Tree Risk & Management Flashcards
7 cards from real ISA practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Tree Risk & Management flashcards as text
Which of the following is an example of a 'mitigation' strategy that reduces the likelihood of impact rather than the likelihood of failure?
Answer: Closing a footpath under a high-risk tree during storms
Closing a path removes the target from the impact zone, reducing the likelihood of impact without changing anything about the tree itself.
Sudden Branch Drop syndrome is most likely to occur:
Answer: On calm, hot afternoons in summer, often on seemingly healthy branches
Sudden Branch Drop most commonly occurs on calm, hot summer afternoons and is not well understood but may relate to rapid moisture changes in the wood.
The 'zone of rapid taper' in a tree trunk is important because it indicates:
Answer: A location of high mechanical stress concentration and potential failure
Rapid taper at a given point in the trunk often corresponds to a structural adaptation to high stress concentrations, and anomalies here can signal increased failure risk.
When performing a basic tree risk assessment, which tool is used to detect hollow or decayed areas by sound?
Answer: Mallet or rubber mallet (sounding)
Sounding with a mallet is a simple, non-destructive technique where hollow or decayed wood produces a dull thud compared to the solid sound of intact wood.
Which condition would most likely cause a previously stable tree to become a high risk after a construction project nearby?
Answer: Grade change that raises soil level over the root zone
Raising the soil grade over tree roots reduces oxygen to the root zone, causes root decay, and can directly kill feeder and structural roots.
An arborist recommends a 'crown reduction' to reduce risk. According to ISA BMPs, the cuts should be made:
Answer: To lateral branches at least one-third the diameter of the stem being removed
ISA BMPs require crown reduction cuts be made to laterals large enough (at least 1/3 the diameter of the removed portion) to serve as the new terminal and sustain growth.
Which of the following soil conditions would MOST increase the risk of whole-tree windthrow for a large tree?
Answer: Shallow soil over a restrictive hardpan layer with a seasonally high water table
Shallow soil over hardpan prevents deep root development, and a high water table saturates soil and reduces frictional resistance, dramatically increasing windthrow risk.