Levels of Assessment

Question 1

categorization of the breadth and depth of analysis used in an assessment

Answer 1

Level(s) of assessment

Question 2

a visual assessment from a specified perspective such as a foot, vehicle, or aerial (airborne) patrol of an individual tree or a population of trees near specified targets to identify conditions or obvious defects of concern.

Answer 2

Limited visual assessment (level 1)

Question 3

a defined set, group, or collection of trees.

Answer 3

Tree population

Question 4

a limited visual inspection, usually from one side of the tree, performed as the tree risk assessor walks by the tree(s)

Answer 4

Walk-by (assessment)

Question 5

limited visual inspection from only one side of the tree, performed from a slow-moving vehicle. Also may be called a windshield assessment.

Answer 5

Drive-by (assessment)

Question 6

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.

Answer 6

Aerial patrol

Question 7

a remote sensing method that uses laser technology to measure tree size and location in relation to the target of concern.

Answer 7

LiDAR

Light Detection and Ranging

Question 8

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.

Answer 8

Basic assessment (level 2)

Question 9

a measuring tape scaled such that when it encircles a tree trunk, the width can be read directly.

Answer 9

Diameter tape

Question 10

instrument used for measuring the height of a tree or other structure.

Answer 10

Clinometer

Question 11

a broad headed hammer made of wood, plastic, or resin used for “sounding” a tree.

Answer 11

Mallet

Question 12

a stiff, small-diameter rod, stick, or wire that is inserted into a cavity or crack to estimate its size or depth.

Answer 12

Probe

Question 13

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.

Answer 13

Advanced assessment (level 3)

Question 14

inspection of the upper tree parts not readily accessed from the ground; typically done by climbing or from a lift.

Answer 14

Aerial inspection

Question 15

an instrument or tool developed to detect decay in tree parts.

Answer 15

Decay-detection device

Question 16

degradation of the ability to withstand mechanical stress.

Answer 16

Strength loss

Question 17

a device consisting of a specialized micro-drill bit that drills into trees and graphs resistance to penetration; used to detect internal differences in the wood, such as decay.

Answer 17

Resistance-recording drill

Question 18

a process of measuring wood density, or other mechanical properties, using an instrument that transmits, receives, and records the velocity of sound or electric waves through wood.

Answer 18

Sonic assessment

Question 19

use of multiple sensors placed around a trunk of limb to record sound or magnetic waves traveling through the wood, with measurements resulting in a picture of internal density characteristics. Typically used in arboriculture to measure the extent of decay in trees.

Answer 19

Tomography

Question 20

roots at the base that help support the tree and equalize mechanical stress.

Answer 20

Buttress roots

Question 21

process of removing soil to expose and assess the root collar (root crown) of a tree.

Answer 21

Root collar excavation (RCX)

Question 22

a nondestructive device that uses radar pulses to image the subsurface.

Answer 22

Ground-penetrating radar

Question 23

in advanced tree risk assessment, pulling tests to measure or observe the amount of inclination and/or deformation to assess stability.

Answer 23

Load testing

Question 24

a load test that involves installing a line in a tree, and the pulling and releasing the line several times to move the tree or branch. Most commonly used in a pre-work inspection, but can be used as part of an advanced tree risk assessment.

Answer 24

Hand pull test

Question 25

in advanced tree risk assessment, a load test that measures outermost fiber strain in the stem or branches, and/or inclination at the root flare, in response to a controlled pull.

Answer 25

Static pull test

Question 26

True/False
If an assessor determines that further inspection is required, s/he should go ahead and inspect the tree at a more detailed level of assessment.

Answer 26

False

Question 27

True/False

A drive-by assessment may be a reasonable method to quickly assess immediate risks in a large population of trees.

Answer 27

True

Question 28

True/False

Tools used for a Level 2 assessment might include diameter tape, a trowel, and a mallet.

Answer 28

True

Question 29

True/False
When assessing street trees, the targets may be consistent along the entire street and the likelihood of impact and consequences of failure may be held constant.

Answer 29

True

Question 30

True/False

If all techniques in a Level 3 assessment were sued, an assessor could predict with certainty when the tree would fail.

Answer 30

False

Question 31

A __________ is a limited visual inspection of one or more sides of the tree, performed as the inspector passes a tree on foot.

Answer 31

walk-by assessment

Question 32

A simple tool used for a basic assessment might include a __________, which can help determine the presence of decay when inserted into a cavity.

Answer 32

probe

Question 33

A __________ test can be performed with a light-duty line to look for signs of excessive movement in the branches, or instability in the trunk. A __________ test measures fiber strain in the stem and branches, and inclination in the root flare.

Answer 33

hand pull

static pull

Question 34

One example of a level __________ assessment is sonic tomography, where sound waves traveling through wood are used to create a tomogram.

Answer 34

three

Question 35

The amount and extent of internal decay can be estimated by

A) observing response growth and compartmentalization
B) sounding and/or probing
C) performing advanced assessment techniques
D) all of the above

Answer 35

D) all of the above

Question 36

The reason three levels of assessment are defined is

A) to provide one level each for municipal, utility, and commercial applications
B) because arborists must look above ground, below ground, and inside of a tree
C) not all trees or situations require the same depth and breadth of assessment
D) all of the above

Answer 36

C) not all trees or situations require the same depth and breadth of assessment

Question 37

Which of the following is NOT part of the Level 1 assessment process?

A) assess the tree(s) of concern from the defined perspective (e.g., walk-by, drive-by)
B) record locations of trees that meet the defined criteria (e.g., significant defects or other conditions of concern)
C) sound and/or probe trees with obvious cavities to determine the extent of decay
D) identify trees needing a higher level of assessment and/or prompt action

Answer 37

C) sound and/or probe trees with obvious cavities to determine the extent of decay

Question 38

A Level 2 assessment requires the assessor to

A) inspect completely around the tree
B) inspect the visible buttress roots
C) inspect the trunk and branches
D) all of the above

Answer 38

D) all of the above

Question 39

Which of the following tools are commonly used in a Level 2 assessment, but are not required?

A) air excavation device
B) mallet and probe
C) decay detection device
D) inclinometer

Answer 39

B) mallet and probe

Question 40

Level 3 assessments are generally more time intensive and more expensive than Level 2 assessments because

A) they require specialized equipment, data collection and analysis, and/or expertise
B) the potential consequences of tree failure are significantly higher than normal
C) they involve trees with the highest likelihood of failure
D) all of the above

Answer 40

A) they require specialized equipment, data collection and analysis, and/or expertise

Question 41

Level 3 assessments are typically performed

A) routinely, after most limited visual assessments, to follow up on trees of concern
B) in conjunction with or after a basic assessment, if an assessor needs additional information to assess the risk, and if the tree owner/manager approves the additional service
C) whenever internal decay is suspected, to provide additional information about the extent and location of the decay
D) whenever more information is required than can be determined from a basic assessment, regardless of the level of risk

Answer 41

B) in conjunction with or after a basic assessment, if an assessor needs additional information to assess the risk, and if the tree owner/manager approves the additional service