2017-10-12 / Front Page

Goddard park ranger offers autumn science lesson


NEW VERNON TOWNSHIP — Goddard State Park Ranger Marisa Sprowles explains that the leaves of this tulip poplar at the park are turning yellow because of carotenoids in the leaves. NEW VERNON TOWNSHIP — Goddard State Park Ranger Marisa Sprowles explains that the leaves of this tulip poplar at the park are turning yellow because of carotenoids in the leaves. NEW VERNON TOWNSHIP — Most know how to appreciate fall’s splashes of foliage, but how many know where those colors come from?

It's fairly common knowledge that the chemical chlorophyll is what gives leaves their green color for much of the year, said Marisa Sprowles, a ranger at Goddard State Park. Chlorophyll helps trees turn sunlight into food, but as temperatures start to fall, trees begin to pull that stored sugar into their roots, and the chlorophyll starts to drain away.

The chemicals that cause most fall colors are there all along, just waiting for the chlorophyll to drain.

Carotenoids, which cause oranges, yellows and browns, are a constant, while anthocyanins — which can cause red, blue and purple — come about as the result of a chemical reaction between an increased amount of sugar in leaves and sunlight.


Sprowles Sprowles The best colors come with warmer days, cooler nights and just the right amount of rain. Too little rain, as local trees have seen recently, though, and trees begin to dry up.

“It’s a very fine balance,” Sprowles said.

Once they turn, why do they fall?

Trees shed their leaves because leaves are mostly water. Should a branch full of leaves freeze, there’s a good chance that branch will break.

Evergreens have adapted to that issue by developing a protective, waxy coating on their needles to prevent freezing.

That’s true for most needle trees, as wells as rhodenendors, which have waxy leaves that it holds onto most of, and also contain a chemical similar to antifreeze, which keeps them from freezing.

As for deciduous trees, oaks will be about the last to change.

To be sure, leaves aren’t the only things local trees will be dropping.

Oaks, for example, also drop acorns, which are an important fall food for animals such as squirrels and chipmunks that are trying to consume and store protein and fats to help them weather the winter.

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