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Categories All categories Arboriculture Terms
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- leaf axiledge of a leaf petiole where it meets the stem.
- leaf basebottom part of the leaf blade.
- leaf blotchirregularly shaped areas of disease on plant foliage.
- leaf marginouter edge of the leaf blade.
- leaf minerinsect that burrows between the leaf lamina.
- leaf scarscar left on the twig after a leaf is shed.
- leaf spotpatches of disease or other damage on plant foliage.
- leafletseparate part of a compound leaf blade.
- leafspotpatches of disease or other damage on plant foliage.
- leg protectiontype of personal protective equipment. Any clothing or device to protect the legs from various injuries. Chaps or other cut-resistant clothing worn over the legs when operating a chain saw.
- lenticelsmall opening in the bark that permits the exchange of gases.
- lesionlocal area of diseased or damaged tissue.
- lethalCapable of causing death
- life cycleseries of stages in the life of an organism (see life stage).
- life stageone of multiple phases in the growth and development of an organism.
- lifting1) in pruning. (crown) raising. 2) in rigging. technique in which the tip of a branch is raised up before lowering in order to avoid obstacles below.
- lifting cutvariation of the hinge-cut technique used to cut limbs that are being lifted.
- lignificationprocess in which cell walls become thicker and stronger by impregnation with lignin.
- limblarge. primary branch of a tree.
- limbingcutting off the side branches of a felled tree.
- limeCalcium carbonate (CaC03)
- limited visual inspectiona visual assessment from a specified perspective such as foot. vehicle. or aerial (airborne) patrol of an individual tree or a population of trees near specified targets to identify specified conditions or obvious defects.
- limiting factoran environmental factor that when absent or in low quantities limits the growth. abundance. or distribution of a plant.
- lineI) 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) in a utility system. the wires that serve as electrical conductors in an electric utility(...)
- line clearancesee utility line-clearance pruning.
- linera young tree planted out in nursery rows and grown to suitable landscape size (also known as lining-out stock). Many sizes and methods of propagation are used.
- lion tailingpoor 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.
- liquid fertilizationapplying liquid formulations of fertilizer by injection into the root zone of a tree or by application to soil surface or to foliage. Contrast with broadcast fertilization and drill-hole fertilization.
- liquid injectionsee liquid fertilization.
- live crown ratioratio of the height of the crown containing live foliage to the overall height of the tree.
- live crown ratio (LCR)ratio of the height of the crown containing live foliage to the overall height of the tree.
- load1) a general term used to indicate the magnitude of a force. bending moment. torque. or pressure applied to a substance or material. 2) cargo; weight to be borne or conveyed.
- strapping device used to secure loads.
- load linerope used to lower a tree branch or segment that has been cut. Lowering line.
- load-transfer linerigging technique in which a second load line is used. and some or all of the weight of the branch or wood section is transferred from the initial load line to the second.
- loamsoil texture classification based on a certain ratio of sand. silt. and clay. Considered ideal for plant growth.
- lobeleaf segments that project outward. creating voids (sinuses) between the segments (contrast with sinus).
- lockingpertaining to carabiners and snaps. requiring at least one distinct motion to prepare the gate to open (to unlock but not to actually open).
- locking snapsnap that is self-closing and requires at least one motion to unlock and a separate motion to open the gate. Used by tree climbers primarily for connecting the work-positioning lanyard to the harness.
- LOLERLifting Operations and Lifting Equipment Regulations
- loopbight that crosses itself.
- loopiean adjustable loop sling (compare with whoopie sling).
- lopperspruning tool with two long handles used to cut woody stems. typically up to an inch (2.5 mm) in diameter.
- loppingsee topping.
- low-growing plant communitya population of plants that have a low mature height (e.g.. 3 ft. [1 m] or less). Examples include grasses. shrubs. forbs. and herbs.
- low-voltage lines1) overhead or underground electric supply lines up to 750 volts [the threshold cited in Zl33 (U.S.) that requires 10-foot (3.05 m) separation without specialized training. etc.]. typically 120 to 480 volts. used to deliver electricity to end users (see secondary. distribution line. and(...)
- lowering devicea piece of equipment that is attached to the tree base or other anchor in rigging. Used to take wraps with the load lines to provide friction for controlled lowering of sections of a tree.
- lowering linesee load line.
- LPAlocal planning authority
- LPSlightning protection system