Chapter 12 Tree assessment and risk management Flashcards
List 3 components of risk Assessment
Potential for failure
Environment that may contribute to failure
Potential target
By definition, if there is no _______ a tree cannot pose a risk.
Target
When performing a tree assessment it is important to develop and stick to a _____ process.
Systemic
For structural strength, branches should be _________ in diameter than their parent limbs or trunk
Smaller
________ _______ fungi primarily decay the lignin within and between cell walls in the wood.
White rot
Codominant stems often have ________ ________ within the branch union, making them structurally less stable.
Included bark
Trees that have grown in dense shade such as a forest tend to have long, straight stems with little ______
Taper
Trees often produce ______ _____, providing more stability to compensate for lean.
Reaction wood
Brown rot fungi primarily decay the ________, leaving behind stiff lignin and thereby reducing the bending strength of the tree.
Cellulose
Decay located in the lower trunk and or base of the tree is referred to as ________ _____
Basal rot
In recent years, a number of more advanced __________ _________ __________ have been developed to help arborists determine the presence and extent of decay inside trees
Decay detection devices
A tree may appear to be solid and structurally sound, and may have a thick, green canopy, yet can have significant decay inside .
True
List 5 indicators of decay in a tree.
Open wound or cavities Fruiting bodies; mushrooms, conks Cracked or loosened bark Certain insects Birds, bees, other animals
If decay is suspected at the root flare or in the major support roots, a root collar _______ may be necessary to ascertain the extent.
Excavation
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.
Mitigation
Current research indicates that filling cavities may do more harm than good because decay can develop in the interface between filler and tree.
True
List 4 potential options for mitigating tree risk.
Removal of the tree or limbs
Pruning
Cabling
Bracing
__________ occurs when the arborist has an obligation or responsibility with regard to the tree but fails to act reasonably in providing the service and injury or damage occurs because of the arborists actions or lack of action.
Negligence
The gauge against which acts are judged as reasonable is the
Standard of care
Individuals may not escape liability for damages resulting from a fallen tree or branch if the defect that caused the failure was known of or should have been known of.
True
Soft rot
Decay of plant tissues characterized by the breakdown of tissues within the cell walls
