ISA Tree Risk & Management 3

Question 1

Which structural defect is characterized by a union where bark is trapped between two stems, reducing wood-to-wood contact?

Accepted Answer

Included bark

Answer

Included bark occurs when bark is embedded in a branch union, creating a weak attachment that is prone to splitting.

Question 2

What is the primary purpose of a 'static load test' on a tree?

Accepted Answer

Apply controlled force to assess structural response and root plate movement

Answer

A static load test uses a measured pulling force to evaluate how a tree and its root system respond to mechanical stress.

Question 3

Lion-tailing (removing inner foliage and branches) increases tree risk because it:

Accepted Answer

Concentrates weight at branch tips, increasing end-weight leverage

Answer

Lion-tailing shifts foliage to branch ends, creating heavy end-loading that dramatically increases the lever arm stress on branch attachments.

Question 4

A 'branch collar' should be preserved during pruning primarily because it:

Accepted Answer

Contains the vascular cambium needed to form callus and compartmentalize decay

Answer

The branch collar contains specialized tissues that produce callus wood and chemical barriers to compartmentalize and limit decay after pruning.

Question 5

Which of the following fungi is most associated with white rot, breaking down both lignin and cellulose?

Accepted Answer

Ganoderma applanatum

Answer

Ganoderma applanatum (artist's conk) is a classic white rot fungus that degrades both lignin and cellulose, leaving pale, fibrous wood.

(ISA) ISA Certified Arborist Practice Test