The vascular cambium is a thin layer of dividing cells. What does it produce?
Heartwood toward the inside and cork toward the outside
Phloem toward the inside and xylem toward the outside
Xylem toward the inside and phloem toward the outside
Bark toward the inside and pith toward the outside
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C. Xylem toward the inside and phloem toward the outside
The cambium lays down new xylem (wood) on its inner side and new phloem (inner bark) on its outer side, which is how the trunk grows in girth. The reversed order is a common mix-up.
Reference: Arborist certification study guide: Tree Biology (meristems)
Which of these is a sign rather than a symptom?
Dieback of branch tips
Wilting of the leaves
A fungal conk on the trunk
Yellowing between veins
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C. A fungal conk on the trunk
A sign is physical evidence of the causal agent itself, such as a fruiting body, insect, frass or ooze. Wilting, chlorosis and dieback are symptoms: the plant's response.
Reference: Arborist certification study guide: Diagnosis and Plant Disorders (signs and symptoms)
USDA plant hardiness zones are based on which climate measurement?
Average annual rainfall and snowfall
Average annual maximum summer temperature
Average length of the frost-free season
Average annual extreme minimum temperature
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D. Average annual extreme minimum temperature
The USDA hardiness zone map is drawn from the average coldest winter temperature each year, so it predicts cold survival only. It says nothing about summer heat, rainfall or soil.
Reference: USDA Plant Hardiness Zone Map; arborist study guide: Tree Selection
Tree risk is assessed by combining which two factors?
The likelihood of an event and its consequences
The species of the tree and the season of the year
The age of the tree and the cost of removing it
The height of the tree and the diameter of its trunk
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A. The likelihood of an event and its consequences
Risk combines how likely it is that a tree or part will fail and strike a target with how severe the consequences would be. Size and species influence those factors but are not risk in themselves.
Reference: ISA Tree Risk Assessment Best Management Practices
Which is the correct way to start a chain saw?
By drop-starting it, pushing the saw away while pulling the cord
On the ground or firmly supported, with the chain brake on
Resting on the operator's knee, with the bar pointing at the ground
Held in one hand at waist height, with the chain brake released
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B. On the ground or firmly supported, with the chain brake on
The saw is started with the brake on while held firmly on the ground or locked securely against the body in an approved position. Drop-starting leaves the saw uncontrolled and is prohibited.
Reference: ANSI Z133 (chain saws); arborist study guide: Safe Work Practices