ISA Certified Arborist Chapter 12 (Tree Assessment and
Risk Management) with Correct Solutions
List the three components of risk assessment. - Answer -potential for failure
environment that may contribute to failure
potential target
By definition, if there is no _______, a tree cannot pose a risk. - Answer -target
When performing a tree assessment, it is important to develop and stick to a _______ process. - Answer
-systematic
For structural strength, branches should be _______ in diameter than their parent limbs or trunk. -
Answer -smaller
_______ _______ fungi primarily decay the lignin within and between cell walls in the wood. - Answer -
white rot
Codominant stems often have _______ ______ within the branch union, making them structurally less
stable. - Answer -included bark
Trees that have grown in dense shade such as a forest tend to have long, straight stems with little
_______. - Answer -taper
Trees often produce _______ _______, providing more stability to compensate for lean. - Answer -
reaction wood
Brown rot fungi primarily decay the _______, leaving behind the stiff lignin and thereby reducing the
bending strength of the tree. - Answer -cellulose
Decay located in the lower trunk and/or base of the tree is referred to as _______ _______. - Answer -
basal rot (butt rot)
In recent years, a number of more advanced _______ _______ _______ have been developed to help
arborists determine the presence and extent of decay inside trees. - Answer -decay detection devices
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. - Answer -true
List five indicators of decay in a tree. - Answer -open wounds or cavities
fruiting bodies: mushrooms, conks
cracked or loosened bark
Risk Management) with Correct Solutions
List the three components of risk assessment. - Answer -potential for failure
environment that may contribute to failure
potential target
By definition, if there is no _______, a tree cannot pose a risk. - Answer -target
When performing a tree assessment, it is important to develop and stick to a _______ process. - Answer
-systematic
For structural strength, branches should be _______ in diameter than their parent limbs or trunk. -
Answer -smaller
_______ _______ fungi primarily decay the lignin within and between cell walls in the wood. - Answer -
white rot
Codominant stems often have _______ ______ within the branch union, making them structurally less
stable. - Answer -included bark
Trees that have grown in dense shade such as a forest tend to have long, straight stems with little
_______. - Answer -taper
Trees often produce _______ _______, providing more stability to compensate for lean. - Answer -
reaction wood
Brown rot fungi primarily decay the _______, leaving behind the stiff lignin and thereby reducing the
bending strength of the tree. - Answer -cellulose
Decay located in the lower trunk and/or base of the tree is referred to as _______ _______. - Answer -
basal rot (butt rot)
In recent years, a number of more advanced _______ _______ _______ have been developed to help
arborists determine the presence and extent of decay inside trees. - Answer -decay detection devices
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. - Answer -true
List five indicators of decay in a tree. - Answer -open wounds or cavities
fruiting bodies: mushrooms, conks
cracked or loosened bark
