(WYTV) – Why do evergreen trees keep their needles while other trees lose their leaves in the fall?
Evergreens — the pines, the firs, the junipers and spruces — are immune to seasonal leaf changes and shedding.
Deciduous trees — the aspens, oak, maple — are not.
Remember your biology class in high school and the term photosynthesis.
Both deciduous and evergreen trees use energy from the sun and water from the ground to turn carbon dioxide in the air into food.
During the fall and winter, all trees get less sun, so the deciduous trees with broad, flat leaves go dormant. They shed their leaves to help them conserve water and stay alive until spring arrives.
New leaves grow from new buds.
But in the evergreen tree, the needles are actually tightly rolled leaves, and this shape helps the needles conserve water throughout the fall and winter. They have a waxy coating to help keep water from evaporating.
These rolled-up, waxy needles resist cold and stay moist, which keeps them green throughout the winter.
You can find evergreens on every continent except Antarctica.
Evergreens offer shelter to birds and small animals when the weather is cold, and many of these trees are thick enough to serve as windbreaks. They make a great Christmas tree, too.