Tree Terminology and Glossary

Arborist - A professional who possesses the technical competence through experience and related training to provide for or supervise the management of trees and other woody plants in the residential, commercial, and public landscape

Branch Collar - Trunk tissue that forms around the base of a branch between the main stem and the branch or a branch and a lateral; as a branch ceases in vigor or begins to die, the branch collar becomes more pronounced.

Certified Arborist - An individual with a minimum of 3 years of experience in the Arboricultural field, and someone who has passed a 10 part exam from the ISA (International Society of Arboricultural) and a professional who possesses the technical competence through experience and related training to provide for (or supervises the management of) trees and other woody plants in the residential, commercial, and public landscape.

Crown - The leaves and branches of a tree or shrub: the upper portion of a tree from the lowest branch on the trunk to the top of the tree

Crown Cleaning - The removal of dead, dying, diseased, crowded, weakly attached, low-vigor branches, and water sprouts from a tree’s crown

Crown Raising - The removal of the lower branches of a tree in order to provide clearance or view

Crown Thinning - The selective removal of branches to increase light penetration and air movement, and to reduce weight

Deadwooding - Cutting the dead and dying limbs from the tree

Decay - Degradation of woody tissue caused by biological organisms

Girdling Roots - Roots located above or below ground whose circular growth around the base of the trunk or over individual roots applies pressure to the bark areas, ultimately restricting sap flow and trunk/root growth, frequently resulting in reduced vitality or stability of the plant

Lateral - A branch or twig growing from a parent branch or stem

Leader - A dormant upright stem, usually the main trunk, there can be several leaders in one tree

Leaves - The most important site of photosynthesis

Parent branch or stem - The tree trunk or a large limb from which lateral branches grow

Plant Health Care (PHC) - To maintain or improve the landscape’s appearance, vitality and in the case of trees - safety, using the most cost–effective and environmentally sensitive practices and treatments available. PHC involves monitoring, using preventative treatments, and adopting a strong commitment to work closely with the tree owner; For more information please see our PHC section.

Pruning - Removal of plant parts

Removal - The removal of an unwanted or dead tree or shrub from the landscape

Roots - Structural support for the tree: Absorption of mineral nutrients and water; storage of "food"

Stump Grinding - Grinding the remainder of a stump 6”-12” below surface level, leaving chips from stump unless requested to haul the chips/mulch from the site

Topping- The improper cutting of a trees crown. For more information please see our topping section

Trunk/Limbs/Stems - Structural support for the top portion of the tree and storage of “food”; they also house the transport system that carries water, nutrients, food, and other plant materials between the roots and leaves

Wounding - The opening that is created any time the tree’s protective bark covering is penetrated, cut, or removed, injuring or destroying living tissue. Pruning a live branch creates a wound, even when the cut is properly made.