EXAM IV                                             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.          The number preceding the question number is the point value of that particular question. Unless explicitly stated, any number of multiple-choice options (including zero) may be correct responses to the question statement; circle all correct responses. Total points = 49.

 

(4) 1. Identify each of the cumulative growth curves below as being typical of total height growth or DBH growth (circle correct answer in each panel).

 

 

 

 

 

 

 

 

 

 

 


(4) 2. For an individual tree dimension, the periodic annual increment curve:

            a. becomes like the mean annual increment curve as the period length increases

            b. becomes like the current annual increment curve as the period length increases

            c. peaks before the current annual increment curve

            d. peaks after the mean annual increment curve

 

(2) 3. As illustrated in your textbook, the asymmetry of growth rings makes the use of increment cores | stem analysis (circle one) problematic.

 

(4) 4. A 1/20-acre plot was measured at two points in time, 10 years apart. No harvesting took place in the 10 year period. The results were:

 

Tree     BA1      BA2                  Tree     BA1      BA2

    1       .17       .22                     5         --       .15

    2       .41       .56                     6         --       .18

    3       .22         --                     7       .28       .40

    4       .30       .46                     8       .31       .46

 

BA1 means tree basal area at time 1, BA2 means tree basal area at time 2 (ten years after time 1), and -- means the tree wasn’t measured at the time. Compute the components of growth in terms of basal area per acre.

            Survivor –

            Ingrowth –

            Outgrowth –

            Mortality –

 

 

 

(4) 5. The temporal patterns of growth and yield differ dramatically between even-aged and uneven-aged stands. Sketch the two patterns on the graph below and identify cutting cycle for uneven-aged and rotation age (and thinnings if you include them) for even-aged.

 

 

 

 

 

 

 

 

 

 

 

 

 


(4) 6. The DBH distribution in an even-aged stand:

            a. becomes more symmetric as the stand ages

            b. increases in spread (variability) as the stand ages

            c. is more constant in shape (through time) than that of an uneven-aged stand

            d. becomes more symmetric after a row thinning

 

(3) 7. For the yield function Y = -700 + 50 A – 0.3 A2 where Y is yield and A is age, find the age of maximum mean annual increment.

 

 

 

 

 

 

(5) 8. Given the number of trees in each DBH class and the 10-year DBH increments (inches) below, predict the future stand table in 10 years using stand table projection. Assume no stand ingrowth. Assume 2 percent of the trees in each class will die during the 10-year period. Assume no cutting.

 

DBH

Increment

Trees Per Acre

14

1.5

80

15

1.2

60

16

0.9

40

17

0.8

15

 

 

 

 

 

 

 

 

 

 

 

 

 

(2) 9. Individual tree growth and yield models often predict dimensional growth as

            realized growth = potential growth * modifier

 

What type of tree is used to characterize potential growth for:

            DBH growth ___________

            Height growth ____________

 

(2) 10. Distance independent and distance dependent individual tree growth and yield models differ primarily in terms of how they assess competitive status. Identify an example (by name) of a competition measure (from lecture or the text) used in:

            Distance independent models _______________

            Distance dependent models ________________

 

(2) 11. In what we labeled the “Clutter approach” to developing a variable-density, stand-level growth and yield model (illustrated in your text with a yellow-poplar example) one equation predicts yield from age, site quality, and density. What second equation is required to complete the model and why?

 

 

 

 

 

 

(4) 12. How do DBH distribution growth and yield models compare to individual tree and whole stand models in terms of input requirements and output detail?

 

                                                Input Requirements                               Output Detail

 

DBH distribution versus

whole stand

 

DBH distribution versus

individual tree

 

(3) 13. The probability distribution function (x = DBH):

            f(x) = 0.1 exp(-0.1 * x)

has been predicted for a stand with 400 stems per acre. Describe how you would estimate basal area per acre in the 10-inch DBH class (9.5 – 10.5) for the stand. Be specific as to how you would manipulate the probability distribution function (what mathematics you would need to apply to it) as part of the estimation.

 

 

 

 

 

 

 

 

(4) 14. Which of the following are common characteristics of "big-leaf" ecosystem models such as PnET or 3-PG?

a. distance dependent

b. based on empirical relationships rather than mechanistic processes

c. include explicit environmental drivers

d. view canopy as a single homogenous unit

 

(2) 15. One of the articles you were to read that described the 3PG model referred to the implementation “3PG-SPATIAL.” What does the “SPATIAL” specifically refer to there? (it is not sufficient to just define what the word spatial means)