PPL Environmental Preserves

Pinnacle Overlook at PPL Holtwood Preserve

There couldn’t have been a more beautiful day for a fall foliage hike at Pinnacle Overlook at PPL’s Holtwood Preserve on Saturday. It was one of the few perfect hiking days out of the year where it wasn’t too hot or too cold during a nice stroll through the woods. Before setting out on our adventure we took in the beautiful view of Lake Aldred, catching a few glimpses of vultures and several gulls flying over the lake in the distance.

At the overlook, we talked about why leaves change color in autumn. Scientists still don’t know all the details of this complicated process, but basically there are three main factors that influence autumn leaf color: pigments, the length of night, and weather. When the days grow shorter, and the nights get cooler and longer, it’s a cue for the tree to start preparing for winter. Photosynthesis will slow and eventually stop, thus seizing the production of chlorophyll, which produces the green color of leaves. This is all in an attempt to save energy in order to make it through the winter.

Fall Foliage at Pinnacle Overlook.

Once the chlorophyll pigment fades, you begin to see the carotenoid pigment that was always there, but masked by green. This pigment produces the yellow, oranges and browns you also see in carrots and bananas. The magnificent reds and purple hues you see in autumn are not always present, but are thought to be produced in fall as an additional sunscreen for the leaf that is susceptible to sun damage as chlorophyll fades. These reds are produced by anthocyanin pigments, which give color to familiar things such as cranberries, red apples, and grapes, among many others. The reason autumn colors can vary greatly among different regions, especially in PA, is because of the nice sunny days, and cool nights we have in northern PA. Leaves produce sugars on those sunny days, but the cold nights prevent the tree from pulling the glucose out of leaves for storage at night. This makes for the beautiful colors we see up north versus the more dull yellows and browns we see down south.

On our hike, we enjoyed the crunchy fall leaves at our feet and several interesting species, both native and invasive, along the way. Be sure to get outside and enjoy PPL’s thirty-nine miles of trails around Lake Aldred and the Susquehanna River at our Holtwood Preserve before the weather gets too cold! There are only a few more weeks of prime autumn leaf peeping left, and I plan to take advantage of them! I hope you do the same!

You have at least one more chance at the Fall Foliage Walk at Lake Wallenpaupack on Sat. Oct 20 at 10:00 am. For details see our calendar of events here.

-Sarah Hall, PPL Wallenpaupack