Long after many broad leaf trees have shed their leaves, beeches retain theirs until late winter or early spring.

by Ned Barnard & Pauline Gray

Take a winter walk in the Wissahickon woods. Among the bare tree trunks and branches you are likely to spot a few trees, often smaller ones, with papery dried leaves still clinging to their twigs. You will probably recognize them as beech trees by their smooth gray trunks.

Often smaller beech saplings with dangling dried leaves grow near larger beeches. These saplings may be clonal, all linked by a root network surrounding the largest tree.

Peter Wohlleben, a German forester and author of The Hidden Life of Trees, has popularized the idea that trees are social and communicate with each other through their roots and fungal networks.

Some dendrologists scoff at Wohlleben’s suggestions that trees are in any way conscious or purposeful, but there is certainly communication of a sort going on in our Wissahickon beech colonies. A big beech in a clonal group, with a crown bathed in bright canopy sunlight, pumps nutrients produced in its leaves down to the root network’s shadowed clonal samplings.

This arrangement eventually pays off.

When a big beech dies from injuries, fungal disease, or just old age, light streaming in from a new canopy opening stimulates one or more of the clonal trees to grow faster and replace the dying one. Thus a beech colony has a reproductive system that doesn’t rely on seeds landing in places with the just the right conditions to germinate, grow and escape hungry rodents.

There is no telling how old some of our Wissahickon forest American beech colonies are. I suspect that a few may have been around for hundreds of years or even a thousand years or more.

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