Exam 3                                                 FR 3218/5218                            Semester II – 2002

 

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. A good strategy would be to go through and answer/set up as much of each question (especially the high point value questions) as you can and then go back to fill in details.

            The number preceding the question number is the point value of that particular question. Total points = 58.

 

(10) 1. (Homework 5, Q1) Five (5) trees were tallied on one (1), 20BAF plot. The DBHs of these trees were:

            6,8,10,6,8

What are the observations of a. basal area per acre and b. trees per acre for the plot? Be sure to label your answers.

 

 

 

 

 

(8) 2. (Homework 5, Q4) Double sampling with variable radius plots (25BAF) was used to cruise the timber in an aspen stand. Fifteen (15) plots total were taken, with trees measured on two (2) plots. The total number of trees tallied across all 15 plots was 54. The trees measured on the two plots were (BA = tree basal area):

            Plot      Tree     DBH    BA       Volume (ft3)

            5          1          10        0.54     10

            5          2          8          0.35     8

            5          3          12        0.79     20

            11        1          10        0.54     12

            11        2          12        0.79     16

 

Estimate volume per acre for the cruise.

 

 

 

 

 

 

(4) 3. Describe how the sampling with partial replacement (SPR) design differs from the continuous forest inventory (CFI) design (two designs used when interest lies in forest change).

 

 

 

 

 

(4) 4. You are implementing a 3P sampling effort on a timber sale where you have guessed timber sale volume to be 70000 board feet and you have been told to sample/measure 50 trees.

a.       You should generate random numbers between 1 and ________.

b.      You visit a tree whose “guessed volume” is 400 board feet. The random number generated for this tree is 369. Should you sample/measure the tree?

 

 

 

(4) 5. When conducting regeneration surveys, the difference between the quadrat and fixed-plot-size methods is that:

a.       quadrats assess density, while fixed-size plots assess stocking

b.      quadrats assess stocking, while fixed-size plots assess density

c.       quadrats allow the forester to map the stand, fixed-size plots don’t

d.      quadrats favor taller trees over smaller trees

 

(8) 6. (Homework 6, Q1) Two (2) dominant trees were selected for assessing site quality using site index in a balsam fir stand. The trees were 42 and 48 years old and 46 and 50 feet tall, respectively. You can’t find a published site index equation for balsam fir but your boss long ago collected dominant height and age data across a range of balsam fir stands and found the relation:

            ln H = 3.6 – 20 (1/A)

where H is height and A is age. Develop a base age 50 anamorphic site index equation from your boss’ height/age equation and estimate site index for your stand.

 

 

 

 

 

 

 

 

 

(4) 7. You need to evaluate suitability of a recently abandoned farm field for planting white spruce (i.e. you need to assess site quality for white spruce on the land). What method would you use and what would the method require that you find in the literature and measure in the field?

 

 

 

 

 

 

 

 

(4) 8. Your organization’s “Field Forester’s Handbook” lists the following crown competition factor and tree area ratio equations for a particular species:

           

where N is trees per acre, D is DBH, and the sums are over trees on an acre. Upon taking plots in a stand dominated by this species you find:

            trees per acre = 150

            basal area per acre = 125 square feet

           

 

Use the information from the “Field Forester’s Handbook” to estimate stocking percent for the stand.

 

 

 

 

 

 

 

 

(8) 9. (Homework 6, Q2) The boundary line for the size/density relation for a species of interest is:

            log10 N = 4.398 – 1.6 log10 Dq

where N is trees per acre and Dq is quadratic mean DBH. You have a stand of this species you wish to derive a thinning schedule for. The upper and lower management lines are to be set at 50% and 40%, respectively. Planting density was 600 trees per acre. Compute basal area per acre (G) before and after the first thin given the thinning is “from below” with a Dafter/Dbefore of 1.05.

            a. G immediately before first thin

 

            b. G immediately after the first thin

 

 

 

 

 

 

 

 

 

 

 

(4) 10. (Homework 6, Q4) You are supposed to “clean” (thin) an upland oak stand using the standard stocking chart approach. The stand currently has 275 trees per acre and 105 square feet per acre. Basal area per acre after the cleaning is to be 80 square feet per acre. Trees per acre after the cleaning will be (using the chart below):

            a. 155

            b. 175

            c. 200

            d. 225

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Equation sheet: