Tamarack and bald cypress drop needles to deliver oxygen to bog roots

Evidence

Tamaracks are one of the two conifers in North America (the other is the bald cypress of the southern swamps) that lose their leaves in winter. Both apparently do so because of the extreme lack of oxygen in the decaying matter and mud found in the bogs and swamps about their roots. Such trees must bring oxygen down to their roots from the leaves, and the leaves are only able to do this during the warm season of the year. — Vinson Brown, Reading the Woods, 858

Categorization

• DEFINE: Why tamarack (a common Minnesota bog tree) is deciduous — mechanical explanation for identification.
• XREF: connects to: Pond lily leaves relay surface oxygen through air-filled cells to buried roots — Robin Wall Kimmerer, Braiding Sweetgrass: Indigenous Wisdom,…, 344; Oxygen flows from young lily leaves to old through shared air networks — Robin Wall Kimmerer, Braiding Sweetgrass: Indigenous Wisdom,…, 350