EXAM II                                              FR 3218/5218                              Semester II - 2004

 

            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 = 57.

 

 

(4) 1.    Which of the following is a (are) legitimate justification(s) for considering the use of two-stage or cluster sampling:

a.       improved precision over a simple random sample of the same number of units

b.      travel cost between sample units high

c.       sample units naturally clustered

d.      reduce possibility of bad systematic samples

 

(4) 2.    For the following data from a two-stage sample (three primary sample units, four secondary sample units per primary) compute

 

 

Secondary

 

Primary

 

1

2

3

4

 

1

 

3

2

5

2

 

2

 

6

5

1

3

 

3

 

2

4

1

5

 

 

 

 

 

 

(4) 3.    Answer one, but only one, of the following:

 

i.         Describe the steps in conducting a mark-recapture sample to estimate the number of red squirrels on Cloquet Forestry Center.

ii.       Describe the steps in conducting a line-intercept sample to estimate the biomass of downed, coarse woody debris in a 100-acre tract.

 

 

 

 

 

 

 

(3) 4.    What’s the difference between a composite individual tree volume table and a standard individual tree volume table?

 

 

            Which, presumably, provides more accurate estimates of individual tree volume?

 

 

(4) 5.    You have a list of 100 trees, with DBH recorded for each tree. For 20 of the 100 trees you have, in addition to DBH, merchantable height and Girard form class. The only volume table available estimates volume from DBH, merchantable height, and Girard form class. How will you estimate the volume of all 100 trees?

 

 

 

 

 

 

 

 

 

(4) 6.    Use any of the attached tables to estimate the cubic foot volume in the first 20-foot log (ignore stump and trim allowance, i.e. assume they are zero) of a 13-inch DBH, 80-foot tall tree. Be sure to clearly identify your choice of table(s).

 

 

 

 

 

 

(4) 7.    Using the taper equation (with symbols and units as defined in class):

 

           

 

            find the cubic foot volume below 50 percent of total height for a 9.5-inch DBH, 54-foot tall tree. (you will receive full credit for setting up the necessary equation; “solve” the equation for extra credit only if you have time)

 

 

 

 

 

 

 

 

(2) 8.    The coefficient of variation for observations on 1/20-acre fixed-radius plots will be approximately _____ times larger than the coefficient of variation on 1/10-acre fixed-radius plots.

a.       2.0

b.      1.7

c.       1.4

d.      1.2

 

(4) 9.    You are told to conduct a line-plot cruise in a 24-acre stand using 10, 1/10-acre fixed-radius plots. You want to use a reasonable, rectangular grid with integer (whole number) number of chain spacings. What a) distance between lines and b) distance between plots along lines would you choose? (there is more than one correct answer pair – provide one correct pair)

 

 

 

 

(3) 10.  How close to plot center must a 6-inch DBH tree be to be “in” on a 1/20-acre fixed-radius plot? What exact distance must you measure for comparison?

 

 

 

 

(3) 11.  What do stand and stock tables have in common? How do they differ?

 

 

 

 

(6) 12.  Find observations of trees per acre and basal area per acre for the following tally of trees on a 1/15-acre fixed-radius plot (e.g. there were 6, 10-inch trees tallied).

 

DBH (inches)

 

8

10

12

Number of trees tallied

 

4

6

2

 

 

 

 

 

 

 

 

 

 

 

 

(2) 13.  For variable-radius plots, as we defined them in class, plot size is directly proportional to what function of DBH?

 

 

(4) 14.  Which of the following will result in an under-count of trees at a variable-radius plot sample location:

a.       failure to account for sloping terrain

b.      keeping your eye over the sample location when using a prism

c.       a knotted string (making it too short) on your homemade angle gauge

d.      consistently sighting on trees below breast height with a prism

 

(3) 15.  How far can a 10-inch DBH tree be from the sample location and still be “in” when using a 20BAF variable-radius plot?

 

 

 

 

 

(3) 16.  Explain how to apply the mirage method of boundary overlap correction when using variable-radius plots.