| *under construction* |
Please email us @ info@treestuff.com if you have a term you'd like to see here. |
| 12-strand rope |
For arborist ropes, a braided rope consisting of 12 strands. Most are coreless. There are two types of 12-strand construction: a tight braid that isn't easily spliceable, used for climbing and rigging lines; and a loose, easily spliceable braid, commonly used for slings. |
| 16-strand rope |
For arborist ropes, a braided rope that has a 16-strand, load bearing cover and a filler core that isn't significant in load carrying. |
| 24-strand rope |
For arborist ropes, a braided rope that has a 24-strand cover and is available in double-braided or kernmantle construction. |
| 3-strand rope |
Rope construction in which three strands are twisted together in a spiral pattern. |
| 7-strand, common-grade cable |
Steel-cable construction in which seven strands are twisted together in a spiral pattern. Used to add supplemental structural support to trees. Terminated by wrapping onto itself. |
| abscission |
Leaf or fruit drop induced by hormonal changes. |
| access line |
(1) Second climbing line hung in a tree in case it is needed to reach a victim in an emergency. (2) Climbing line installed in a tree to gain access to, but not used to work, the tree. |
| action |
Pertaining to carabiners and snaps, the number of distinct motions for the gate to be opened. A nonlocking carabiner is single action, requiring one movement for the gate to be opened. |
| adventitious |
Arising from parts of the root or stem and having no connection to apical meristems. |
| aerial device (aerial lift device) |
Truck with booms and a bucket for elevating a worker to the proximity of a tree's crown. |
| aerial rescue |
Method of bringing an injured worker down from a tree or aerial lift device. |
| alkaline |
Having a pH greater than 7.0. Contrast with acid. |
| amon-eye nut |
Specialized nut used in cabling trees that has a large eye for attaching a cable to a threaded rod. |
| anchor |
(1) In cabling, hardware to which support cable is affixed. (2) In rigging, the point at which the rigging system is secured or where friction is controlled. |
| anchor hitch |
Knot commonly used to attach a line to a piece of hardware. Anchor bend.
Learn how to tie an anchor hitch. |
| ANSI |
Acronym for American National Standards Institute. |
| ANSI A300 |
In the US, industry-developed national consensus standards of practice for tree care. |
| ANSI Z133.1 |
In the US, industry-developed national consensus safety standards of practice for tree care. |
| anthracnose |
Group of fungal diseases of trees that affect the leaves, stems, flowers, or fruit, causing spotting, blotching, or necrosis. |
| antitransprant |
Substance applied to the foliage of plants to reduce water loss (transpiration). |
| anvil-type pruning tool |
Hand pruning tool with a sharps, straight blade that cuts against a flat metal surface. Cuts across fibers and may crush adjacent fibers. Intended for cutting single, small-diameter stems. Also called hand pruners or hand snips. |
| aphid |
Group of sap-sucking insects of the Hemiptera order. |
| arboriculture |
Practice and study of the care of trees and other woody plants in the landscape. |
| arborist |
Professional who possesses the technical competence gained through experience and related training to provide for or supervise the management of trees and other woody plants in residential, commerical, and public landscapes. |
| arborist block |
Heavy-duty pulley with an integrated connection point (bushing for attaching a rope sling), a rotation sheaves for the ropes, and extended cheekplates. Used in tree rigging operations. |
| ascender |
Piece of gear that enables a climber to ascend a rope. Attached to the rope, it will grip in one direction (down) and slide in the other (up). Contrast with descender. |
| auger |
Tool that bores holes in wood or other materials while carrying cuttings away from the bored hole. Fitted with a cross handle for hand use. |
| auger bit |
Tool that bores holes in wood or other materials while carrying cuttings away from the bored hole. Fitted with a hex, round square, or threaded shank for insertion into a power drill or driver. |
| back cut |
Cut made on a tree trunk or branch, opposite from the and toward the notch, face cut, or undercut, to complete felling or branch removal. Contrast with bore cut. |
| bacteria |
Single-celled organisms having a cell wall but no organized nucleus. A few species are plant pathogens. |
| bactericides |
Pesticides that are used to kill or inhibit bactera in plants or soil. |
| balancer |
Rigging sling(s), usually with at least one spliced eye and a Prusik to position the load line. Used to rig a limb in a balanced configuration. |
| barber chair |
Dangerous condition created when a tree or branch splits upward vertically from the back cut, slab up. |
| bark |
Protective outer covering of branches and stems that arises from the cork cambium. |
| basal bark application |
Application of herbicides, usually mixed with penetrating oil, to the lowest 12 to 18 inches (30 to 45 centimeters) of the main stems(s) of unwanted vegetation. |
| bearing |
Device, often relying on balls or rollers, to reduce friction between mechanical parts such as a wheel or a pulley sheave and an axle or a shaft and case connecting rod. Contrast with bushing. |
| becket |
An auxiliary attachment point on a block or pulley, usually 180 degrees from the main attachment, that is used to reeve the rigging line in a set of blocks. |
| beer knot |
Knot commonly used to join two ends of a piece of tubular webbing to create a loop. See water knot |
| beer knot |
Knot commonly used to join two ends of a piece of tubular webbing to create a loop. See water knot. |
| belay |
Means of securing or slowing a climbing line by using wraps around a cleat, carabiner, or other device. |
| bend |
Type of knot used to join two rope ends together. Contrast with hitch. |
| bend radius |
Radius of an object around which a line passes. |
| bend ratio |
Ratio of the diameter of a branch, sheave, or other object to the diameter of the rope that is wrapped around it. |
| beneficial organisms |
Insects and other organisms that assist in plant health, such as the control of pest populations. |
| bight |
Curve or arc in a rope between the working end and the standing part. |
| Blake's hitch |
Friction knot climbers use, sometimes in place of the tautline hitch or Prusik knot. Learn how to tie a Blake's hitch. |
| block |
(1) Heavy-duty pulley used in rigging. Designed for dynamic loading. (2) Casing enclosing one or more parallel pullers. |
| block and tackle |
System of two or more pulleys with a rope or cable threaded between them, usually used to lift or pull heavy loads. |
| bowline |
Loop knot used to form single or double endline loop(s) in a rope, often to attach items to the rope. |
| bowline on a bight |
Knot used to form two loops in the standing part of a rope. |
| branch |
Stem arising from a larger stem. A subdominant stem. Pith in true branches has no connection to parent stem. |
| branch union |
Point where a branch originates from the trunk or another branch. Fork. Crotch. |
| breaking strength |
Force at which a new piece of equipment of rope fails under a static load. |
| buck strap |
Strap used in tree climbing, often employed for ascending trees with climbing spurs. Similar to a work-positioning lanyard. |
| bucking |
Cutting of a tree trunk or log into shorter, manageable sections. |
| bud |
Small lateral or terminal protuberance on the stem of a plant that may develop into a flower or shoot. Undeveloped flower or shoot containing a meristematic growing point. |
| bull rope |
Large-diameter rope used in rigging. |
| buntline hitch |
Simple hitch commonly used to attach a line to piece of hardware.
Learn how to tie a buntline hitch. |
| bushing |
(1)Metallic tube or lining, without moving parts, to reduce friction between mechanical parts such as a pulley or sheave and an axle; also the nonrotating sheave used to increase the end radius for the sling attachment. Contrast with bearing. (2)A device, often made of rubber or plastic, to reduce vibration or wear between mechanical parts. (3)A fitting used to connect plumbing parts of different diameters (such as in spray equipment) |
| butteryfly knot |
Knot that can be used to form a loop in the standing part of a line. |
| butt-hitching |
Method of lowering pieces when the rigging point is below the work, traditionally without the use of a block. Contrast with blocking. |
| buttress roots |
Roots at the trunk base that help support the tree and equalize mechanical stress. |
| butt-tying |
Tying off a limb at the butt (larger) end for rigging. |
| cabling |
Installation of steel or synthetic cable n a tree to provide supplemental support to weak branches or crotches. |
| caliper |
Thickness or diameter of the trunk of a tree taken at a certain height. |
| cambium |
Thin layer(s) of meristematic cells that give rise (outward) to the phloem and (inward) to the xylem, increasing stem and root diameter. |
| canker |
Localized diseased area on stems, roots, and branches. Often shrunken and discolored. |
| canopy |
Collective branches and foliage of a tree or group of trees' crowns. Aggregate or collective tree crowns. A canopy can be closed or partially closed as in a forest or woodland stand, or composed of both individual trees and closed canopy groups as in an urban forest canopy. |
| cant hook |
Lever with an adjustable hook and having a blunt end instead of a spike. Used for handling and rolling logs. Traditionally made with a stout wooden lever but now often made of metal. Contrast with peavey |
| carabiner |
Connecting device. Oblong metal ring used in climbing and static rigging that is opened and closed by a spring-loaded gate. Contrast with snap |
| central leader |
Main stem of a tree, particularly of an excurrent specimen. |
| chain-saw lanyard |
Short rope or webbing lanyard used for securing a chain saw to a climber's saddle. |
| chain-saw pants |
Trousers manufactured with a protective layer designed to slow or stop a chain saw chain. See chaps |
| chaps |
Form of leg protection or personal protective equipment (PPE) worn when operating a chain saw, to protect from chain saw injury. |
| chlorosis |
Whitish or yellowish leaf discoloration caused by lack of chlorophyll. Often caused by nutrient deficiency. |
| climbing hitch |
Hitch used to secure a tree climber to the climbing line, which permits controlled ascent, descent, and work positioning. |
| climbing line |
Rope that meets specifications for use in tree climbing. |
| climbing saddle |
Work-positioning harness designed for climbing trees. |
| climbing spurs |
Sharp devices strapped to a climber’s lower legs to assist in climbing poles or trees being removed. Also called spikes, gaffs, irons, hooks, or climbers. |
| clove + half hitch |
Combination of knots used to secure a rope to a tree section in rigging. |
| clove hitch |
Knot used to secure a rope to an object. |
| codominant branches/codominant stems |
Forked branches nearly the same size in diameter, arising from a common junction and lacking a normal branch union. |
| command and response system |
System of vocal communication used in tree care operations. |
| common cable |
In North America, flexible steel rope made up of seven wire strands that are twisted helically together. |
| compression wood |
Reaction wood in conifers that develops on the underside of branches or leaning trunks and is important in load bearing. |
| conk |
Fruiting body or nonfruiting body (sterile conk) of a fungus. Often associated with decay. |
| connecting device |
Mechanical connecting link. |
| contact insecticides |
Materials that cause insect injury or death on contact. |
| control line |
In speedlining, the line used to control the descent of the load on the speedline and to retrieve the pulley or traveler assembly. |
| conventional notch |
45-degree notch with a horizontal bottom cut. Used in removing trees or branches. Also called common notch. Contrast with Humboldt notch and open-face notch. |
| Council of Tree and Landscape Apprasers (CTLA) |
Group of representatives of several tree care and landscape associations that works to research and author the Guide for Plant Appraisal. |
| cow hitch |
Knot commonly used to attach hardware to a tree. Should be backed up or finished with a half hitch. Learn how to tie a cow hitch. |
| crotch |
(1) (noun) branch union or fork. (2) (verb) to place a line through a branch union. |
| crown |
Upper part of a tree, measured from the lowest branch, including all the branches and foliage. |
| crown cleaning |
In pruning, the selective removal of dead, dying, diseased, and broken branches from the tree crown. |
| crown raising |
In pruning, 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 restoration |
Method of restoring the natural growth habit of a tree that has been topped or damaged in any other way. Restoration pruning. |
| crown thinning |
In pruning, the selective removal of live branches to reduce crown density. |
| cut-surface application |
Method of placing herbicide on stumps immediately after cutting so that the herbicide is absorbed and translocated to the roots. Often used in utility arboriculture. |
| cycles to failure |
Number of times a rope or other piece of equipment can be used with a given load before mechanical failure. |
| dbh |
Acronym for tree diameter at breast height. Measured at 1.4 meters (4.5 feet) above ground in the United States, Australia (arboriculture), New Zealand, and when using the Guide for Plant Appraisal, 9th edition; at 1.3 meters (4.3 feet) above ground in Australia (forestry), Canada, the European Union, and in UK forestry; and at 1.5 meters (5 feet) above ground in UK arboriculture. |
| DdRT |
Acronym for doubled rope technique. Dynamic or static climbing system in which a rope is doubled over a branch and the climber utilizes both parts of the line. Contrast with DRT and SRT |
| dead-end grips (tree grips) |
Cable-termination devices that must be used to terminate extra-high-strength cable (EHS) tree support system cable to anchor hardware. May also be used with common-grade cable |
| dead-end hardware |
Lag-threaded cable anchor or bracing rod that is screwed directly into an undersized, pre-drilled hole in a tree but does not pass through to the other side. Contrast with through-hardware. |
| dead-eye sling |
Rope sling with a single eye spliced in one end. Also called eye sling, fixed-eye sling, or spliced-eye sling. |
| deadwooding |
Removing dead and dying branches from a tree. Outdated term for crown cleaning. |
| decay |
(1) (noun) an area of wood that is undergoing decomposition. (2) (verb) decomposition of organic tissues by fungi or bacteria. |
| deciduous |
Tree or other plant that sheds all of its leaves according to a genetically scheduled cycle as impacted by climate factors (usually during the cold season in temperate zones). Contrast with evergreen. |
| decline |
Gradually diminishing health or condition of a tree. |
| deficiency |
Pertaining to plant nutrition, lack or insufficient quantity of a required element. |
| defoliation |
Loss of leaves from a tree or other plant by biological or mechanical means. |
| degree day |
The difference between the daily average temperature and a given temperature base. |
| descender |
Device used to control friction when descending a climbing line. Contrast with ascender. |
| diagnosis |
Process of identifying a disorder by analyzing signs, symptoms, site conditions, patterns, climate, cultural history, and other factors to determine the causative agent(s). |
| dicotyledon |
Plant with two cotyledons in its embryo; netted or palmate leaf veins; and flowers with three, four, or five petals, or petals in multiples of these numbers. Contrast with monocotyledon. |
| dieback |
Condition in which the branches in the tree crown die from the tips toward the center. |
| dielectric |
Insulating (nonconducting) material. |
| diffuse porous |
Pattern of wood development in which the vessels and vessel sizes are distributed evenly throughout the growth ring. Contrast with ring porous. |
| direct cable system |
Simple tree cabling system joining two branches or leaders with a single cable. Contrast with box cable system and triangular cable system. |
| 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 little or no effect. |
| disease |
Condition that impairs the performance of one or more vital functions. Usually associated with infectious agents. |
| Distel |
Type of friction hitch used in climbing and rigging. Learn how to tie a Distel hitch. |
| dormancy |
Period of naturally reduced physiological activity in the organs of a plant with the potential for reactivation of growth. |
| dormant bud |
Bud originally developed in a leaf axil and connected to the pith by a bud trace that has not been stimulated to mature and grow. Some buds remain dormant throughout the life of a woody plant. |
| double braid |
Rope construction consisting of a braided rope within a braided rope, both of which carry part of the load. |
| double crotch |
Technique consisting of tying one climbing line or two climbing lines into two places in a tree. |
| double figure-eight knot |
Figure-eight knot tied with a double strand of rope. |
| double fisherman's bend |
In arboriculture, the name used for a knot that is commonly used to join two ropes or two ends of the same rope, as when forming a Prusik loop. Grapevine knot. |
| double half hitch |
Two half hitches tied in a series. |
| double hitch |
Technique consisting of securing a tree section with two load lines in rigging. |
| double-locking |
Pertaining to a carabiner, requring two distinct motions to prepare the gate to open. |
| downy mildew |
White, fungal-like growth that develops during wet periods, usually on the underside of a leaf. |
| drill-hole fetilization |
Applying fertilizer by drilling holes in the soil within the root zone. Contrast with broadcast fertilization and liquid fertilization |
| D-rings |
D-shaped metal rings on a climber's saddle for attaching ropes and snaps. |
| drip line |
Imaginary line defined by the branch spread of a single plant or group of plants. |
| drop cut |
branch-removal technique consisting of an undercut and then a top cut, usually made farther out on the branch, or with a chain saw, directly over the undercut. |
| drop line |
Rope used to secure the weight of a limb in rigging; load line. |
| drop start |
Technique used to start a chain saw by pushing the saw away from the body and simultaneously pulling the start cord. |
| drop zone |
Predetermined area where cut branches or wood sections will be dropped or lowered from a tree. See landing zone |
| drop-crotch pruning |
(obsolete) Term for a method of reducing the height of a tree. The general rule for cuts is that leaders should be cut back to a lateral capable of assuming apical dominance, if possible, usually at least one-third the diameter of the leader. See reduction. |
| DRT |
Acronym for double rope technique. Climbing system n which two separate ropes and two separate anchor points are utilized. Contrast with DdRT and SRT. |
| dynamic cable system |
Simple tree cabling system joining two branches or leaders with a single cable. Contrast with box cable system and triangular cable system. |
| dynamic load |
Forces created by a moving load. Load that changes with time and motion. Contrast with static load. |
| earth auger |
Drill bit with a wide, threaded shank used for drilling holes in the ground. See soil auger. |
| ectomycorrhizae |
type of mycorrhizae that grow between the cortical or epidermal cells of absorbing roots, forming an outer sheath around the root. See mycorrhizae Contrast with endomycorrhizae. |
| edema |
Watery swelling in plant tissue. |
| EHS Cable |
see extra-high-strength cable. |
| emergency response |
Predetermined set of procedures by which emergency situations are assessed and handled. |
| endomycorrhizae |
type of mycorrhizae that grow within root cells. See mycorrhizae. Contrast with ectomycorrhizae |
| epinasty |
Downward curling of the leaf blade resulting from more rapid cell growth on the upper side of the petiole than on the lower side. Often a symptom of plant disease. Distortion of growth, often caused by certain types of herbicides. |
| espalier |
(1) (noun) Specialized technique of pruning and training plants to grow within a plane, such as along a wall or a fence. (2) (noun) A plant trained in that manner. (3) (verb) To train plants in that manner. |
| essential elements |
17 minerals essential to the growth and development of trees. These minerals are essential because plants cannot complete their life cycle without them. See macronutrient, micronutrient, and primary elements. |
| ethephon |
Plant growth regulator used to promote fruit ripening. Also stimulates later flow in rubber trees. |
| evergreen |
Tree or other plant that does not shed all of its foliage annually. Contrast with deciduous. |
| exotic species |
Not native or indigenous to a region. May be invasive. Contrast with introduced species, native species, and naturalized species. |
| extra-high-strength (EHS) cable |
Type of 7-strand steel cable, other used to cable trees. Stronger but less flexible than common-grade cable. Must be terminated with dead-end tree grips. |
| eye bolt |
Cable anchor with a closed eye, usually machine threaded. Only drop-forged eye bolts are accepted and approved for tree support systems in the United States. |
| eye splice |
(1) in cabling, a closed termination loop, hand formed in common-grade cable by wrapping the successive strands back upon the standing part to attach the cable to anchor hardware. (2) a splice that forms a closed eye or loop. |
| eye-to-eye sling |
Eye-to-eye sling: sling (usually a length of spliced rope) with an eye at each end. Also called eye-and-eye sling. |
| face cut |
Notch cut used to help control the direction of fall of trees or branches being removed. |
| failure potential |
In tree risk assessment, the professional assessment of the likelihood for a tree or tree part to fail within a defined period of time. |
| fall protection |
Equipment and techniques designed to ensure a climber will not fall from a tree or an aerial lift. |
| false crotch |
Device installed in a tree to hold and direct ropes during climbing or rigging because there is not a suitable natural crotch available, or to protect an available crotch, and/or to reduce wear on ropes. |
| felling |
Dropping or cutting down a tree. |
| felling wedge |
A metal or plastic wedge inserted into the back cut to help direct to path in which a tree or tree part falls. |
| fertilization |
Application of essential elements to a plant, usually through the soil. |
| figure-8 descender |
Metal device used to provide friction on a rope in climbing or very light rigging. See descender. |
| figure-8 knot |
Particular knot tied as a safety knot of stopper knot at the end of a line. |
| fixed loop |
Webbing or rope sling consisting of a complete, closed loop. |
| fixed-eye sling |
Short sling with an eye spliced in one end. Also called dead-eye sling. |
| flip line |
Tree climbing lanyard, with or without a wire core, usually with a snap or carabiner at one end and an eye at the other end. Used for ascending trees when using spikes, for work positioning, and as a second means of life support when using a chain saw in a tree. |
| floating anchor |
Anchor point in a rigging system that can be moved anywhere between two points. |
| floating false crotch |
False crotch installed on an ascent line anchored high in a tree. |
| flush cut |
Pruning cut through and/or removing the branch collar, causing unnecessary injury to the trunk or parent stem. |
| foliage |
Leaves of a plant. |
| foliar application |
Applying a fertilizer, pesticide, or other substance directly to the foliage. |
| footlock (footlocking) |
Method of ascending a rope by wrapping the rope around the feet. See secured footlock |
| free climb |
Climbing a tree without being secured by a climbing rope. |
| French Prusik |
Type of friction hitch used in climbing and rigging. |
| friction |
specific type of force that resists the relative motion between two objects in contact. The direction is always opposite the motion. |
| friction device |
Device used to take wraps in a load line to provide friction for controlled lowering or climbing. |
| friction hitch |
Any of numerous knots used in tree climbing or rigging that may alternately slide along and then grip a rope. |
| friction saver |
Specific types of false crotch used for climbing trees; two rings connected by a strap. |
| frost crack |
Vertical split in the wood of a tree, generally near the base of the bole, caused by internal stresses and low temperatures. Radial shake. |
| fruiting body |
Reproductive structure of a fungus. The presence of certain species may indicate decay in a tree. See conk |
| fungicides |
Chemical compounds that are toxic to fungi. |
| fungus (pl. fungi) |
Group of organisms from the kingdom of Fungi, including yeasts, molds, mushrooms, and smuts. Typically multicellular, saprophytic, or parasitic and lacking vascular tissue and chlorophyll. Reproduces by spores borne in fruiting bodies. |
| gaff |
Pointed, spur portion of a climbing spike. |
| gall |
Abnormal swelling of plant tissues caused by gall wasps, mites, nematodes, and various insects and less commonly by fungi or bacteria. Contrast with burl |
| gate |
Mechanism to control the opening and closing of a connecting device. See carabiner and snap. |
| girdling |
Restriction or destruction of the vascular system within a root, stem, or branch that causes an inhibition of the flow of water and photosynthates in the phloem. |
| girdling root |
Root that encircles all or part of the trunk of a tree or other roots and constricts the vascular tissue and inhibits secondary growth and the movement of water and photosynthates. |
| girth hitch |
Simple knot used to attach a line, spliced eye, or endless loop to an object. |
| GRCS |
acronym for Good Rigging Control System, the brand name of a friction device used in rigging. |
| growth rate |
Speed at which something grows. |
| guy |
(1) a steel or synthetic-fiber cable between a tree or branch and an external anchor (another tree, the ground, or other fixed object) to provide supplemental support. (2) a steel cable between a utility pole and an external anchor (another pole, the ground, or other fixed object, which may sometimes be a tree) to keep the pole upright. Guys act in tension. Contrast with prop. |
| half hitch |
Simple knot used to temporarily attach a line to an object. Also used as a backup in combination with other knots. |
| hand pruning shears |
Tool used for pruning twigs of less than 1/2 inch (1.3 cm) diameter. |
| hanger |
Broken or cut branch that is hanging in a tree. |
| hard lay rope |
Rope manufactured with tightly wound strands, making it stiffer than standard lay or soft lay ropes. |
| Haven grip |
Device used to clasp and hold cables. |
| hazard |
Situation, condition, or thing that may be dangerous. (1) in tree management, a tree or tree part that is likely to fail and cause damage or injury, and the likelihood exceeds an acceptable level of risk. (2) in tree care or forestry operations, the presence of a condition or situation that may cause harm or injury to workers or others. |
| hazard assessment |
Systematic process of identifying hazards. See risk assessment. |
| hazard reduction pruning |
Type of pruning to remove dead, severely decayed, split, or other unsafe branches. |
| heading (heading back) |
Cutting a shoot back to a bud or cutting branches back to buds, stubs, or lateral branches not large enough to assume apical dominance. Cutting an older branch or stem back to a stub in order to meet a structural objective. |
| heart rot |
Any of several types of fungal decay of tree heartwood, often beginning with infected wounds in the living portions of wood tissue. |
| heartwood |
Wood that is altered (inward) from sapwood and provides chemical defense against decay-causing organisms and continues to provide structural strength to the trunk. Trees may or may not have heartwood. Contrast with sapwood. |
| heartwood rot |
Any of several types of fungal decay of tree heartwood, often beginning with infected wounds in the living portions of wood tissue. Also called heart rot. |
| herbicides |
Chemical compounds that kill vegetation. |
| hinge |
Strip of uncut wood fibers created between the face cut or notch and the back cut that helps control direction in tree felling or limb removal. Holding wood. |
| hinge cut |
Sequence of cuts used to control the direction of a limb being removed. |
| hitch |
(1) type of knot made when a rope is secured around an object or its own standing part. Contrast with bend. (2) a mechanical device for connecting a towing vehicle to a trailed or towed vehicle or implement. |
| holding wood |
Section of wood located between the face cut and the back cut that helps direct where the tree will fall. See hinge |
| hollow braid |
Rope construction consisting of a braided rope with no core. |
| honeydew |
Sugary substance secreted by certain insects, including aphids and some scale insects, when feeding on plants. |
| horizontal boring |
Boring, with special machinery, below the surface of the ground without an open trench. Alternative for installation of underground utilities that avoids cutting of tree roots or damage to hardscape or existing utilities. Contrast with radial trenching, trenching, and tunneling. |
| horticultural oils |
Highly refined petroleum oils that may be applied to plants to smother certain insects and other pests by disrupting their respiration. |
| host |
Living organism from which a parasite obtains nutrition. |
| Humboldt notch |
Felling notch that is horizontal on the top and angled on the bottom. Also called Humboldt scarf or reverse scarf. Contrast with conventional notch and open-face notch. |
| hydrogels |
Crystalline polymers tat absorb water and, if needed, can be added to the soil to increase its water-holding capacity. |
| included bark |
Bark that becomes embedded in a crotch (union) between branch and trunk or between codominant stems. Causes a weak structure. |
| increment borer |
Device used to take core samples from trees to determine age or detect problems, such as decay. |
| inoculants |
In soil science, microorganisms (e.g., mycorrhizae fungi) that are introduced into the soil in order to improve growth or plant health. |
| insecticidal soaps |
Soap-based pesticides approved for application to plants to kill insects and certain mites by disrupting the cell membranes. |
| insecticides |
Substances toxic to insects. |
| instar |
Stage of growth between molts in the development of insect larvae. |
| Integrated Pest Management (IPM) |
Method of controlling plant pests by combining biological, cultural, mechanical, physical, and/or chemical management strategies. |
| Intergrate Vegetation Management (IVM) |
System of managing plant communities in which compatible and incompatible vegetation are identified, action thresholds are considered, control methods are evaluated, and selected control(s) are implemented to achieve a specific objective. Choice of control methods is based on effectiveness, environmental impact, site characteristics, safety, security, and economics. |
| invasive species |
Non-native organisms likely to spread, disrupting the natural balance of an ecosystem. |
| kerf |
Slit or cut made by a saw in a log. Space created by a saw cut. |
| kerf cuts |
Cuts made to prevent fiber tearing from a branch or trunk section being removed. |
| kernmantle rope |
Rope construction with a cover and a core in which the core yarns are not braided. |
| key lock |
In carabiners, a specific configuration of the gate latch designed not to catch on ropes. Contrast with tooth lock. |
| kickback |
Sudden, sometimes violent and uncontrolled, backward, or upward movement of a chain saw. |
| kickback quadrant |
Upper quadrant of the tip of a chain-saw bar. |
| kilonewton (kN) |
Unit of force. Amount of force required to move 1,000 kilograms a single meter in a single second (equals 224.8 pounds of force). |
| knot |
Any of various fastenings formed by looping and tying a rope (or cord) upon itself or to another rope or to another object. |
| knotless system |
Rigging system in which loop slings and connecting links are used to attach branches or wood sections to the lowering line. |
| lag eye |
Lag-threaded cable anchor with a closed eye. |
| lag hook (J-hook) |
Lag threaded cable anchor with an open eye (J-shaped). |
| lanyard |
Short rope equipped with carabiners, snaps, and/or eye splices. Work-positioning lanyards are used for temporarily securing a climber in one place. |
| larva |
Immature life stage of an insect between the egg and the pupa stage. |
| latent bud |
Bud held in dormancy for more than one year by hormones originating from the terminal bud. Term sometimes used to refer to dormant buds or adventitious buds. |
| leach (leaching) |
(1) tendency for elements or compounds to wash down through the soil. (2) tendency for elements or compounds to wash into the soil. For example, alkaline compounds may leach from concrete, or heavy metals may leach from aggregates, and both may damage plants. |
| leader |
Primary terminal shoot or trunk of a tree. Large, usually upright stem. A stem that dominates a portion of the crown by suppressing lateral branches. |
| leaf margin |
Outer edge of the leaf blade. |
| leaf spot |
Patches of disease or other damage on plant foliage. |
| lenticel |
Small opening in the bark that permits the exchange of gases. |
| lifting cut |
Variation of the hinge-cut technique used to cut limbs that are being lifted. |
| lignin |
Organic substance that impregnates certain cell walls to thicken and strengthen the cell to reduce susceptibility to decay and pest damage. |
| limbing |
Cutting off the side branches of a felled tree. See crown raising. |
| line |
(1) rope that is configured, constructed, or intended for or assigned or restricted to a particular use (e.g., climbing line or lowering line). (2) a wire or cable designed to conduct electricity. (3) pertaining to electric utilities, the wires that serve as electrical conductors in an electric utility circuit. |
| lion tailing (lion's tailing) |
Poor pruning practice in which an excessive number of branches are thinned from the inside and lower part of specific limbs or a tree crown, leaving mostly terminal foliage. Results in poor branch taper, poor wind load distribution, and a higher risk of branch failure. |
| locking |
Pertaining to carabiners and snaps, requiring at least one distinct motion to prepare the gate to open (to unlock but not to actually open). |
| locking snap |
Snap that is self-closing and requires one motion to unlock and a separate motion to open the gate. Used by tree climbers primarily for connecting the climbing line to the saddle. |
| loopie |
Specific type of sling made up as an adjustable loop. |
| Machard |
Type of friction hitch used in climbing and rigging. |
| Machard tresse |
Type of friction hitch used in climbing and rigging. |
| machine-threaded |
Cable anchor or bracing rod with a fine-thread pattern that is used with a nut and washer and installed through a pre-drilled hole that is larger in diameter than the rod. Contrast with lag-threaded. |
| macroinfusion |
Trunk injection technique that requires a relatively large-diameter hole in the trunk. Contrast with implant, macroinjection, and microinjecton. |
| macroinjection |
Trunk injection technique that requires a relatively large-diameter hole in the trunk. Contrast with implant, macroinfusion, and microinjection |
| marline hitch |
(1) simple hitch used in lashing. (2) in rigging, a secondary knot used in combination with a primary attachment knot to tie off sections for lowering. |
| marline spike |
Tool that tapers to a point. Used for separating the strands of a rope in splicing and in marling. |
| microinjection |
Trunk injection technique using a small-diameter trunk penetration to introduce chemicals directly into the xylem. Contrast with implant, macroinfusion, and macroinjection. |
| micronutrient |
Essential element that is required by plants in relatively small quantities. Contrast with macronutrient |
| micropulley |
Small, light-duty pulley used in climbing operations. Often used as a knot tender. |
| minimum breaking strength |
Minimum load under which a new, unused rope or other piece of equipment will fail. Based on multiple trials and, for ropes, calculated as three standard deviations below the mean. |
| mites |
Small, often minute, arthropods n the order Acarina of the class Arachnida that may feed on plants, other mites or small insects. |
| miticides |
Chemical compounds that are toxic to mites. |
| monoculture |
The cultivation or planting of a single species on agricultural land, in a forest setting, or within an urban landscape. |
| moving block |
In a mechanical advantage pulley system, the pulley that moves. |
| Muenter hitch |
Hitch commonly used to belay a climber. |
| mulch |
Material that is spread or sometimes sprayed on the soil surface to reduce weed growth, to retain soil moisture and moderate temperature extremes, to reduce compaction from pedestrian or vehicle traffic or to prevent damage from lawn-maintenance equipment, to reduce erosion or soil splattering onto adjacent surfaces, to improve soil quality through its eventual decomposition, and/or to improve aesthetic appearance of the landscape. Mulch can be composed of chipped, ground, or shredded organic material such as bark, wood, or recycled paper; unmodified organic material such as seed hulls; organic fiber blankets or mats; or inorganic material such as plastic sheeting. See green mulch. |
| mycorrhizae |
Symbiotic association between certain fungi and the roots of a plant. |
| natural (target) pruning |
Process of branch removal n which the pruning cuts are made at nodes and in relation to the positions of the branch collar and branch bark ridge. |
| natural-crotch rigging |
Rigging methods that utilize natural crotches for the rigging points. |
| nematode |
Microscopic roundworm. Many are beneficial organisms, but some feed on plant tissues and may cause disease or damage. |
| nontarget organism |
an organism that is not intended to be damaged or killed by a pesticide, but that may still be susceptible to its effects. |
| notch gate |
In carabiners, a type of gate latch mechanism. Also called pin lock or or tooth lock. Has the disadvantage that it may catch on a rope. Contrast with key lock. |
| open-face notch |
Wedge-shaped cut (approx 70 degrees or greater) used in felling trees or removing, tree sections. Contrast with conventional notch and Humboldt notch |
| organic |
In chemistry, a substance containing carbon. In an applied arboricultural context, a substance, especially a fertilizer or pesticide, of animal or vegetable origin. Contrast with inorganic. |
| OSHA |
In the United States, the legislative act dealing with health and safety in the workplace; administered by the Occupational Safety and Health Administration; in Canada, Occupational Health and Safety Administration (OHSA) |
| outriggers |
Projecting structures used for stabilization on aerial devices, cranes, and other vehicles that support elevated or outstretched loads. |
| peavey |
Lever with an adjustable hook and a sharp spike instead of a blunt end. Used for handling and rolling logs. Traditionally made with a stout wooden lever but now often made of metal. Named for its inventor Joseph Peavey. Contrast with cant hook |
| Personal Protective Equipment (PPE) |
Personal safety gear such as hard hat, safety glasses, hearing protection, and leg protection, including chaps. |
| pest |
Organism (including, but not limited to, weeds, insects, or fungi) that is damaging, noxious, or a nuisance. |
| pesticide |
Any chemical used to control or kill unwanted pests such as weeds, insects, or fungi. |
| pesticide resistance |
Ability to withstand certain pesticides; survival of just a few genetically resistant pests that reproduce can lead to populations that are resistant. |
| pH |
Unit of measure that describes that alkalinity or acidity of a solution. Negative log of the hydrogen ion concentration. Measured on a scale. |
| phloem |
Plant vascular tissue that transports photosynthates and growth regulators. Situated on the inside of the bark, just outside the cambium. Is bidirectional (transports up and down). Contrast with xylem |
| photosynthesis |
Process in green plants (and in algae and some bacteria) by which light energy is used to form glucose (chemical energy) from water and carbon dioxide. |
| phytotoxic |
Term to describe a compound that is poisonous to plants. |
| plant grown regulator |
Compound effective in small quantities that affects the growth and/or development of plants. May be naturally produced (hormone) or synthetic. See plant hormone. |
| Plant Health Care (PHC) |
Comprehensive program to manage the health, structure, and appearance of plants in the landscape. |
| plunge cut |
Using the tip of a chain saw to cut into or through the middle of a piece of wood. Back-cut technique in which the hinge is established by cutting through the stem behind the notch then cutting back away from the hinge. Bore cut. |
| pole pruner |
Long-handled tool used to make scissor like, small pruning cuts that cannot be reached with hand tools. |
| pole saw |
Long-handled tool with a pruning saw on the end. |
| pollarding |
Specialty pruning technique in which a tree with a large-maturing form is kept relatively shorts. Starting on a young tree, inter-nodal cuts are made at a chosen height, resulting in the development of callus knobs at the cut height. Reguires regular (usually annual) removal of the sprouts arising from the cuts. |
| Port-a-Wrap III |
Brand name for the third generation of a device used to create and manage friction in the lowering line (load line) in rigging operations. |
| positive-locking |
(obsolete) In reference to carabiners and snaps, locking automatically and requiring two or more motions to prepare the gate to open. Prevents unintentional opening. |
| powdery mildew |
Any of various fungi of the genus Erysiphe producing powdery conidia that appears as a white, fuzzy coating on the upper leaf surfaces, often causing distortion of the leaf. |
| Preformed Tree Grip |
Brand of dead-end grip. |
| pruning |
Removing branches (or occasionally roots) from a tree or other plant using approved practices, to achieve a specified objective. |
| pruning saw |
Hand saw designed for pruning trees, generally with a bowed blade and teeth oriented for cutting on the pull stroke. |
| Prusik hitch |
Type of multi-wrapped friction hitch used in climbing and rigging. A common used it to attach the Prusik loop to the climbing line when footlocking. |
| Prusik loop |
Loop of rope used to form a Prusik hitch for climbing or rigging. |
| Prusik minding |
Specific type of pulley configured with extended cheekplates to keep a Prusik hitch from jamming in the sheave. |
| pull line (tagline) |
Line attached near the top of a tree to be felled or section of a tree to be removed to help pull or guide t in the desired direction or to control its swing. |
| pulley |
Device consisting of a rotating, grooved wheel between two side plates. Used to change the direction of pull in a line. May be used as part of a mechanical advantage system. Compare to block. |
| quick-release fertilizer |
Fertilizer with less than 50 percent water-nsoluble nitrogen (WIN). Contrast with slow-release fertilizer. |
| redirect |
(1)(verb) Changing the path of a climbing or rigging line to modify the forces on, or the direction of, the line. (2)(noun) A system installed to change the path of a climbing or rigging line. |
| reduction |
Pruning to decrease height and/ or spread of a branch or crown. See drop-crotch pruning. |
| rescue kit |
Climbing gear and emergency equipment that should be set out on every job site and available to conduct an aerial rescue and apply first aid. |
| rescue pulley |
Light-duty pulley used in light rigging operations. |
| resistance |
(1) In plants, the tendency to withstand, or to not develop, certain pest (including disease) problems; pest resistance. (2) In insects, the ability to withstand certain insecticides; survival of just a few genetically resistant insects that reproduce can lead to populations that are resistant. (3) In other pests, the ability to withstand certain pesticides. |
| Resistograph |
Brand name of a device consisting of a specialized micro-drill bit that drills into trees and graphs density differences that are used to detect decay. |
| retreat path |
Predetermined escape route away from a tree that is to be felled. Should be a 45-degree angle back and away from the direction of the falling tree and clear of obstruction. |
| rhizosphere |
Soil area immediately adjacent to, and affected y, plant roots. Typically has a high level of microbial activity. |
| rigging |
Method of using ropes and hardware (1) in tree pruning or removal, to control or direct the descent of cut material or to handle heavy loads. (2) with cranes, loaders, or other equipment, to life heavy loads. |
| rigging line |
Rope, usually the load line, used in rigging operations. |
| rigging point |
Placement in the tree (in a natural or false crotch) or any other point through which the load line passes to control rigging operations. |
| ring porous |
Pattern of wood development in which the large-diameter vessels are concentrated in the earlywood. Contrast with diffuse porous. |
| root pruning |
(1) in transplanting, the process of pre-digging a root ball to increase the density of root development within the final root ball. (2) in tree conservation and preservation, the process of pre-cutting roots behind the line of a planned excavation to prevent tearing and splintering of remaining roots. (3) in tree disease management, severing tree roots to prevent disease transmission through root grafts. |
| root:shoot ratio |
Relative proportion of root mass to crown mass. |
| rope |
A construction of braided or twisted strands to form a thick cord. See line. |
| rope bag |
Bag used to store climbing and rigging lines. |
| rope sling |
Length of rope, usually with at least one eye splice, used to secure equipment or tree sections in rigging operations. |
| running bowliner |
Bowline knot with the standing part of the line running through the loop. Often used to tie off and control branches or tree sections that are to be removed. Can be used when the desired tying point cannot be directly accessed by the worker. |
| running end |
End of a rope not in use. Contrast with standing part and working end. |
| rust |
Disease caused by a certain group of fungi and characterized by reddish brown spots on the foliage and/or the formation of stem galls. |
| safety eyeglasses |
Protective lenses that must be worn when conducting tree care operations. |
| safety lanyard |
A short rope equipped with snaps used for temporarily securing a climber in one place. |
| scabbard |
Protective sheath for a pruning saw or other tool. |
| scaffold |
(1)Pertaining to tree architecture or form, a strong and properly spaced arrangement, framework, or system of branches throughout the crown. (2)A work platform, which may be stationary or moving. |
| scale |
One of a group of insects that attach themselves to plant parts and suck the sap. |
| Scwabisch |
Type of friction hitch used in climbing and rigging. |
| secured footlock |
Method of footlocking in which the climber utilizes an additional means of securing against a fall. See footlock |
| selective herbicides |
Herbicides that are effective only on specific plant types (e.g., broadleaves, grasses) or species. |
| shackle |
U-shaped fitting with a pin running through it. Clevis |
| sheave |
Inner fitting within a block or pulley over which the rope runs. |
| sheepshank |
Knot used to form a loop in the middle of a line or to shorten a line. |
| sheet bend |
Knot used to attach two lines. The lnes can be of unequal diameter. Not to be used for life support. |
| ship auger |
Type of drill bit with an open spiral form. Used to drill holes in trees for cable or bracing installation. |
| shock-loading |
Dynamic, sudden force placed on a rope or rigging apparatus when a moving load or piece is stopped. |
| single action |
Pertaining to carabiners and snaps, requiring one motion for the gate to open. A nonlocking carabiner is single action. |
| single rope technique (SRT) |
A set of methods used to ascend (or descend) on a single leg of a single rope. |
| slack tender |
Any of several devices used to facilitate taking up slack in the climbing line. |
| sling |
Device used in rigging to secure equipment or pieces being rigged. |
| slippery bend |
Knot used to attach two lines that can be released quickly by pulling on the final tucked bight. |
| slow-release fertilizer |
Fertilizer that is at least 50 percent water-insoluble nitrogen (WIN). Rate of release may vary depending upon soil moisture and temperature. Contrast with quick-release fertilizer. |
| snap |
Connecting device used by tree climbers, primarily for connecting the climbing line to the saddle. Contrast with carabiner. |
| snap cut |
Cutting technique in which offset, bypassing cuts are made so that a section can be broken off easily. See mismatch cut. |
| snatch block |
Kind of block (pulley) that can be opened on one side to receive the bight of a rope. |
| snatching |
Rigging operation in which a section of upright stem is lowered off itself using a block or strop. |
| soil amendment |
Material added to soil to improve its physical, chemical, and/or biological properties. |
| soil analysis |
Analysis of soil to determine pH, mineral composition, structure, salinity, and other characteristics. |
| soil auger |
(1) Device for removing cores of soil for inspecting or testing. (2) Device (drill bit) used to drill holes in the soil for vertical mulching or for the drill-hole methods of fertilizing. See earth auger. |
| soil compaction |
Compression of the soil, often as a result of vehicle or heavy-equipment traffic, that breaks down soil aggregate and reduces soil volume and total pore space, especially macropore space. |
| soil horizon |
Layer or zone of the soil profile with physical, chemical, and biological characteristics that differ from adjacent layers. |
| soil-drench application |
Method of applying chemicals (usually herbicides or tree growth regulators) to trees through the soil. Normally done by excavating a shallow trench in the soil around the base of the trunk and pouring the compound into the trench. |
| sooty mold |
Fungus that appears as a black, sticky coating on the surface of leaves, fruits, branches, and other surfaces resulting from deposits of sugary excrement from aphids and scale insects. |
| spear cut |
Quickly cutting an upright branch so that it descends upright. |
| speedline |
Rigging line strung in such a way as to allow tree segments to slide to the ground at a distance away from the base of the tree and the drop zone for an ordinary lowering line. |
| topping |
Inappropriate pruning technique to reduce tree size. Cutting back a tree to a predetermined crown limit, often at internodes. |
| Tree |
A plant having a permanently woody main stem or trunk, ordinarily growing to a considerable height, and usually developing branches at some distance from the ground. |
