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. |
Glossary of Professional Terms:
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