The simple science behind the changing of Fall leaves

The leaves are changing, but there’s a lot more to this process than meets the eye.

Just like Mother Nature, the reason trees lose their leaves is both simple, but also complex at the same time.

We’ve seen the obvious consequences of trees retaining their leaves during winter conditions, right? Atlas anyone? So we know it’s an important process for deciduous trees.

It’s simple, once leaves stop helping the tree survive, they’re kicked out like a roommate that doesn’t help pay the bills.

“When the daylight starts to decrease, there’s a chemical that’s released which the tree says ‘okay we’re not going to need these leaves in the wintertime because its time for us to sleep its time for us to rest.” says Keith Wintersteen, a naturalist at Outdoor Campus West, “The tree sends out a chemical that cuts off the flow of nutrients to the leaves.”

But what if some years the change happens a little bit early? A little bit later?

Are the trees changing their mind? Is there something else at play here?

Something to remember about this whole process is that beautiful colors you see in the fall are actually there year round.

Wait. What?

“Everything has always been there,” Wintersteen continues, “It’s just that green is so overpowering and its so important that green takes control and it just overpowers everything else but now we’re peeling that back and see all the colors underneath.”

By far, daylight is the leading factor in starting the process. Otherwise we’d see huge swings between different years. The timeline in which that process finishes can vary, though.

Frost, dry sunny days, extra moisture, wind storms, the genetics of a given tree, all of these are factors that can shorten or lengthen so called “peak” season.

So what’s the advice of the experts? How long should you wait before you go see the leaves?

“Go! Every chance you get, get outside and enjoy what’s going on in nature, enjoy the turning color,” insists Wintersteen, “It’s better to see 100% of the 60% of the color than 0% of the 90% that have been blown off by the wind, just get outside and just enjoy it.”

Categories: Local News