Created By: Cornell Lab of Ornithology
Prop roots are a fascinating natural phenomena. If you look toward the base of this black birch tree trunk, you’ll notice that the trunk is not connected to the ground. The intertwining prop roots lift the tree above the surface of the soil and allow you to see them above ground. How does this happen? When seeds from other trees land in a decomposing tree trunk, the seedlings begin to grow upward from the trunk. As time passes, the trunk slowly decomposes away. By then the seed’s roots have already reached below the depth of the trunk and made its way into the soil. When the original dead tree trunk decomposes completely, prop roots are exposed. This phenomenon is not special to black birch alone, and can happen in a variety of other trees subjected to the same conditions as well.
This point of interest is part of the tour: Sapsucker Woods Through the Seasons: Fall/Winter