Beautiful fall foliage in Plumas County
Leaves on deciduous trees change color in the fall due to chemical changes that occur because of shorter, colder days.
The process of photosynthesis takes place in leaf cells that contain the green pigment chlorophyll.
Leaves also contain yellow and orange pigments such as carotene. Most of the year those colors are hidden by the preponderance of chlorophyll. But come fall, leaves stop producing food and conserve energy for the long cold winter. The chlorophyll breaks down, and the yellowish colors become visible.
At the same time, other chemical changes are occurring as well, causing yellow, red and even blue pigments to form.
Mixtures of pigments create the colorful palette of autumn leaves.
In Plumas County there are several varieties of trees that present brilliant foliage.
Willow, black cottonwood, quaking aspen, big leaf and silver maples range from yellow to orange to red and even purple.
Mountain dogwood adds splashes of red while California black oak contributes an orange hue. Indian rhubarb, found along creeks and wetlands, also adds a brilliant red to the carpet of leaves.
Some trees have leaves of different colors gracing their limbs. Leaf color may be affected by sunlight exposure, causing some leaves to turn red while others, in the shade, remain yellow.
Only a few regions in the world have showy fall displays. Eastern North America has large forests with broad-leaved deciduous trees and favorable weather conditions for vivid fall colors.
Some areas of western North American also have bright coloration, such as mountainous Plumas County.
Eastern Asia and southwestern Europe have colorful fall foliage too.
Adapted from “Why Leaves Change Color,” Forest Service bulletin 7078, July 2001.