Urban Tree Risk Assessment & Mitigation Flashcards

Which root defect is most commonly associated with trees planted too deeply in urban settings?

Answer: Circling roots

Circling or girdling roots frequently develop when trees are planted too deeply or confined in pots, restricting vascular flow and structural stability.

When applying the ISA tree risk assessment matrix, a 'Likelihood of Failure' rated as 'Probable' combined with 'Consequences of Failure' rated as 'Significant' produces what overall risk rating?

Answer: High

The ISA matrix places Probable likelihood × Significant consequences in the High risk category.

Which tool is most appropriate for detecting internal decay in a standing urban tree without causing additional wounding?

Answer: Resistograph

The Resistograph uses a fine drill to measure resistance and detect voids or decay with minimal wounding compared to increment borers.

A mature cottonwood overhangs a busy pedestrian walkway in Albuquerque. The primary target category that drives risk rating in this scenario is:

Answer: Occupancy rate of the target

Target occupancy—how frequently people or property occupy the impact zone—is the key factor in determining consequence severity.

What mitigation action best reduces the likelihood of failure for a co-dominant stem union with included bark?

Answer: Structural cabling

Structural cabling limits the independent movement of co-dominant stems, reducing stress at the weak union with included bark.

Under the ISA BMP for risk assessment, a 'Basic Assessment' is most appropriate when:

Answer: A routine visual observation is needed from ground level

A Basic Assessment involves a visual, ground-level inspection without specialized equipment and is used for routine tree evaluations.

Sapwood staining in an Albuquerque ash tree is most likely an early indicator of:

Answer: Verticillium wilt

Verticillium wilt causes characteristic vascular staining visible in cross-sections of sapwood, common in ash and other hosts in the Southwest.