Unleafing the Trees in Autumn

This time of year is probably called fall because that is what leaves do, and they seem to do it enthusiastically. While some folks grumble about raking them into piles and removing them, there are many who go on color tours to see the golds, reds, and browns on the trees.

It may seem like a simple performance. The trees decide it is time to let go, colors change, and leaves fall. Much of that is influenced by regional climate. Leaf changing and dropping exhibits the planning of the Master Engineer for trees' protection.

Beginning autumn, Hudson River Overlook at Shaupeneak Ridge, Unsplash / Cowboy Bob Sorensen

There is a lot happening that is hidden from observers. Leaves grew out to gather sunlight and collect water for the trees in spring. Those leaves are full of nutrients. When it is time for the seasons to change, trees begin withdrawing nutrients. There are also actions inside the leaves to produce the colors. (I think those colors are another example of God's benevolence to give pleasure to people.) Of course, some will claim "It evolved," but they do not give any explanation of how the process evolved.

In Autumn, deciduous1 trees don’t lose their leaves—they loose them.

It is the final step in a highly ordered and carefully controlled process initiated in preparation for a resting period (winter) in above-ground portions of the tree.

. . .  

With the post-summer hint of coolness in the air, before the onset of wintry weather, trees initiate a “senescence sequence”2 to systematically retrieve the re-usable resources from the leaves. As this process begins, and the green chlorophyll pigment and other parts of the light-harvesting (photosynthetic) complex4 are dismantled, the leaf changes colour.

To read the entire article, drop in on "Autumn leaves don’t Fall (by accident)."