NRM 340 – Exam #2 Name: ______

1.  You have cruised a white spruce forest in interior Alaska using a BAF of 10 on 30 sample points. Your tree tally was 360. Data by diameter and height class are given below:

Height (ft.)

Dbh (in.) / 30 / 40 / 50 / 60 / 70 / Total
8 / 21 / 4 / 25
10 / 24 / 36 / 10 / 70
12 / 20 / 78 / 37 / 135
14 / 5 / 22 / 38 / 15 / 80
16 / 10 / 40 / 50
Total / 45 / 65 / 110 / 85 / 55 / 360

Additionally, you are given a volume factors table with relevant entries for the above inventory data:

Height (ft.)

dbh (in.) / 30 / 40 / 50 / 60 / 70
8 / 109 / 143
10 / 117 / 150 / 183
12 / 152 / 186 / 219
14 / 152 / 186 / 219 / 253
16 / 218 / 252


Calculate (show your work):

a.  Basal area per acre

b.  Trees per acre

c.  Volume per acre (cubic feet) using the volume-factor approach. Remember that you calculate volume per acre by summing the products of ni*VFi and dividing that sum by the number of sample points (np).

2.  There are ____ satellites in the GPS constellation. You need at least ____ satellites to determine your exact position.

3.  What is the difference between raster and vector data in a GIS?

4.  Match the following terms with the correct definition:

a.  benchmark

b.  backsight

c.  foresight

d.  turning point

____ is a temporary benchmark upon which foresight and backsight readings are taken for the purpose of continuing the line of levels.

____ is a permanent object whose elevation above sea level, or above an assumed datum, is known and to which all elevations on a particular survey are referenced.

____ is a rod reading taken on any point, the elevation of which is to be determined.

____ is a rod reading taken on a point of known elevation.

5.  At what height (in feet) is dbh measured?

6.  What is the difference between a dendrometer and a hypsometer?

7.  Determine total tree height from each of the following sets of measurements:

a.  horizontal distance is 75 ft.; sighting at base is –5 degrees; sighting at top is +45 degrees

b.  horizontal distance is 75 ft.; sighting at base is +5 degrees; sighting at top is +45 degrees

c.  horizontal distance is 100 ft.; sighting at base is +5 percent; sighting at top is 42 percent

8.  Compute the volume (in standard cords) of the following stacks of wood:

a.  10 ft x 4 ft x 8 ft

b.  40 ft x 20 ft x 16 ft

9.  How many cubic feet are in one standard cord of wood?

10.  Compute the total volume (in board feet) and total values of these items of lumber:

a.  100 pieces of 2 in x 4 in x 8 ft @ $150 per MBF

b.  300 pieces of 4 in x 4 in x 10 ft @ $235 per MBF

11.  What is the per-acre expansion factor (EF) for 1/5-acre fixed-radius plots?

12.  We want to design a 20 percent line-plot cruise for a 112-acre tract using 1/10-acre sample plots. Given the following formulas:

·  Sample area (Ap) = total area (A) * cruise intensity (P)

·  Number of plots (n) = Ap / plot area (a)

Calculate:

a.  Sample area

b.  Number of plots needed

13.  The following volume data were computed from 15 1/5-acre line-cruise plots on a 34-acre tract:

Plot / Volume (ft3/plot) / Plot / Volume (ft3/plot) / Plot / Volume (ft3/plot)
1 / 500 / 6 / 415 / 11 / 470
2 / 710 / 7 / 310 / 12 / 545
3 / 425 / 8 / 200 / 13 / 450
4 / 900 / 9 / 490 / 14 / 605
5 / 610 / 10 / 600 / 15 / 510

Calculate:

a.  The estimated volume per acre

b.  The estimated volume for the entire tract

14.  Match the following terms with the correct definition:

a.  dominant

b.  codominant

c.  intermediate

d.  suppressed

____ trees with crowns either below or extending into the general level of the crown cover and receiving little direct light from above and none from the sides.

____ trees with crowns extending above the general level of the crown cover and receiving full light from above and partly from the side.

____ trees with crowns entirely below the general level of the crown cover and receiving no direct light.

____ trees with crowns forming the general level of the crown cover and receiving full light from above but little from the sides.

15.  What is the difference between single-entry and multiple-entry volume equations?

16.  Compute the volume (in cubic feet) for the following log using Huber’s volume equations. Remember Huber’s equation is (B1/2 x L). The midpoint diameter of the log is 10.0 in and the log length is 16 ft.

17.  What is a log rule?