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A Year in the Life of Pimmit Run: The Colors of Fall

Updated: Nov 27

Following almost a year of looking down at the forest floor, in November, the place to look is up. Leaves are now the stars of the stream valley scene, at least until they fall. And during their short time of glory, they are highlighted by the low hanging sun and brilliant blue sky.

It's time to look up

Leaves in the Stream

Before we turn to the fall foliage on the trees and shrubs in the stream valley, let's think about those leaves when they do fall into the stream. Wet, rotting, leaves are a stream's best friend. They release tannin and dissolved organic matter that can turn the water brown or even black in spots, but which feed the beneficial stream organisms. This usually occurs right around Thanksgiving when the rest of us are eating turkey. Yay leaves! Nature's ultimate compost and food.

These leaves are like Thanksgiving for the critters in the stream

The Glory of the Trees

Along the floodplain, the Red Maples (Acer rubrum) are glowing...yellow? But at least their red stems do stand out against the foliage. Red Maple is one of the first native trees to turn color, and the leaves can change to a variety of colors from yellow to deep red. All of the Red Maples I came across this year in the floodplain had yellow fall leaves. The mark of the species, I guess.

The Red Maples are yellow

A walk in the Oak Beech - Heath Forest right now is like being enveloped in a cloak of copper. This is due to the stands of the young American Beech (Fagus grandifolia) trees, with their golden leaves that are among the last to fall and often hold on all winter. The Beech tree is a prolific regenerator which grows in clusters among the tall oaks. It thrives in the shade of the taller canopy trees, waiting to take over as the next successional wave when the time comes.

Beeches waiting for the canopy to open up

The Flowering Dogwood (Cornus Florida) stands out in the understory layer along the stream edge, with its rounded red leaves. In the wild, it seems to grow in lanky, sprawling lengths and its leaves bob like little red balloons.

Lanky dogwoods twisting this way and that

The leaves of the canopy trees are too high to photograph close up! But I found lots of floodplain canopy tree saplings displaying vibrant tones. The Oaks are on the top row below: Red Oak (Quercus rubrum) and White Oak (Quercus alba) form a high carpet on the forest floor. The Red Oak leaves have the characteristic pointed tips and, true to its name, deep red fall color, while the White Oak leaves are rounded and a bit more muted. On the bottom row we have Tulip Poplar (Liriodendron tulipifera) and Sassafras (Sassafras albidum). Most of the Tulip Poplar leaves turned yellow a while ago and they have mostly fallen by now. Sassafras is famous for its brilliant autumn display with leaves that turn yellow, deep orange, scarlet and purple. These are showing a hint of what is to come.

Sometimes the tree trunks steal the fall show. The American Hornbeam (Carpinus caroliniana) gets greater accolades for its sinewy trunk, which has the characteristic muscle-like ridges that really pop when highlighted by the fall sunrays.

Nice muscle tone!

Shrubs Also Glow

They may be shorter, but they can be just as showy -- the shrubs of the Oak Beech - Heath Forest and floodplain floor. On the left, Mapleleaf Viburnum (Viburnum acerifolium) boasts an ephemeral, muted, shade of red. On the right, the yellow fall foliage of the Spicebush (Lindera Benzoin) gives away its identify, just like its tiny yellow early spring blossoms.

The Leaves on the Ground

The leaves on the ground not only nourish the soil and provide shelter, they also frame new winter growth. I did check out what was happening along the forest floor. And I found not a lot in terms of the perennials of summer and fall! But I did see some very welcome signs of winter, including Spotted Wintergreen (Chimaphila maculata) and Cranefly Orchid (Tipularia discolor), pictured below on the left and right, respectively.

And that is it. We are nearing the end of a full year along the stream valley. One thing is certain - the closer one looks, the more one sees.



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