Because phloem tubes sit on the outside of the xylem, and just under the bark, trees and other woody plants can easily be killed by stripping away the bark in a ring on the trunk or main stem. This process is known as girdling or bark ringing.
Incomplete girdling (i.e., leaving about one-third of the bark intact) can be used to control a plant's growth. It can curb excessive leafy growth and help promote flowering and fruiting. It is a very useful process for unproductive fruit trees, with the exception of stone fruit.
Mice, voles, and rabbits can often girdle trees as they feed on its nutritious, sappy bark -- where these animals are a problem, trees should be protected with some kind of netting or other physical barrier around the main stem.
