SAF Field Survey & Data Collection 2

Question 1

When using a prism or angle gauge in variable-plot sampling, a tree is counted in the plot when the tree's DBH appears:

Accepted Answer

Larger than the prism gap

Answer

A tree is tallied when its DBH appears larger than the prism gap, indicating the tree falls within the variable radius plot.

Question 2

What is the primary purpose of using a clinometer in forest inventory?

Accepted Answer

Measuring tree height by recording vertical angles

Answer

A clinometer measures vertical angles to calculate tree height using trigonometric relationships with a known horizontal distance.

Question 3

In forest mensuration, 'merchantable height' refers to the height of a tree from the stump to:

Accepted Answer

The point where the stem reaches a specified minimum top diameter

Answer

Merchantable height extends from the stump to the point where the stem diameter falls below a specified minimum usable diameter.

Question 4

A forester establishes 20 fixed-area plots, each 1/10 acre, and tallies 400 trees total. What is the estimated trees per acre?

Accepted Answer

200 trees/acre

Answer

With 400 trees on 20 plots × 1/10 acre each (= 2 acres total), trees per acre = 400 ÷ 2 = 200 trees/acre.

Question 5

Which sampling method is most appropriate when rare or clustered species need targeted detection across a large landscape?

Accepted Answer

Adaptive cluster sampling

Answer

Adaptive cluster sampling adds additional plots around any initial plot where the rare feature is detected, improving detection efficiency.

(SAF) Society of American Foresters Certification Practice Test