Page 1 of 28
Louisiana Arborist Exam Study Guide
2025/2026 | 250+ Questions & Correct
Answers
1. A mature live oak (Quercus virginiana) in a residential yard
has developed a large cavity. As the arborist, you are asked
whether the tree is still safe. What is the most important factor
to evaluate?
A) The total age of the tree
B) The colour of the foliage
C) The thickness of the remaining sound wood in the cavity
wall
D) The presence of Spanish moss
Answer: C
Rationale: A tree’s structural integrity depends on the thickness
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of the sound wood remaining around a cavity. Live oaks
compartmentalise decay effectively, but if less than about 2
inches of sound wood remains, the tree’s strength is seriously
compromised, regardless of age or foliage colour.
2. What are the primary functions of a tree’s roots?
A) Photosynthesis, transpiration and reproduction
B) Anchorage, absorption, storage and conduction
C) Support, conduction and defence
D) Flowering, fruiting and seed dispersal
Answer: B
Rationale: Roots anchor the tree, absorb water and minerals,
store starches and other carbohydrates, and conduct these
resources upward. Leaves are responsible for photosynthesis and
transpiration.
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3. Which plant tissue is responsible for transporting water and
dissolved minerals from the roots to the leaves?
A) Phloem
B) Xylem
C) Cambium
D) Cortex
Answer: B
Rationale: Xylem consists of dead, hollow cells that form
continuous pipelines for water and mineral transport upward
(transpiration stream). Phloem transports sugars from leaves to
the rest of the tree.
4. A 15-year-old live oak has a pronounced, swollen area
where a large lateral branch joins the trunk. The swelling is
most likely:
A) A sign of stem canker
Louisiana Arborist Exam Study Guide
2025/2026 | 250+ Questions & Correct
Answers
1. A mature live oak (Quercus virginiana) in a residential yard
has developed a large cavity. As the arborist, you are asked
whether the tree is still safe. What is the most important factor
to evaluate?
A) The total age of the tree
B) The colour of the foliage
C) The thickness of the remaining sound wood in the cavity
wall
D) The presence of Spanish moss
Answer: C
Rationale: A tree’s structural integrity depends on the thickness
,Page 2 of 28
of the sound wood remaining around a cavity. Live oaks
compartmentalise decay effectively, but if less than about 2
inches of sound wood remains, the tree’s strength is seriously
compromised, regardless of age or foliage colour.
2. What are the primary functions of a tree’s roots?
A) Photosynthesis, transpiration and reproduction
B) Anchorage, absorption, storage and conduction
C) Support, conduction and defence
D) Flowering, fruiting and seed dispersal
Answer: B
Rationale: Roots anchor the tree, absorb water and minerals,
store starches and other carbohydrates, and conduct these
resources upward. Leaves are responsible for photosynthesis and
transpiration.
, Page 3 of 28
3. Which plant tissue is responsible for transporting water and
dissolved minerals from the roots to the leaves?
A) Phloem
B) Xylem
C) Cambium
D) Cortex
Answer: B
Rationale: Xylem consists of dead, hollow cells that form
continuous pipelines for water and mineral transport upward
(transpiration stream). Phloem transports sugars from leaves to
the rest of the tree.
4. A 15-year-old live oak has a pronounced, swollen area
where a large lateral branch joins the trunk. The swelling is
most likely:
A) A sign of stem canker
