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Autumn leaves its telltale colors

Every year I’m astounded at the vibrant display of fall foliage in this area. I guess I’m not the only one, I’ve seen an awful lot of people pulled over taking pictures of it everywhere I go.

At the end of August a few trees and shrubs started to turn on their autumn display indicating the approach of fall. By mid-September the colors really started to shine with flares of bright red, yellow, and orange amongst the generally green backdrop of the surrounding forest. It seemed like in just the past week the change has gone into overdrive into the peak of the fall color season.

During the fall the nights get longer and cooler, and set off a trigger in our deciduous plants. Deciduous plants generally drop their leaves in the fall in our area. The plants will start to produce less chlorophyll, the green pigment in the leaves that photosynthesizes the sunlight to make food for the plant. With less chlorophyll in the leaves, other pigments start to show through.

Yellows, oranges, and browns, are the result of pigments called carotenoids. These are the pigments that give color to many of our fruits and vegetables like the carrot.

The red colors come from another group of pigments known as anthocyanins. These anthocyanins give many plants and vegetables their red color. While chlorophyll and carotenoids are generally in the leaves all year, anthocyanins are mostly produced in the fall. Only particular plants and trees can produce anthocyanins and only under the right circumstances do they produce them well. That’s why some years the reds in the fall foliage are more vivid than other years. This year appears to be a good one in my opinion.

One reason we may arguably have the best fall colors around is due partly to the weather but also to the variety of trees we have in the Copper country. Different species of trees and shrubs produce different colors. The oak trees in our forests are generally in shades of reds and browns to anywhere in-between. Bushes and shrubs like dogwood, alder and sumac tend to be red. The large stands of birch and poplar in our area stand out with their bright gold and yellow while different species of maples can be anywhere from orange to yellow to red. Even ornamental plants folks have brought to the area can be vivid this time of year. Who doesn’t like to see a fire bush when it’s got the fall colors going? In the backdrop of all this we have our coniferous trees that continue to keep a touch of green. They remain green because the chlorophyll does not deplete and their needles are able to handle the cold of winter so they hang on to them. One fairly unique exception to this is the tamarack or larch tree. This tree has needles but later in the fall they will also run low on chlorophyll, turn yellow, and eventually drop to the ground.