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Nature Notebook – Silver Maple Trees

To walk along our wetland trails one must step carefully or face tripping over the surface roots of silver maple trees, so named for the silvery underside of their leaves.

This tree is more at home in the moist soils of flood plains and stream banks than with its “cousins” in the drier, upland ecosystems. Up there, faster growing trees shade it out but, down below, silver maples can reign supreme because they can survive long periods in water-saturated soils.

Those tripping-hazard roots are the most obvious adaptation that facilitates this superiority. A tree’s roots need oxygen in order to utilize the sugar produced by photosynthesis. Waterlogged soil is rather deficient in oxygen. Silver maples can develop new root systems that sit on top of the soil’s surface allowing the roots to absorb oxygen from the atmosphere, instead of the soil. Silver maple trees also have large lenticels which are tiny openings that enlarge in response to prolonged soil saturation to allow oxygen to move into the tree.