Why Do Trees Lose Their Leaves?

Piles of leaves are either a chore to clean up or a pleasure to jump into, depending who you are. Each fall, leaves throughout the world turn bright orange, red and yellows displaying the best of fall colors before losing their leaves and scattering the ground with a natural multch. It’s a natural pattern that has meaning in the world. So why do trees lose their leaves in the Fall? Firstly, not all trees lose their leaves, only deciduous trees. The always green evergreens don’t have leaves and keep their green bows throughout the year.

A pile of leaves is one of Fall’s best pastimes for a kid.

Deciduous trees get their nutrition from the sun through their leaves. As winter time approaches and the sun’s rays are more scarce, a deciduous tree will drop its leaves out of necessity and protection for itself. In a sense a tree is going into an wise energy cutting “hibernation” mode, conserving its energy, water and reducing its functions by dropping the leaves, and concentrate instead on leaving the core trunk and branches intact and still alive during the harsh, dark winter.

Trees are smart! Like in any ecosystem of course there is a symbiotic relationship at play here. Can you guess what it is? As the leaves drop onto the ground, they serve yet another purpose. The leaves surround space around the trunk where the roots grow beneath, and ever slightly, but significantly warms the soil and as the leaves decompose over time, give nutrition back to the soil from which it grows. As summer rolls around the trees uptake nutrition from the soil and power up the new leaves again, which synthesize the energy from the sun into chlorophyll, the green color that we see in leaves.

In summary, when trees lose their leaves they are simply conserving energy, warming themselves and compost their own nutritious leaves back into the soil from which they grow. This is a natural cycle that happens every winter, every year.

Making Use of the Fallen Leaves

Next time you see a pile of leaves that needs to be racked you can appreciate that the tree is actually doing some work for you and providing a layer of protection for itself. If you still don’t like those pesky leaves on your property, rake them up and use them in your own garden compost. Because leaves are full of carbon they are particularly helpful if the compost is lacking. If your compost bin has no dearth of carbon, perhaps your neighbor does, as it is a common issue that occurs when composting. -BEN TERRINGTON

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