Trees that stand up to the pressures of fall seem to be deciduous trees in temperate climates. These are trees that lose their leaves all at once during the fall and live in areas where the differences between the seasonal temperatures are not extreme.
Why Do Deciduous Trees Lose Their Leaves?
Botanists believe that deciduous trees lose their leaves so the energy that would normally be used to support the leaves is returned to the branches and twigs. The energy can be stored in the bare branches until the next spring. Losing leaves all at once also lets the tree conserve water during the winter, as water passes from the leaves into the air through transpiration. Whether a tree is deciduous or not also depends on the hardiness zone. Trees that lose their leaves in temperate climates might keep them in tropical or semitropical climates. This can be seen in trees of the oak family. The willow oak is deciduous in the northern part of its range, but at least semi-evergreen in the southern part of its range.
Many of these types of deciduous trees have spectacular fall colors because of these processes. The vein system in the leaf stops receiving nutrients and water, and the chlorophyll that made humans perceive the leaves as different shades of green starts to breakdown. This reveals other colors like yellows, oranges, reds and purples. These colors are created by pigments called anthocyanin, carotene and xanthophyll.
What About Evergreens?
Evergreen trees also do well during the fall. These trees also lose their leaves or needles but not all at once. They withstand the coming cold weather because the leaves have a tough layer of cells that protect them. Evergreens with needle-like leaves such as pines have less surface area that allow them to withstand very cold temperatures. This is why conifers can grow at elevations that broad leafed deciduous trees usually can’t. Broad leafed evergreens tend to grow in climates that are warm all year.
Some deciduous trees that can endure the fall are:
• Oak Trees
This is a huge family of trees. Many of the members, like the English oak, can live for hundreds of years. They are known for their acorns, which develop from the female flowers. Male and female flowers grow separately but on the same tree in the oak family. The wood of many types of oaks is used in construction and furniture making.
Maples can be trees or shrubs. The deciduous plants have opposite leaves, which are sometimes deeply lobed and sometimes toothed. The fruits are the familiar “keys,” which are blown away by the wind or carried by flowing water. Like the oak, the maple’s wood is used to make furniture, flooring and musical instruments.
The birch is grown as much for the beauty of its trunk as well as its leaves. Like the oak, the birch produces male and female flowers on the same tree, though the males come in the late autumn and only release their pollen in the spring. At that time, they form catkins called lamb’s tails. The female catkins are smaller and are found above the male catkins.
• Horse Chestnuts and Buckeyes
These deciduous trees are known for their beautiful “candles” of white or red flowers that appear in mid-spring. The fruits are the popular chestnuts.