Girdling is a procedure to kill unwanted tress by cutting a groove into the bark of the tree. the groove must completely encircle the trunk and should penetrate into the wood to a depth of at least -inch on small trees, and 1- inches on larger trees. why does this procedure cause tree death?

Girdling is the removal of a strip of bark from the entire circumference of a tree trunk. This causes the death of the tree because phloem tubes are located outside the xylem in most plants. Girdling destroys the connection of the phloem tubes from the upper tree to the tree roots, and results in nutrients not reaching the roots, and the tree dying.

More; less is the correct answer