November 10, 2017
Have you ever been walking through the woods and noticed a large, hollow tree with a full canopy? That tree, even though it looks dead, is still alive. Hollow trees can survive for years without falling over. They can do this because most of the living parts of a tree are just under the outer bark. These parts are called the phloem and the xylem.
The xylem transports food and water to the leaves, and the phloem transports nutrients from the leaves to the rest of the tree. The inside of the tree is made out of dead xylem, which is created by the cambium. The cambium is the living layer near the outside of the tree, which continuously creates new xylem each year, which is how the rings in a tree are made. The cambium also creates the phylum.
These trees get hollowed out for many different reasons. Most of the time the hollowness of a tree is due to either rot or animals digging it out. If it has been emptied out because the tree has rotted from the inside out, then it will die relatively quickly because it will continue to rot. If it had been dug out by a critter, everything that was not dug out would still be strong and the tree would be able to survive a while longer.