NR 220 Week 2 Forestry Exam Questions
and Answers
What are the objectives of forest inventory?
What are the procedural steps in a forest inventory? - correct answer-• Defining the
Population
- Figuring out what is possible for
us to measure.
- Stratified Sampling
• Selecting Plot Locations
- Simple Random Sampling vs
Systematic Sampling
• Navigating to the Plots
What is DBH? How is it measured? - correct answer-Diameter at Breast Height
- Outside bark diameter at 4.5ft above forest floor on the uphill side of tree
• What is basal area, basal area per acre, BAF, and how are they related? - correct
answer-Basal area is the area of a given section of land that is occupied by the cross-
section of tree trunks and stems at the base.
- In variable plot sampling, trees are counted if they appear larger than an angle (BAF)
projected from a sample point #𝑜𝑓𝑡𝑟𝑒𝑒𝑠×𝐵𝐴𝐹=𝐵𝐴𝑝𝑒𝑟𝑎𝑐𝑟𝑒
• What concepts are behind Variable Plot (prism) sampling? How does it work? - correct
answer-- Functions by diffraction, which offsets the thing we are looking at
- The angle of the glass (diopter) determines how much diffraction there is, which
corresponds to the BAF
• What is a "borderline" tree? How do you determine whether it is "IN" or "OUT" of your
sample? - correct answer-- Tree is counted if its image overlaps the image seen above
& below the prism
- Tree not counted if image does not overlap
- ON border trees it is necessary to check their limiting distance
and Answers
What are the objectives of forest inventory?
What are the procedural steps in a forest inventory? - correct answer-• Defining the
Population
- Figuring out what is possible for
us to measure.
- Stratified Sampling
• Selecting Plot Locations
- Simple Random Sampling vs
Systematic Sampling
• Navigating to the Plots
What is DBH? How is it measured? - correct answer-Diameter at Breast Height
- Outside bark diameter at 4.5ft above forest floor on the uphill side of tree
• What is basal area, basal area per acre, BAF, and how are they related? - correct
answer-Basal area is the area of a given section of land that is occupied by the cross-
section of tree trunks and stems at the base.
- In variable plot sampling, trees are counted if they appear larger than an angle (BAF)
projected from a sample point #𝑜𝑓𝑡𝑟𝑒𝑒𝑠×𝐵𝐴𝐹=𝐵𝐴𝑝𝑒𝑟𝑎𝑐𝑟𝑒
• What concepts are behind Variable Plot (prism) sampling? How does it work? - correct
answer-- Functions by diffraction, which offsets the thing we are looking at
- The angle of the glass (diopter) determines how much diffraction there is, which
corresponds to the BAF
• What is a "borderline" tree? How do you determine whether it is "IN" or "OUT" of your
sample? - correct answer-- Tree is counted if its image overlaps the image seen above
& below the prism
- Tree not counted if image does not overlap
- ON border trees it is necessary to check their limiting distance
