Fading Fall Colors Reveal Vermont’s Oaks

Amidst all of Vermont’s beautiful fall foliage, oaks are not often mentioned. They don’t have the vivid fire red of red maple leaves or the shining gold of sugar maple or aspen leaves. Viewed from afar, red oak, Vermont’s most common oak species, is somewhat underwhelming in terms of fall color. Up close, on the other hand, the color of individual leaves can be amazing, but the colors run together from a distance.

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I couldn’t believe that leaf was real! But it was… we saved it and pressed it and while the colors have muted some they are still amazing (the leaf is at least seven inches long).

There is something else special about oak foliage though… oaks, or at least red oak, change color later than other tree species and keep their leaves longer. (Beech, a relative of oak, also doesn’t drop its leaves readily but they are distinguishable from oak from afar).

During this time of year, the red oaks of Montpelier’s Hubbard Park become readily apparent as the leaves blow away from the maples and birches.

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Excuse the silly filter… the light greens and yellows in the background are all oaks, with dark green pines beyond.

Here’s an even more extreme example – look to the ridge in the distance on the right for an area of olive-green…

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This oak grove is visible from the top of Mount Hunger, looking west. This places the oaks on the top and slope of a southwest-facing ridge. Red oak in Vermont tends to favor those sorts of areas because it’s near the limit of its cold tolerance and also likes drier areas – south and southwest facing slopes catch lots of sun and create microclimates that favor oaks.

Looking back at Mount Hunger from the west you can see the oaks, just barely, on the far right of the photo below. You can also see how elevation affects foliage, with the trees higher up having lost their leaves already. The highest areas support spruce and fir which are of course evergreen and thus do not lose their needles.

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These oaks happen to extend down to the trail up the mountain so we also saw some up close…

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This tapestry of tree species and their corresponding colors is useful as well as beautiful. Oaks are important to track for a variety of reasons. They are important to many species of wildlife, from bears to squirrels. They tolerate harsh conditions and hold the soils. They are indicators of various changes… increases in temperature may increase their range, but increases in precipitation happening at the same time may offset that. Changes in land use may favor or discourage them, and it seems all the tree species in Vermont are vulnerable to one sort of disease or another. During both the summer and the winter the oaks blend in with the other hardwood tree species, but during October and early November, they jump out to be seen by anyone who is looking.

When we are really lucky, someone takes aerial photos during the fall, and we can map the distributions of oak in very fine detail.

In this air photo you can see the oaks as green blobs, with ‘pokey’ green conifers scattered about and colorful maples, birches, and perhaps hickory also visible.

Here’s an iNaturalist map of where red oak has been reported. It occurs in about half the state, in the Champlain Valley and Connecticut River Valley, and the major rivers that bisect the Green Mountains but is largely absent from the higher mountains and most of the northeastern part of the state. If you’d like to contribute to this map, now is a great time to do so as the oaks are still very visible. There are other oak species that can be found in Vermont too, including white oak, burr oak, and swamp white oak, but these are much more limited in range. All of these seem to keep their leaves longer than other hardwoods, so they should be increasingly visible in the warmer areas where they occur and where other trees drop their leaves later.

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