EXAM II FR 3218/5218 Semester II - 2003
If it is not clear what a question is asking, request clarification from the instructor. Misreading a question is not grounds for partial credit. To receive partial credit for the calculation problems, formulas and intermediate calculations must be legibly shown. The number preceding the question number is the point value of that particular question. Any number of multiple-choice options (including zero) may be correct responses to the question statement; circle all correct responses. Total points = 41.
(4) 1. In two-stage sampling of a large, heterogeneous population where the majority of the variability is within (versus between) the super units (primary sample units):
a. we should sample more super units, i.e. make n larger
b. the best two-stage design will approach cluster sampling (m=M)
c. the standard error for two-stage sampling will approach that of a simple random sample of size n*m
d. travel costs become completely irrelevant in the selection of a design
(4) 2. The four types of volume tables we identified in class differed in terms of the measurements they required and therefore their theoretical accuracy in predicting tree volume. Answer the questions below based on this measurements/accuracy tradeoff.
i) Why are composite volume tables (versus form class and standard volume tables) popular in Lake States forestry practice?
ii) Why are local volume tables generally preferred over standard or composite volume tables when cruising a moderate value, individual stand of timber?
(4) 3. It would likely be reasonable to use the constant form volume equation
V = b1 D2H
where D = DBH, when:
a. V is total cubic foot volume and H is total height
b. V is cordwood volume to a 4-inch top and H is merchantable height to a 4-inch top
c. V is cubic foot volume to a 4-inch top and H is merchantable height to a 4-inch top
d. V is cubic foot volume to a 4-inch top and H is total height
(6) 4. Using the following taper equation for red pine
where d = diameter (inches) at height h (feet) up the bole, D=DBH (inches), H= total height (feet):
i) Setup the integral for determining the cubic foot volume in the second 16-foot log (second log is above the first log in the tree bole) of a 12-inch DBH, 64-foot tall red pine tree. Ignore allowances for trim and kerf. Assume no stump. (You can get 2 points extra credit for correctly evaluating the integral)
ii) Using Doyle’s log rule for 16-foot logs (Bd. Ft. Doyle = (d-4)2, where d = small-end diameter of the log, rounded down to the whole inch) estimate the board foot content of the second 16-foot log (second log is above the first log in the tree bole) in a 12-inch DBH, 64-foot tall red pine tree. Ignore allowances for trim and kerf. Assume no stump.
(4) 5. You want to put 20, 1/15-acre plots in a 50 acre stand using a square grid arrangement.
i) What should the distance between plots (and distance between lines) be?
ii) How would you introduce randomness into your layout?
(2) 6. Why/when do we tally individual plots on separate tally sheets instead of putting all plot tallies on a single sheet?
(2) 7. For which tract shape below (same total acreage in each tract) would correct handling of boundary overlap (e.g. using the mirage method) be more important? Mark your answer with a big X.
(5) 8. Trees of the following DBHs (inches) were tallied on one, 1/30-acre fixed-radius plot:
8, 12, 10, 8
i) What is the observation of trees per acre for the plot?
ii) What is the observation of basal area per acre for the plot?
(3) 9. Provide the per acre stock table entry for 10-inch DBH birch if 30 such trees were tallied on 15, 1/10-acre plots and the sum of total heights for the 30 trees was 1500 feet. The volume equation available is:
V (cubic feet) = 0.0023 D2H
where D = DBH (inches), H = total height (feet).
(4) 10. Which of the following would always result in tallying too few trees with variable-radius plots:
a. keeping your eye over plot center when using a prism
b. not accounting for sloping terrain
c. keeping the angle gauge over plot center
d. tallying “every other one” borderline tree
(3) 11. A 12.6-inch DBH tree is found to be 26.4 feet (horizontal distance to tree center) from a sample location. Should the tree be tallied if you are using a 20BAF instrument? Calculations must be shown to receive any credit.