restriction or destruction of the vascular xylem within a root. stem. or branch that causes inhibition of the flow of water and photosynthates in the phloem.
Girdling, also called ring-barking is the complete removal of a strip of bark (consisting of cork cambium or "phellogen", phloem, cambium and sometimes going into the xylem) from around the entire circumference of either a branch or trunk of a woody plant. Girdling results in the death of the area above the girdle over time. A branch completely girdled will fail and when the main trunk of a tree is girdled, the entire tree will die, if it cannot regrow from above to bridge the wound. Animals such as rodents, will girdle trees by feeding on outer bark often during winter under snow. Human practices of girdling including forestry, horticulture, and vandalism. Foresters use the practice of girdling to thin forests. Girdling can also be caused by herbivorous mammals feeding on plant bark and by birds and insects, both of which can effectively girdle a tree by boring rows of adjacent holes.