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Categories All categories Arboriculture Terms
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- abioticnonliving.
- abiotic disorderplant ailment caused by nonliving. environmental. or man-made agents (contrast with biotic disorder).
- abrasionWearing. grinding. or rubbing away by friction
- abscisic acidplant hormone that stimulates stomatal closure and promotes seed and bud dormancy. Inhibits shoot growth but may promote root growth. Plays a role in wounding responses and in abscission ~ of leaves and fruit.
- abscissionleaf or fruit drop induced by hormonal changes.
- abscission zonearea at the base of the petiole where cellular breakdown leads to leaf and fruit drop.
- absorbing rootsfine roots that take up water and minerals. Most absorbing roots are within the top 12 inches (30 mm) of soil.
- absorptiontaking up (contrast with adsorption).
- accelerationrate of change of the velocity of an object. Acceleration is a vector quantity (see vector and velocity)
- acceptable riskthe degree or amount of risk that the owner. manager. or controlling authority is willing to accept.
- acceptable risk thresholdthe highest level of risk that does not exceed the owner/manager's tolerance.
- access line1) 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.
- access routedefined entrance and exit route for a property during construction. tree work. or landscape operations.
- accessory shootsee adventitious shoot.
- acclimationphysiological adaptation process of plants and other living organisms to a climate or en ironment different from their native environment or where originally grown.
- acidhaving a pH less than 7.0 (contrast with alkaline).
- aciditystate or quality of being acid (contrast with alkalinity; see pH).
- actinomycetesgroup of oil bacteria resembling fungi . Actinomycetes play a role in the decomposition of organic matter and the release of mineral elements.
- action threshold1) pest population or plant damage level that requires action to prevent irreversible or unacceptable physiological and/or aesthetic harm (see economic threshold). 2) a point at which the level of incompatible plant species. density. height. location. or condition threatens the stated(...)
- acuminateterm describing leaves that taper sharply at their tip (apex).
- acute1) disorder or disease that occurs suddenly or over a short period of time (contrast with chronic). 2) leaves with straight sides tapering to a pointed apex.
- adaptabilitygenetic ability of plants and other living organisms to adjust or acclimate to different environments.
- adaptive growthsee response growth.
- adhesionforce of attraction between two different materials; in soils. it is the attraction of water molecules to soil particles.
- adjustable balanceradjustable rigging sling used to balance tree limbs being removed in rigging operations.
- adpressedin close. tight proximity. Pressed close to or lying fiat against something. Appressed.
- adsorptionadhesion on contact of the molecules of gases. dissolved substances. or liquids to the surface of solids or liquids with which they are in contact (contrast with absorption).
- advanced assessmentan assessment performed to provide detailed information about specific tree parts. defects. targets. or site conditions. Specialized equipment. data collection and analysis. and/or expertise are usually required.
- adventitiousarising peripherally from parts of the root or stem and having no connection to meristems
- adventitious branchbranch arising from a stem or parent branch and having no connection to apical meristems.
- adventitious budbud arising from a place other than a leaf axil or shoot tip. usually as a result of hormonal triggers.
- adventitious rootroots arising from roots or stems and having no connection to apical meristems.
- adventitious root or budRoots or buds produced in situ from newly organized meristems; not preformed
- adventitious rootsroots arising from roots or stems and having no connection to apical meristems.
- aeration1) provision of air to the soil to alleviate soil compaction and improve its structure. 2) caused by exposure to air.
- aeration system1) set of holes or trenches created in a tree or other plant's root area to improve air circulation
- aerial (airborne) patrolinspection undertaken from a plane or helicopter; often used by electric utilities to monitor tree growth near electric transmission lines.
- aerial inspectioninspection of the upper tree parts not readily accessed from the ground; typically done by climbing or from an aerial lift.
- aerial rescuemethod of bringing an injured worker safely to the ground.
- aerial rootsaboveground roots. Usually adventitious in nature and sometimes having unique adaptive functions.
- aestheticpleasing to the senses. visually or otherwise. Artistic.
- agents of changeenvironmental. social. and public factors that influence the dynamics of the vegetation resource over time.
- aggregate1) close cluster or mix of small particles of aqueous solution to increase oxygen or other gas soil anchor organic matter of varying size that are bonded concentrations. Typically used to benefit organisms together. 2) sand. gravel. or small rocks in soil; anchor living or suspended in the(...)
- air excavation devicedevice that directs a jet of highly compressed air to excavate soil. Used to avoid or minimize damage to tree roots or underground structures such as pipes and wires. May also reduce hazards associated with excavation near pipes or wires.
- air excavatordevice that directs a jet of highly compressed air to excavate soil. Used within the root zone of trees to avoid or minimize damage to the roots. or near underground structures such as pipes and wires to avoid or minimize damage to them.
- air qualitypresence and concentration of pollutants in air.
- air terminaluppermost point of a tree lightning protection system.
- aircraft cablesteel wire rope of various constructions designated by the number of strands in the rope and the number of wires in each strand commonly used in cabling (in Australia and New Zealand) due to its high strength.
- alkalichemical compound that. in water solution. reacts as a base by forming hydroxyl ions (OH-). Commonly referred to as metal hydroxides." "
- alkali soilSoil in which sodium is the primary cation and is present in large enough quantities to adversely affect plant growth