EXAM IV                                             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. Unless otherwise indicated, any number of multiple-choice options (including zero) may be correct responses to the question statement; circle all correct responses. Total points = 85.

 

(4) 1. Which tree dimension tends to most closely exhibit the classic sigmoidal cumulative growth pattern with a distinct inflection point and an asymptote? (one correct answer)

a.       DBH

b.      Basal area

c.       Height

d.      Board foot volume

 

(4) 2. An increment borer can be used to extract a core at breast height allowing us to measure past DBH growth for a tree. What additional tree growth information can be obtained with a complete stem analysis?

 

 

 

 

 

 

(8) 3. Fill in the blanks.

 

Age

Size

Mean Annual Increment

10 Year Periodic Annual Increment

40

60

___

 

 

 

 

2

50

___

___

 

 

 

 

___

60

___

1.5

 

 

 

(4) 4. Given the yield equation

 

            Y = 70 * A1.1 – 0.05 * A2.6

 

where Y is yield and A is age, find the age of maximum mean annual increment.

 

 

 

 

(6) 5. A stand was measured at two points in time and the following observed:

 

Basal Area per Acre (ft2)

Stems per Acre

Quadratic Mean DBH of Mortality Trees (inches)

135

400

5.0

155

350

---

 

Calculate mortality and survivor growth (in units of square feet of basal area per acre) assuming no ingrowth and no outgrowth.

 

a.       mortality (square feet per acre)

 

 

 

b.      survivor growth (square feet per acre)

 

 

 

(5) 6. Sketch the DBH distributions for a) a balanced uneven-aged stand and b) young age, medium age, and old age even-aged stands.

 

Text Box: Frequency
 

 

 

 

 

 

 

 

 

 

 

 

Text Box: Frequency
 



(12) 7. Use the data below to project the stand table ten years into the future. Assume five (5) percent mortality of trees in the 8-inch DBH class and below and stand ingrowth into the 4-inch DBH class of 60 trees per acre.

 


DBH (inches)

10 Year DBH Increment (inches)

Current Trees per Acre

4

1.2

80

6

1.8

70

8

2.2

60

10

2.1

40

12

1.9

20

 

 

 

 

 

 

 

 

 

 

 

 

 

(4) 8. Name a measure of competition or describe how competition might be assessed in a:

 

a.       distance independent individual tree growth and yield model

 

 

 

b.      distance dependent individual tree growth and yield model

 

 

(4) 9. Individual tree growth and yield models commonly predict the probability of individual tree mortality. The predicted probability may be applied deterministically or stochastically. Describe those two alternatives and identify what additional mortality component the stochastic alternative is attempting to incorporate.

 

 

(4) 10. Consider the last homework assignment. The DBH growths predicted by TWIGS (question 2.) were not completely consistent with the DBH growths assumed for the stand table projection (question 1.)? Describe how were they inconsistent?

 

 

 

 

(4) 11. What is the major disadvantage of normal and empirical yield tables when applied to managed forest stands?

 

 

 

 (5) 12. The whole stand growth and yield model for red pine in Minnesota we discussed in class predicted cubic feet per acre stand yield as:

 

            Y = 0.4085 * B * H

 

where B is basal area per acre and H is height of dominant and co-dominant trees. If you wish to predict yield at some future point in time (where B and H aren’t directly observable), how are you expected to get B and H?

            B –

 

            H –

 

(4) 13. What three aspects of thinning could you simulate using PCWTHIN? Describe your thinning objective for question 3. on the last homework?

a.       aspect 1 – type of thinning (row versus low, etc.)

b.      aspect 2 –

c.       aspect 3 –

 

d.      thinning objective –

 

 

 

 

(5) 14. How would you compute board foot volume of veneer logs in a stand whose DBH distribution is given below (fD(d) is the probability distribution function for DBH – assume you have the mathematical equation for fD(d))? Veneer logs are the butt (first) log of trees exceeding 18-inches DBH that are free of knots.

a.       What stand attribute must you first know?

 

 

b.      What would you compute using the stand attribute in a. and the probability distribution function? How would you compute it?

 

 

c.       What would you need to get board foot volume?

 

 

 

d.      What other information will you need?

 

 

 

Text Box: fD(d)
 

 

 

 

 

 

 

 

 

 

 


 (4) 15. Both the 3-PG and PnET forest ecosystem models are sometimes referred to as “Big Leaf” models. What does that imply in terms of model application assumptions? How is that a shortcoming when simulating growth of managed forest stands?

            What –

 

 

            How –

 

 

(4) 16. What silvicultural treatment(s) (not necessarily commonly applied in Lake States forestry practice) might be more appropriately evaluated using a process-based model of forest growth as opposed to a traditional growth and yield model?

a.       row thinning

b.      pruning for increased wood quality

c.       fertilization

d.      irrigation

 

(4) 17. The basic approach for predicting realized growth for both the TWIGS individual tree growth and yield model and the LINKAGES individual-based forest ecosystem model was:

 

            realized growth = potential growth * modifier

 

How do the two models differ in terms of what constitutes the modifier term?