In the fields of botany and horticulture, deciduous plants are trees, shrubs and herbaceous perennials which lose all of their leaves for part of the year, usually in the autumn.
In horticulture and botany, the term deciduous means “falling off at maturity” and “tending to fall off”.
“Deciduous” has a similar meaning when referring to animal parts, such as deciduous antlers in deer, deciduous teeth (baby teeth) in some mammals (including humans) – or decidua, the uterine lining that sheds off after birth.
The antonym of deciduous in the botanical sense is evergreen.
Leaves are the most important organs of most plants. They are usually borne above ground and specialized for photosynthesis. They are mostly green in color. This is due to the presence of a compound called chlorophyll. This compound is essential for photosynthesis as it absorbs light energy from the sun.
During the autumn, deciduous plants change color and then lose their leaves. Because of changes in the length of daylight and changes in temperature, the leaves stop their food-making process. The chlorophyll breaks down, the green color disappears, and the yellow to orange colors become visible and give the leaves part of their fall splendor.
Because it gets so cold, the deciduous plants have adapted to the winter by going into a period of dormancy or sleep.
Deciduous species in temperate and Arctic zones lose their leaves at the end of the growing season due to the onset of winter. In tropical, subtropical, and arid regions, deciduous lose their leaves during the dry season or other seasons, depending on variations in rainfall.
There is a cost to dropping leaves, which is why some perennial plants are not deciduous. It can take a lot of nutrients from the soil to produce the number of leaves produced in an average growing season. In areas where nutrients are plentiful, an annual leaf drop is not a problem. However, in areas with nutrient poor soils, dropping leaves may be very costly for the plant.
Many deciduous plants flower during the period when they are leafless, as this increases the effectiveness of pollination. The absence of leaves improves wind transmission of pollen for wind-pollinated plants and ncreases the visibility of the flowers to insects in insect-pollinated plants.
A deciduous forest is a biome dominated by deciduous trees which lose their leaves seasonally. It is found in three middle-latitude regions with a temperate climate characterized by a winter season and year-round precipitation. Most deciduous forests are located in the eastern United States, Canada, Europe, China, Japan, and parts of Russia.
While Americans typically use the word “fall,” the British use the word “autumn,” though both terms date around the 16th century. Before these terms, the period was called “harvest.” The word “harvest” comes from the Old Norse word haust, which means “to gather or pluck.” As people moved to the cities, “harvest” fell out of use and city dwellers began to use “fall of the leaf,” which was shortened to “fall.”
Leaf peeping is an informal term in the United States for the activity in which people travel to view and photograph the fall foliage. A similar custom in Japan is called momijigari (紅葉狩).
In some areas of Canada and the United States, “leaf peeping” tourism is a major contribution to economic activity. This tourist activity occurs between the beginning of color changes and the onset of leaf fall, usually around September and October in the Northern Hemisphere and April to May in the Southern Hemisphere.