The vascular cambium is in a cylinder around the stem between the main stem and the bark, and it initiates secondary growth. It is derived from both ground tissue and cells between the xylem and phloem of the primary vascular bundles. As the stem grows in diameter, phloem, xylem, and more cambium are produced. A girdled tree eventually dies because the vascular cambium is removed so water and nutrients cannot be transported. The periderm is composed of the cork, cork cambium, and phelloderm.
Cork cambium produces cork cells.
Suberin is contained in these cells. This substance makes cork impermeable to water. These cells are dead at maturity. The tissue of bark includes all of the tissues in a mature root or stem outside of the vascular cambium. Removing the periderm does not equal girdling the tree because no vascular tissue is removed and of itself this will not kill the tree.