and bugs from getting in.
Pumpkin Season
In North America, the large gourd-like squash known as a pumpkin begins to appear as colorful globes on the ground which is now without much foliage.
In October, Halloween customs surround the pumpkin - activities such as carving jack o’ lanterns, and decorating with pumpkins.
Then also begins the season of making pumpkin pies, a favorite dessert in the fall from Halloween to Thanksgiving.
Paula I. Nielson - Paula I. Nielson, Ph.D., holds credentials and interests in anthropology, archaeology, religion, the Middle East and Asia.
