ringbarking

Ringbarking, or girdling, is the process by which a continuous strip of bark is removed or damaged around the circumference of a tree stem. This interruption removes or damages the phloem tissue that transports sugars from the leaves to the roots, and can also affect the cambial layer that produces new xylem and phloem. If the girdle completely encircles the trunk, the flow of nutrients between the canopy and the root system is cut off, which can lead to the tree’s decline and eventual death.

Causes of ringbarking can be natural or human-induced. Animals such as beavers, deer, or rodents may strip bark on young or stressed trees. Mechanical damage from lawn equipment, construction activities, or road maintenance can also remove or injure bark. In some cases, trees are ringbarked intentionally for forestry, land management, or to create habitat features, though such practices are often regulated and vary by region.

The mechanism of injury centers on phloem transport and cambial activity. Removal of the bark around the trunk disrupts the movement of photosynthates from leaves to roots, weakening the tree over time. If the girdle is complete, the tree may die above the girdle while the root system deteriorates. Survival is more likely with partial girdling, intact cambial tissue elsewhere, and species-specific resilience.

Detection involves noticing a continuous ring of missing or damaged bark, exposed inner tissues, and signs of dieback above the girdle. In managed landscapes, prevention focuses on protecting trunks from damage with guards or fencing, avoiding mechanical injuries, and promptly addressing any bark loss. Dead or severely girdled trees may be removed if they pose safety risks.