ISA TRAQ Vocabulary Exam Questions with Correct Answers Latest Update 2025/2026
advanced assessment {Level 3) - Answers an 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
acceptable risk - Answers the degree or amount of risk that the owner, manager, or controlling
authority is willing to accept.
acceptable risk threshold - Answers the highest level of risk that does not exceed the
owner/manager's tolerance.
adventitious branch - Answers branch arising from a stem or parent branch and having no
connection to apical meristems.
adventitious root - Answers roots arising from roots or stems and having no connection to
apical meristems.
aerial inspection - Answers inspection of the upper tree parts not readily accessed from the
ground; typically done by climbing or from an aerial lift
aerial patrol - Answers overflights of a utility right-of-way, large areas, or individual trees in a
defined area to record the location of trees that are likely to fail and cause harm.
analysis - Answers detailed examination of the elements or structure of something
angiosperm - Answers plant with seeds borne in an ovary: Consists of two large groups:
monocotyledons (grasses, palms, and related plants) and dicotyledons (most woody trees,
shrubs, herbaceous plants, and related planes) (contrast with gymnosperm).
annual rings - Answers rings of xylem that are visible in a cross section of the stem, branches,
and roots of some trees. In temperate zones, the rings typically represent one year of growth.
barrier zone - Answers a chemical and anatomical barrier formed by the cambium present at the
time of wounding in response to wounding. Inhibits the spread of decay into xylem tissue
formed after the time of wounding. Wall 4 in the CODIT model (contrast with reaction zone).
basal swelling - Answers increased wood growth in the area near or where the trunk and roots
come together.
basic assessment (Level 2) - Answers detailed visual inspection of a tree and surrounding site
that may include the use of simple tools. It requires that a tree risk assessor inspect completely
around the tree trunk looking at the visible aboveground roots, trunk, branches, and site.
bending moment - Answers a turning, bending or twisting force exerted by a lever, defined as
the force (acting perpendicular to the lever) multiplied by the length of the lever (see moment).
,biomechanics (tree biomechanics) - Answers the study of the action of forces on living trees.
bow - Answers leans characterized by the top of the tree bending over more than the lower trunk,
creating a curve.
brace rod (rigid brace) - Answers metal rod used to support weak sections or crotches of a tree.
bracket - Answers the fruiting body of a decay fungus (see conk).
breach of duty (of care) - Answers failure to take reasonable care to avoid injury or damage to a
person or property in a situation where the law imposes a duty of care.
brown rot - Answers fungal wood rot characterized by the breakdown of cellulose (contrast with
soft rot and white rot).
buckling - Answers failure mode characteristic of collapsing under compressive stress.
bulge - Answers swellings on branches, trunks, or root flares; often caused by new tissue
formed as a response to movement and that rein forces the wood structure at the weak area.
buttress root - Answers roots at the trunk base that help support the tree and equalize
mechanical stress.
butt rot - Answers decay of the lower trunk, trunk flare, or buttress roots.
cabling (flexible bracing) - Answers installation of steel or synthetic cable in a tree to provide
supplemental support to weak branches or branch unions.
callus - Answers undifferentiated tissue formed by the cambium, usually as the result of
wounding (contrast with woundwood).
cambium - Answers thin layer(s) of meristematic cells that give rise (outward) to the phloem
and (inward) to the xylem, increasing stem and root diameter.
canker - Answers localized diseased area on stems, roots, and branches. Often shrunken and
discolored.
cavity - Answers open or closed hollow within a tree stem, branch, or root, usually associated
with decay.
cellulose - Answers complex carbohydrate found in the cellular walls of the majority of plants,
algae, and certain fungi.
client - Answers the person or organization for whom professional services are rendered.
Usually, the owner or manager responsible for the trees.
clinometer - Answers instrument used for measuring the height of a tree or other structure.
, CODIT - Answers acronym for Compartmentalization of Decay in Trees (see
compartmentalization).
codominant (trees in a stand) - Answers more than one tree sharing dominance in a stand of
trees.
codominant stem - Answers forked branches nearly the same size in diameter, arising from a
common junction and lacking a normal branch union.
column of decay - Answers wood decay inside a tree that extends longitudinally up and down a
seem or through a branch.
compartmentalization - Answers natural defense process in trees by which chemical and
physical boundaries are created that act to limit the spread of disease and decay organisms
(see CODIT).
compression - Answers in mechanics, the action of forces to squeeze, crush, or push together
any material or substance (contrast with tension).
compression crack - Answers fracture caused by compressive stress.
compression wood - Answers reaction wood in gymnosperms, and some angiosperms, that
develops on the underside of branches or leaning trunks and is important in load bearing
(contrast with tension wood}.
conclusions - Answers the summary and results of a risk assessment.
conk - Answers fruiting body or nonfruiting body (sterile conk) of a fungus. Often associated
with decay (see bracket).
consequences - Answers outcome of an event.
consequences of failure - Answers personal injury, property damage, or disruption of activities
due to the failure of a tree or tree part.
constant occupancy - Answers a target is present at nearly all times, 24 hours a day, 7 days a
week.
corrected lean - Answers tree lean characterized by a leaning lower trunk and a top chat is more
upright as a result of self-correction; sweep.
crack - Answers separation in wood fibers; narrow breaks or fissures in stems or branches. If
severe, may result in tree or branch failure.
decay - Answers process of degradation by microorganism
center of force - Answers the point toward or from which a force acts; the resultant point of
advanced assessment {Level 3) - Answers an 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
acceptable risk - Answers the degree or amount of risk that the owner, manager, or controlling
authority is willing to accept.
acceptable risk threshold - Answers the highest level of risk that does not exceed the
owner/manager's tolerance.
adventitious branch - Answers branch arising from a stem or parent branch and having no
connection to apical meristems.
adventitious root - Answers roots arising from roots or stems and having no connection to
apical meristems.
aerial inspection - Answers inspection of the upper tree parts not readily accessed from the
ground; typically done by climbing or from an aerial lift
aerial patrol - Answers overflights of a utility right-of-way, large areas, or individual trees in a
defined area to record the location of trees that are likely to fail and cause harm.
analysis - Answers detailed examination of the elements or structure of something
angiosperm - Answers plant with seeds borne in an ovary: Consists of two large groups:
monocotyledons (grasses, palms, and related plants) and dicotyledons (most woody trees,
shrubs, herbaceous plants, and related planes) (contrast with gymnosperm).
annual rings - Answers rings of xylem that are visible in a cross section of the stem, branches,
and roots of some trees. In temperate zones, the rings typically represent one year of growth.
barrier zone - Answers a chemical and anatomical barrier formed by the cambium present at the
time of wounding in response to wounding. Inhibits the spread of decay into xylem tissue
formed after the time of wounding. Wall 4 in the CODIT model (contrast with reaction zone).
basal swelling - Answers increased wood growth in the area near or where the trunk and roots
come together.
basic assessment (Level 2) - Answers detailed visual inspection of a tree and surrounding site
that may include the use of simple tools. It requires that a tree risk assessor inspect completely
around the tree trunk looking at the visible aboveground roots, trunk, branches, and site.
bending moment - Answers a turning, bending or twisting force exerted by a lever, defined as
the force (acting perpendicular to the lever) multiplied by the length of the lever (see moment).
,biomechanics (tree biomechanics) - Answers the study of the action of forces on living trees.
bow - Answers leans characterized by the top of the tree bending over more than the lower trunk,
creating a curve.
brace rod (rigid brace) - Answers metal rod used to support weak sections or crotches of a tree.
bracket - Answers the fruiting body of a decay fungus (see conk).
breach of duty (of care) - Answers failure to take reasonable care to avoid injury or damage to a
person or property in a situation where the law imposes a duty of care.
brown rot - Answers fungal wood rot characterized by the breakdown of cellulose (contrast with
soft rot and white rot).
buckling - Answers failure mode characteristic of collapsing under compressive stress.
bulge - Answers swellings on branches, trunks, or root flares; often caused by new tissue
formed as a response to movement and that rein forces the wood structure at the weak area.
buttress root - Answers roots at the trunk base that help support the tree and equalize
mechanical stress.
butt rot - Answers decay of the lower trunk, trunk flare, or buttress roots.
cabling (flexible bracing) - Answers installation of steel or synthetic cable in a tree to provide
supplemental support to weak branches or branch unions.
callus - Answers undifferentiated tissue formed by the cambium, usually as the result of
wounding (contrast with woundwood).
cambium - Answers thin layer(s) of meristematic cells that give rise (outward) to the phloem
and (inward) to the xylem, increasing stem and root diameter.
canker - Answers localized diseased area on stems, roots, and branches. Often shrunken and
discolored.
cavity - Answers open or closed hollow within a tree stem, branch, or root, usually associated
with decay.
cellulose - Answers complex carbohydrate found in the cellular walls of the majority of plants,
algae, and certain fungi.
client - Answers the person or organization for whom professional services are rendered.
Usually, the owner or manager responsible for the trees.
clinometer - Answers instrument used for measuring the height of a tree or other structure.
, CODIT - Answers acronym for Compartmentalization of Decay in Trees (see
compartmentalization).
codominant (trees in a stand) - Answers more than one tree sharing dominance in a stand of
trees.
codominant stem - Answers forked branches nearly the same size in diameter, arising from a
common junction and lacking a normal branch union.
column of decay - Answers wood decay inside a tree that extends longitudinally up and down a
seem or through a branch.
compartmentalization - Answers natural defense process in trees by which chemical and
physical boundaries are created that act to limit the spread of disease and decay organisms
(see CODIT).
compression - Answers in mechanics, the action of forces to squeeze, crush, or push together
any material or substance (contrast with tension).
compression crack - Answers fracture caused by compressive stress.
compression wood - Answers reaction wood in gymnosperms, and some angiosperms, that
develops on the underside of branches or leaning trunks and is important in load bearing
(contrast with tension wood}.
conclusions - Answers the summary and results of a risk assessment.
conk - Answers fruiting body or nonfruiting body (sterile conk) of a fungus. Often associated
with decay (see bracket).
consequences - Answers outcome of an event.
consequences of failure - Answers personal injury, property damage, or disruption of activities
due to the failure of a tree or tree part.
constant occupancy - Answers a target is present at nearly all times, 24 hours a day, 7 days a
week.
corrected lean - Answers tree lean characterized by a leaning lower trunk and a top chat is more
upright as a result of self-correction; sweep.
crack - Answers separation in wood fibers; narrow breaks or fissures in stems or branches. If
severe, may result in tree or branch failure.
decay - Answers process of degradation by microorganism
center of force - Answers the point toward or from which a force acts; the resultant point of
