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Glossary of Professional Terms:
Absorbing roots small and fibrous, they take up water and nutrients; usually found at shallow depth in the root zone.
Absorption taking up.
Access route roadway for entering and leaving a construction zone.
Aeration drilling holes or pumping air into root zones to overcome compaction or improve water movement.
ANSI A300 American National Standards Institute; standards of treatment for tree care practices.
ANSI Z133.1 American National Standards Institute; standards of safety for tree care practices.
Antitranspirant chemical applied to plants to reduce water loss through leaves and stems.
Anvil pruner tool with straight blade that presses onto a flat surface; not recommended for tree pruning.
Arboriculture science of growth and development of trees, and tree care practices.
Backfill soil and any amendments used to cover roots during transplanting.
Balled and burlapped trees grown in field soil and harvested manually or mechanically; wrapped in burlap with twine, and may have wire cage for larger trees.
Bare root trees grown in field soil but shaken or rinsed to remove soil when harvested; handled during dormancy. Smaller specimens usually, but survival of larger root masses is possible with hydrogel products.
Bark outer layer of stems and trunks; protective tissue.
Barrier fenced or otherwise designated boundary of root protection zone during construction.
Branch stem originating from another, larger stem.
Branch bark ridge protruding bark at the top of the junction (crotch) of two branches; continues downward from crotch.
Branch collar junction (overlap) of tissues of two branches or branch and trunk.
Bud small dormant apical or lateral meristem; may be foliar or floral tissue; undeveloped flower or stem.
Buttress root large woody root extending trunk into the soil; part of root flare.
Bypass pruner tool with curved lower and cutting blades that slide past each other to operate.
Cambium layer of lateral meristematic cells; produces phloem and xylem tissue.
Canopy branch and leaf portion of tree (also called crown).
Carbohydrate energy-storage compound produced by photosynthesis.
Cavity open wound or hollow in trunk of tree; result of decay.
Central leader main growing terminal stem of a tree.
Certified arborist professional tree service provider; certification regulated and maintained with International Society of Arboriculture. Certified Arborist: an individual who has passed the certification examination sponsored by the International Society of Arboriculture and who maintains a current certification.
Codominant stems two equally competing terminal branches.
Compaction squeezing of soil that results in loss of pore spaces.
Containerized trees grown in pots in a nursery since propagation, usually in a soil less mix; may have been stepped-up numerous times before sales.
Crotch top of the union of two branches or of branch and trunk.
Crown aboveground portion of tree.
Crown cleaning removal of watersprouts, suckers, dead, dying, diseased, deformed and damaged branches.
Crown reduction alternative to topping; reducing canopy by appropriate pruning techniques.
Crown restoration technique to restore growth habit of topped or damaged tree.
Decay deterioration of woody tissue by diseases.
Deciduous trees that drop their leaves in winter.
Desiccation extreme drying out.
Dieback condition of death of many terminal branches.
Dormant at rest, or in a state of reduced activity.
Drip line boundary of the canopy.
Drop cut second cut in 3-cut process of removing a branch.
Drop zone area where cut branches may fall during pruning.
Evergreen trees that keep their leaves or needles year-round.
Extension pruner hook and blade bypass pruning tool on telescoping handle, operated by rope.
Fail a tree or branch breaks or falls.
Flush cut improper pruning technique; removes branch collar and damages trunk.
Girdling root root growing around part of the trunk, restricting its expansion.
Guying stabilizing a tree with ropes or wires attached to ground staubs.
Hand pruners tool for one-handed cutting of smaller stems.
Hardened off gradually introduced to a new environment.
Hardiness ability to withstand cold or warm temperatures.
Hardiness zone sections of the country designated by expected range of low temperature.
Hazard potential likelihood of failure and damage posed by a tree.
Heading back pruning shoots back one-half to one-third to buds or twigs with potential for growth.
Heartwood inner wood (nonfunctioning xylem) that gives strength to the trunk.
Horizon layer of soil in the profile.
Included bark bark tissue lodged in the crotch of two branches or branch and trunk indicating weak attachment.
Invasive species- an alien species whose introduction does or is likely to cause economic or environmental harm or harm to human health, as defined by the Department of Agriculture.
Lateral side branch or smaller twig of a limb.
Lateral bud vegetative bud on side of a branch.
Lateral root branching root beyond buttress root zone.
Leader primary terminal stem of a tree or scaffold branch.
Liability legal responsibility; generally associated with probable cost to repair damage.
Lopper tool for two-handed cutting of larger stems.
Lowest permanent branch lowest limb that will remain in tree canopy.
Main branches those that make up the canopy of the tree (scaffold branches).
Mature height tallest expected growth of a tree.
Mature tree has reached approximately 75% of its full canopy growth.
Mechanical trimming- cutting of plant parts by any power-drive method other than chainsaw or boom-axe.
Meristem tissue capable of dividing to form new cells.
Multiple leaders codominant stems competing for central growth of tree.
Mycorrhizae fungus root; symbiotic combination of fungus and root tissue.
Native - a species that historically occurred in a physiographic region of Virginia.
Natural target pruning technique of removing branch that protects the branch collar; 3-cut process.
Node point of attachment of leaves and axillary buds.
Permanent branch branch that will remain on tree; initial scaffold framework.
pH measurement of acidity level of soil.
Phloem food-conducting tissue of tree just outside of cambium.
Photosynthesis food-making process of green plants.
Planting specifications detailed diagrams and statements specifying techniques for installing trees.
Pole pruner long-handled pruner to reach into canopy without a ladder.
Pole saw long handled tool with tree saw on the end.
Pollarding specific pruning technique for height restriction of trees.
Pruning cutting away undesirable parts of a tree.
Radial trenching technique for improving soil aeration in root zones; trench radiates from trunk.
Raising removing lower branches to provide clearance.
Reduction pruning to reduce height and/or spread of canopy.
Respiration cellular process releasing energy from stored foods.
Restoration pruning to recover shape and strength of damaged canopies.
Riparian Buffer- a band of trees, shrubs, or grasses that border a body of water.
Root ball remaining root and soil after tree is field-harvested.
Root flare base of trunk that swells out to become buttress roots entering the soil; root collar.
Root pruning cut or remove any circling or girdling roots; cutting roots to increase density of root mass.
Scabbard sheath for tree saw.
Scaffold limb permanent, main branch of the canopy. Ample vertical and radial spacing improves tree structure.
Sinker roots deep-growing roots providing tree stability.
Site considerations factors to take into account when determining what trees to select for the location.
Soil amendment material mixed with soil to adjust physical or chemical status.
Soil analysis determination of pH and mineral status (P and K usually) of soil.
Soil compaction pressing of soil that removes pores, eliminating water- and air-holding capacity.
Staking using stakes to support newly planted trees.
Standards specifications for tree installation, maintenance and/or pruning.
Stress any of a group of factors that has a negative effect on tree health.
Structural defect any flaw in a trunk, branch or root that weakens the tree, possibly leading to failure.
Structural pruning pruning to develop a sound scaffold branch system in a tree.
Subordinate prune a branch to retard its growth rate compared to competing branches.
Sucker shoot originating from a root or lower trunk.
Sunscald bark damage by excess sunlight and heat.
Taper decrease in diameter of trunk and branches from the base toward the tip.
Temporary branches shoots that remain during training of young trees, to be removed as tree matures.
Terminal bud bud at the apex of a stem.
Tree- woody vegetation two inches or greater in diameter to be measured at ground level.
Tree protection zone area of tree roots to be designated by fencing to prohibit access during construction activities. Minimum 8-foot radius, or usually 1-foot radius per inch diameter at breast height.
Thinning selective pruning of entire stems to increase air or light penetration to canopy or to decrease branch weight.
Topping non-professional pruning technique; non-selective canopy reduction, often destructive to tree.
Transpiration loss of water vapor from pores in leaves; cooling and nutrient transport process.
Transplant install new tree into the landscape.
Transplant shock environmental stress (moisture, heat) after installation due causing wilting or leaf drop.
Tree well wall and root aeration system around tree and root zone when soil grade is raised.
Tree wrap temporary material to protect trunk of recently transplanted trees.
Trunk base stem of tree that supports canopy.
Tunneling boring a hole under root zones; alternative to trenching to protect roots.
Turgid adequate water pressure in tissues.
Undercut first of 3-cut process in natural target pruning. Prevents bark tearing.
Vertical mulching drilling vertical holes in root zone and filling with porous material to improve aeration and water penetration.
Water sprout fast-growing, usually vertical shoot from a lateral branch.
Weak crotch narrow angle connecting two branches or branch and trunk; often with included bark.
Wilt loss of turgidity, drooping of leaves.
Wind throw toppling failure due to high winds.
Wire basket external supporting cage for large B&B root masses.
Wound dressing not recommended; compound for covering cut branch ends.
Xylem water-conducting tissue produced by cambium; becomes wood and provides structural support.
Text condensed and abridged from: Lilly, S. 2001. Arborists certification study guide. International Society of Arboriculture; and An Illustrated Guide to Pruning, 2cd edition, by Gilman. Copyright 2002. Reprinted with permission of Delmar Learning, a division of Thomson Learning. Fax 800-730-2215.
Purpose Right Tree / Right Place Selecting Trees Transplanting Trees Mulching & Staking Summary Diagram Pruning Trees Topping Hurts! Protecting Trees Tree Root Myths Pine Bark Beetles Live Christmas Trees Glossary List of Figures List of Video Vignettes Related Links Bibliography