Glossary

split-tailshort length of rope used to tie the friction hitch in a climbing system.

splitsopen cracks or fissures in tree trunks or branches.

square knotknot used to tie together two ropes of equal diameter. Also called reef knot.

SRTsingle rope technique

SSISustainable Sites Initiative

stage diggingprocess to reduce sudden stress when deciduous plants must be dug in leaf. The root ball is dug (and roots are cut) section by section over a period of time.

stakeholderperson or group that has an interest in. -I or is affected by. an activity or decision.

stakingsupporting a tree with stakes and ties. Usually used in reference to newly planted trees.

stalksupport axis of an organ. Term often used as a substitute for petiole. peduncle. pedicel. stem. or filament.

standard down conductorlength of copper cable used in lightning protection system on trees.

standing partinactive part of a rope (contrast with running end and working end).

starchchain of sugar molecules linked together that serves as a form of energy storage in plants (see carbohydrate).

starting comerlower. front tip of a chain saw bar that is used to begin a bore cut.

static cable systemcabling system that utilizes rigid materials such as rods and steel cable to limit movement and provide constant support of limbs.

static loadconstant load exerted by a mass due to its weight (contrast with rfy11a111ic load).

static removable (retrievable) false crotchfalse crotch. usually an arborist block. that can be set in a tree and removed from the ground.

staticsstudy of forces in equilibrium (see Tree Statics).

stationary working linea fixed. non-moving rope. anchored in the canopy or at the base of the tree used for access and/or work positioning.

steel-core lanyardwork-positioning lanyard containing a steel core for stiffness and strength. Not considered chain-saw resistant. Should not be used near electrical conductors.

stelecentral cylinder containing vascular tissue located inside the cortex of stems. branches. and roots. Includes phloem. xylem. and endodermis.

stemwoody structure bearing foliage and buds that give rise to other stems (branches).

stem-girdling roota root that grows tangentially across a stem causing vascular constriction (see girrfli11g root).

step potentialvoltage between the feet of a person standing near an energized grounded object.

step voltagedifference in electrical potential between two points. which. when significant. can lead to electrocution if contacted simultaneously.

stipplingspeckled or dotted areas on foliage or bark.

stock1) the plant part in grafting to which the scion is joined. 2) nursery stock.

stocking (stocking density)ln forestry. a measure of the existing tree density compared to what is considered optimal. In urban forestry. the number of street trees present compared to the number of planting spaces available.

stomataMinute openings in the leaves through which gas exchange occurs. including water vapor and carbon dioxide

stomata (stomates)small pores. between two guard cells on the undersides of leaves and other green plant parts. through which gases are exchanged and water loss is regulated.

stopper knotknot. usually a figure-S knot. tied in the end of a line or in the tail of a knot to prevent the end or tail from passing through the knot.

stormwater runoffwater originating from precipitation (rain or melting snow and ice) that flows above ground rather than infiltrating into the soil. May occur if soils are frozen or saturated or if the rate at which precipitation falls is greater than the infiltration rate of a soil.

strand1) in rope. the largest component; composed of twisted yarn; strands are twisted (usually in the opposite direction of yarn) or braided to form rope. 2) in cable. a single wire component.

streaks or flakes on leaf tissuefoot-candle

stropshort length of rope used to attach part of a rigging or climbing system to a tree. The term is often used in place of lanyard (e.g.. chain-saw strop).

structural cellsmodular system consisting of units of soil and integrated support structures that serve as both a foundation for paved surfaces and a hospitable environment for tree root growth.

structural pruningpruning to establish a strong arrangement or system of scaffold branches.

structural rootslarge. woody. tree roots that anchor and support the trunk and crown. Roots characterized by secondary thickening and relatively large diameter. giving form to the root system and functioning in anchorage and support.

stubportion of a branch or stem remaining after a stub cut. branch breakage. or branch death.

stub cutsimproper pruning cuts made too far outside the branch bark ridge or branch collar that leave branch tissue attached to the stem.

stumpbase part of a tree that remains standing after the tree has been felled.

stump grinderspecialized power equipment used to remove tree stumps by grinding away the solid wood. May be towed or self-propelled. Stump machine. Stumper.

stuntinggrowth reduction of organisms. specifically plants or plant parts.

sub-oppositeleaf arrangement in which leaves are nearly opposite. but are slightly alternate. with one bud slightly below the one opposite.

subordinate1) v. prune to reduce the size and ensuing growth of a branch in relation to other branches or leaders. 2) adj. dominated by other trees. branches. or parts; suppressed.

subspeciesgroup of plants within a species having distinct differences that occur naturally. usually within a specific geographic region.

substationin an electric utility system. the beginning of the distribution network; a facility that steps-down voltages between transmission lines and primary lines or distribution feeders.

substratea layer of material below the soil surface; materials used to provide plant support. regulate moisture. and (in many cases) provide mineral nutrients to container plants.

subsurface applicationplacement of fertilizer or other material below the soil surface.

suckershoot arising from the roots (contrast with watersprout).