Tree Roots
Large Douglas-fir tree roots can be seen on the left between Petrified Garden and the Marble Ceiling. Fungi and small insects can usually be seen on or around the root.
Geology
Room Development
The Douglas-fir root may extend down into the cave via a sinkhole—a karst feature, which is a collapse of rock that creates a shallow depression at the surface (Palmer 413).
Ecology
Plants
The roots are the deepest known Douglas-fir tree roots in the world, going down about 40 feet. The roots are no longer alive, since the tree was cut down in the 1960s to prevent injuries to people and damages to the Monument’s historic structures (Roth 10). Although the roots are no longer living, the bigger ones are not readily decaying, likely due to their lack of contact with the soil and the narrow range of temperature and humidity changes in the cave that prevent cracking in the wood.
Fungi
Growing on the root are purple mycena mushrooms (Mycena purpureofusca). They usually sprout in the spring, because the fungi’s main cue to fruit likely comes when the cave begins to dry out (Roth 10).
Animals
Often springtails and at times other cave creatures, such as ants and endemic millipedes, can be found on or around the Douglas-fir tree root. These creatures capitalize on the food sources created by the root, bacteria and fungi (Roth 10).
The springtail shown at the right is enlarged to show detail. In fact, the springtail is about the size of the dot below.
References
Palmer, Arthur. “Glossary.” Cave Geology. Dayton: Cave Books, 2007. 408-414.
Roth, John. “Interpretive Manual for the Monument’s Showcave”. Cave Junction: Oregon Caves National Monument, 2011. 10.