This has been a beautiful autumn in the Tehachapi Mountains. Conditions have been right for our local trees to develop and sustain a vibrant range of red, yellow, scarlet, golden and purple leaves.

As I have mentioned before, fall didn't used to be this colorful in the Tehachapi Mountains. Some of our native trees like Fremont Cottonwoods, Arroyo Willows, Valley Oaks and Black Oaks can display bright glowing shades of yellow and amber, but red is uncommon, except for in some shrubs like Chokecherry and Poison Oak.

In more recent decades, however, residents, business owners and agencies like the city of Tehachapi have planted thousands of deciduous broadleaf trees that do develop beautiful shades of crimson, ruby, russet, vermilion and assorted reddish tones. Other ornamental trees contribute more bright yellow and golden foliage into the autumn palette.

As a result, fall in Tehachapi has become decidedly more colorful. Assorted maples, oaks, dogwoods, aspens and birches, as well as trees like Liquid Amber and Crepe Myrtle, have enriched and diversified the complexion of our tree canopy.

During the growing season, of course, tree leaves are green, with a few exceptions like purple-leaf plum trees. The green comes from chlorophyll, the pigment that helps trees absorb energy from sunlight. Chlorophyll is continually produced and broken down throughout spring, summer and early fall.

But as the days get shorter and the nights get colder, chlorophyll production shuts down and the green pigment is gradually lost and not replaced. This process begins to reveal the carotenoids, which are pigments that give carrots their distinctive orange color and are present in many leaves.

With the absence of chlorophyll, the carotenoids become visible, creating a variety of shades of yellow, orange and brown. The reds and purples are created by anthocyanins, another group of pigments — these are the ones that create the red in red apples, strawberries, cherries, cranberries, etc. Unlike carotenoids, they are not present in the leaves all season, but are mostly produced in the waning days of the leaf's existence, as the plant sugars manufactured by chlorophyll begin to break down.

The best weather conditions for vivid autumn colors are cool nights and warm days, without too many hard frosts, which is exactly the conditions that the Tehachapi area has had this fall. We did have one killing frost in late October that took out the tomato vines and other more sensitive annuals, but since then we haven't had many freezing temperatures.

The welcome 1.25 inches of rain that fell about three weeks ago also seems to have helped trees hang onto to their leaves a little longer, so this has been an especially long, colorful fall with lots of beautiful trees throughout town and in the surrounding communities.

Humans are better known for diminishing rather than improving the natural beauty of an area once they move in, but in the case of fall leaf displays, the planting of so many hundreds of ornamental deciduous trees has made the Tehachapis more multicolored and vibrant. I looked down on the Tehachapi Valley last week from up in the mountains outside of town, and was delighted by all the autumn colors.

Have a good week.

Jon Hammond has written for Tehachapi News for more than 30 years. Send email to tehachapimtnlover@gmail.com.