Isa Arborist Chapter 12: Tree Assessment And Risk Management

Front 1

List the three components of risk assessment.

Back 1

a. potential for failure
b. environment that may contribute to failure
c. potential target

Front 2

By definition, if there is no ____________, a tree cannot pose a risk.

Back 2

target

Front 3

When performing a tree assessment, it is important to develop and stick to a ____________ process.

Back 3

systematic

Front 4

For structural strength, branches should be ___________ in diameter than their parent limbs or trunk.

Back 4

smaller

Front 5

____________ ____________ fungi primarily decay the lignin within and between cell walls in the wood.

Back 5

white rot

Front 6

Codominant stems often have _____________ _________ within the branch union, making them structurally less stable.

Back 6

included bark

Front 7

Trees that have grown in dense shade such as a forest tend to have long, straight stems with little _______________.

Back 7

taper

Front 8

Trees often produce ____________ __________, providing more stability to compensate for lean.

Back 8

reaction wood

Front 9

Brown rot fungi primarily decay the ______________, leaving behind the stiff lignin an thereby reducing the bending strength of the tree.

Back 9

cellulose

Front 10

Decay located in the lower trunk and/or base of the tree is referred to as ____________ _______.

Back 10

basal rot (butt rot)

Front 11

In recent years, a number of more advanced __________ __________ ___________ have been developed to help arborists determine the presence and extent of decay inside trees.

Back 11

decay detection devices

Front 12

True/False---A tree may appear to be solid and structurally sound, and may have a thick, green canopy, yet can have significant decay inside.

Back 12

true

Front 13

List five indicators of decay in a tree.

Back 13

a. open wounds or cavities
b. fruiting bodies; mushrooms, conks
c. cracked or loosened bark
d. certain insects
e. birds, bees, other animals

Front 14

If decay is suspected at the root flare or in the major support roots, a root collar _____________ may be necessary to ascertain the extent.

Back 14

excavation

Front 15

Sometimes there are management options short of tree removal to abate the risk of failure. ________________ is the general term given to the process of reducing the risk potential.

Back 15

mitigation

Front 16

True/False---Current research indicates that filling cavities may do more harm than good because decay can develop in the interface between filler and tree.

Back 16

true

Front 17

List four potential options for mitigating tree risk.

Back 17

a. removal of the tree or limb(s)
b. pruning
c. cabling
d. bracing

Front 18

____________ occurs when the arborist has an obligation or responsibility with regard to the tree (duty) but fails to act reasonably in providing the service (breach of duty), and injury or damage occurs (harm) because of the arborist's action(s) or lack of action (causality).

Back 18

negligence

Front 19

The gauge against which acts are judged as reasonable is the ____________ _____ _________.

Back 19

standard of care

Front 20

True/False---Individuals may not escape liability for damages resulting from a fallen tree or branch if the defect that cause the failure was known of or should have been known of.

Back 20

true

Front 21

A necessary component in the existence of tree risk is
a. a tree with a potential for failure
b. an environment that may contribute to failure
c. a person or object that may be injured or damaged
d. all of the above

Back 21

d

Front 22

Which type of decay primarily affects the lignin within and between cell walls in the wood, reducing the tree's compressive strength?
a. brown rot
b. white rot
c. soft rot
d. sapwood rot

Back 22

b

Front 23

Following construction, forest trees on the edge of remaining stands are prone to failure due to
a. losing the protection of the trees that used to surround them
b. less trunk stability and poor taper
c. increased exposure to the weather elements
d. all of the above

Back 23

d

Front 24

Trees that lean because of ground failure or root injury
a. have a high potential to fail
b. are less of a risk than those that lean due to phototropism
c. are not a threat unless located at the edge of a wooded area
d. are a risk only if they begin to grow in compensation for the lean

Back 24

a

Front 25

Arborists, as trained professionals in tree care,
a. are required to have formal training in risk assessment
b. must be qualified to perform a root crown inspection
c. will be held to a higher standard of care than general citizens
d. all of the above

Back 25

c