GLOSSARY OF TREE TERMS Aeration providing air to the soil to alleviate compaction and improve structure. Arboriculture the practice and study of the care of trees and other woody plants. Arborist a professional who possess the technical competence and experience related to training to provide for or supervise the management of trees and other woody plants in residential, commercial and public spaces. Bark the protective outer covering of branches and stems. Bifurcation the natural division of a branch or stem into two or more stems or parts. Blight any disease or disorder that kills young plant tissue. Bole the main trunk of a tree below the branches, usually used in reference to a tall tree whose first branch is high off the ground. Branch a stem arising from a larger stem or a subdominant stem. Branch union - the point where a branch originates from the trunk or another branch. Fork. Crotch. Bucking cutting of a tree trunk or log into shorter, manageable sections. Buttress roots roots at the trunk base that help support the tree and equalize mechanical stress. Canker localized diseased area on stems, roots and branches. Often shrunken and discolored. Canopy collective branches and foliage of a tree or a group of trees crowns. Cavity open or closed hollow within a tree stem, usually associated with decay. Chipper equipment used to reduce tree debris to wood chips. Circling roots roots that grow in a circular pattern when a plant is confined in a container longer than necessary. If not corrected, a circling root pattern will prevent a tree from establi shing well when transplanted creating future problems, such as blow-ever or strangulation. Clearance amount of open space between a tree and another object or the ground. Often used in reference to the distance between trees and utility lines. Conservation planned management of natural resources to prevent exploitation, destruction or neglect.
Cracks narrow breaks or fissures in stems or branches. If sever, may result in tree branch failure. Crook abrupt bend in a branch or trunk. Crown upper part of a tree, measured from the lowest branch, including all branches and foliage. Crown cleaning in pruning, the selective removal of dead. Dying, diseased, and broken branches from the tree crown. Crown raising the selective removal of lower limbs from a tree crown to provide clearance. Raising. Lifting. Crown Reduction method of reducing the height and/or spread of a tree crown by making appropriate pruning cuts. Reduction. Crown thinning the selective removal of live branches to reduce crown density when pruning Cycle in utility and municipal arboriculture, the length of time between each maintenance pruning for a given circuit or geographic area. Pruning cycle. Cycle Buster fast-growing trees that need to be pruned more frequently than the set pruning cycle. Deadwooding removing dead and dying branches from a tree. Crown cleaning. Dieback condition in which the branches in the tree crown die from the tips towards the center. Directional Pruning providing clearance by pruning branches that could significantly affect the integrity of utility facilities or other structures, and leaving in place branches that could have no or little effect. Dormancy period of naturally reduced physiological activity in the organs of a plant with the potential for reactivation of growth. Evergreen tree or other plant that does not shed all of its foliage annual. Exudation oozing from pores or breaks in cell membranes. Face cut a notch used to help control the directional fall of a tree or branches being removed. Failure potential the professional assessment of the likelihood for a tree or tree part to fail within a defined period of time. Felling dropping or cutting down a tree. Glossary of Tree Terms Pg. 2
Flagging (1) symptom in which leaves on a branch wilt and may ultimately turn brown without falling. (2) growth of trees growing in strong winds, characterized by the branches growing towards the downwind side. (3) colored tape used to mark trees or surveying points. Frost crack vertical split in the wood of a tree, generally near the base of the bole, caused by internal stresses and low temperatures. Gall abnormal swelling of plant tissues caused by gall wasps, mites and various insets and less commonly fungi or bacteria. Girdling restriction or destruction of the vascular system within a root, stem or branch that causes an inhibition of the flow of water and photosynthesis. Girdling root root that encircles all or part of the trunk of a tree or other roots and constricts the vascular systems and growth. Greenhouse effect rise in temperature cause by gases or materials suspended in the atmosphere that trap energy from the sun. Gummosis exudation of sap or gum from the bark, often in response to disease or insect damage. Hanger a broken or cut branch hanging in a tree. Hardened off plant tissue that is acclimated to the cold or a new environment. Hardwood wood of an angiosperm tree as distinguished from that of a conifer; broad-leaved tree. Hazard - a tree or tree part that has a high likelihood of failure and causing damage or injury. Hazard reduction pruning type of pruning to remove dead, severely decayed, split or unsafe branches. Heading cutting a branch back to buds, stubs or lateral branches not large enough to meet a structural objective. Included bark bark that becomes embedded in a crotch (union) between branches and trunk or two dominant stems. It is known to cause a weak structure. Kerf the space between a saw s cut in a log. Kerf cuts cuts made to prevent tearing from a branch or trunk section being removed. Landing zone predetermined area where cut tree branches or wood sections will be dropped or lowered. Glossary of Tree Terms Pg. 3
Lateral a secondary branch or root. Leaf - the primary, photosynthetic organ of a plant that is connected to a stem. Leaf blotch diseased areas on foliage. Leaf spot. Lifting the act of raising a tree s crown when pruning. Lion tailing poor pruning practice in which an excessive number of branches are thinned from the inside and lower part of specific limbs of a tree crown, leaving mostly terminal foliage. Results in poor branch taper, poor wind load distribution, and a higher risk of branch failure. Mature height maximum height that a tree is likely to reach if all conditions are favorable. Minimum approach distance closest distance that a tree worker, tool or piece of equipment may go near overhead electrical components. Mitigation reducing, alleviating, or minimizing the risk of harm. Mortality spiral a sequence of stressful conditions that cause the decline and eventual death of a tree. Mulch Usually composed of chipped ground or shredded material such as bark. Mulch placed on the soil surface to reduce weed growth, retain moisture in the soil, reduce erosion, and moderate temperatures. Node slightly enlarged portion on a stem where leaves and buds grow from. Notch a wedge cut made for felling a tree. Outriggers a projecting structure used to stabilize any vehicle that supports elevated or outstretched loads (i.e. a crane). Peavey a lever with an adjustable hook and sharp spike used for handling and rolling l ogs. Permanent branches structural pruning where branches which are left in place for the initial framework for a tree. Pruning removing a branch or root to achieve a specific objective. Raising selective pruning to give vertical clearance. Crown raising. Reduction pruning to decrease height or the spread of a tree. Glossary of Tree Terms Pg. 4
Reduction cut pruning the length of a branch back to a lateral branch large enough to assume apical dominance. Removal cut to remove a branch at its point of origin. Restoration pruning a tree to improve its structure, form or appearance due to being improperly trimmed or damaged. Rigging to direct the descent of cut material or to handle a heavy load. Root plate large structural, small roots and soil near the base of a tree s trunk which are largely responsible for holding the tree erect. Root rot decay that starts in a tree s root system. Scorch the browning and shriveling of foliage. Sinker roots Roots which grow downward providing anchorage and taking up water. They are especially useful during a drought. Skeletonized damage caused to leaves by insects who s feeding creates a loss of tissue between the leaf veins. Spear cut quickly cutting an upright branch so that it drops upright. Split an open crack in a tree s trunk or branch. Structural pruning pruning to establish a strong system of branches. Stub part of a branch that remains after a cut or breakage. Stump base of tree that remains when the tree is felled. Stump grinder a piece of equipment used to remove tree stumps by grinding away the solid wood. Wood shavings will be left upon completion. Sucker a shoot that arises from the root. Thinning Selective removal of live branches to provide light, air penetration through or lighten the weight for remaining branches. Through-pruning Pruning that removes the branches from the center of the tree to provide clearance for utility lines. Glossary of Tree Terms Pg. 5
Topping an inappropriate pruning technique that cuts back a tree to the crown limit to reduce the tree s size. Vista pruning pruning to enable to view from a predetermined spot. Windthrow tree failure caused when a tree is uprooted by wind. Glossary of Tree Terms Pg. 6