The American beech (Fagus grandifolia) is an
iconic tree,
the only beech species native to North America. Its smooth silver-gray bark makes it easy to identify, along with the characteristic leaf buds covered in copper-colored scales that resemble sharp thorns. On older trees the thick trunks begin to look like elephant legs, with saggy folds near the base and along branch intersections. The glossy dark green leaves are 4-5 long, oval shaped with wavy serrated margins and a pointy tip. Beeches are slow growing and long lived, providing nutrient rich beechnuts for wildlife, habitat and shelter for many organisms, medicinal uses of leaves, buds, and bark, and dense hardwood for furniture and other products.
Another clue to identifying a beech tree is marcescence: the ability of a tree to retain its dead leaves throughout winter. Scientists are not sure why beeches don’t fully shed their leaves in the fall: perhaps your students can offer theories! |
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Unfortunately, beech trees are in decline due to numerous diseases, including the most recent beech leaf disease (BLD) caused by an invasive nematode, a microscopic roundworm. Even the European beech (Fagus sylvatica), quite common in suburban landscapes with its copper beech variety, is in danger. |
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Outdoor Journal Activities |
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Beech leaves are terrific tactile objects with their parallel veins, waxy, leathery texture and rigid form. Collect a few from the ground and use them for leaf rubbings.
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Use a magnifying glass to observe the largest terminal leaf buds. Sketch them in your nature journal. Use fingernails to peel back the bud scales and observe plant tissue inside. Students will find a downy fuzz, tiny accordion folded leaves, and the beginnings of flowers, all packed tightly inside the bud! Tape the dissected bud into the journal and make notations.
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Hold a beech leaf up to the light – if you see bands of dark and light green in between the veins, you have found beech leaf disease. Observe the leaf canopy to investigate how much of the tree has been infected.
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If you can, cut a large twig (with leaf buds) from a beech tree and bring it indoors to force leaf buds to open. Put the twig in water next to bright light and observe it over time. The buds swell and grow longer before opening. Watch this time-lapse video!
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If you have access to microscopes and damaged beech leaves you can teach students to extract the nematodes for further analysis. Shred diseased leaves and place them in a shallow pan of water. Leave pan in a cool dark location for 1-2 days. The nematodes will move into the water which can then be used to create slides for use under the microscopes. Very important: Dispose of the infected water and shredded leaves by adding bleach to kill the organisms and bagging the leaves for disposal.
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