This is a lesson outline developed in June 2010.
Purpose: To provide opportunities for youth to 1) learn a handy approach for determining
distance, 2) gain exposure to a variety of forest measurement equipment for determining tree
volume, 3) calculate the amount of product a tree could yield from that given volume, and 4)
determine and compare distance measurements obtained using a variety of approaches.
Secondarily, the class will expose students to forest management equipment of varying degrees
of sophistication and allow students to speculate about what future distance measuring
equipment might be like.
Materials:







Equipment for measuring tree diameter (e.g., d-tape, Biltmore stick)
Equipment for measuring tree height (e.g., clinometers, ruler, yardstick)
Equipment for measuring distance (e.g., tape measure, GPS, hip chain, laser range finder)
Clipboards
Pencils or pens
Calculators
Worksheets
1. Pacing and distance
2. Compare distance measurements
3. Tree volume and products
Activities:
1.
2.
3.
4.
5.
6.
Introduce instructors and class purpose
Ask what are some products that come from a tree
Split into small groups (3-5 per group)
Head to pacing determination course
Determine pacing factor (Steps 1and 2 in Pacing and Distance Worksheet)
Determine distance along a second course using pacing, GPS, hip chain, laser range
finder, and tape measure (Steps 1 – 5 in Compare Distance Measurements Worksheet)
7. Closing conversation: Are the distance measurements different? If so, why? Which one
is most likely to be correct? Why? How will we measure distance seven generations
from now?
8. Select a tree to measure diameter and height where it is easy to see base and top of tree
9. Measure and record tree diameter to the nearest inch (Step 1 in Tree Volume and
Products Worksheet)
10. Pace a specified distance from the tree and them measure and record tree height to the
nearest 10 feet (Step 2 in Tree Volume and Products Worksheet)
11. Determine the number of cords and board feet in the tree (Step 3A or 3B in Tree Volume
and Products Worksheet)
12. Calculate product volumes (Step 4 in Tree Volume and Products Worksheet)
Pacing and Distance Worksheet
Pacing is TWO steps: right foot to right foot or left foot to left foot, NOT one stride: right to left
foot or vice versa.
Step 1: Determine average number of paces/66 feet
_____________ Paces/chain (66’)
_____________ Paces/chain (66’)
_____________ Paces/chain (66’)
_____________
/
3
(Total paces/chain) / (# of times paced the chain)
= _________________
= average # of paces/chain
Step 2: Determine pace length (feet)
÷
66 feet
average # paces
= __________ feet
pace length
Compare Distance Measurements Worksheet
Step 1: Determine distance using your pacing factor
X
Pace length
# paces walked
= _________
Distance
Step 2: Determine distance using a Global Positioning System (GPS) receiver
GPS distance ___________________ feet
Step 3: Determine distance using a hip chain
Hip chain distance _______________ (feet) OR __________________________ (meters)
Conversion from meters to feet: 1 meter = 3.28 feet
____________________ meters x 3.28 = ____________________ feet
Step 4: Determine distance using a laser range finder
Laser range finder distance ___________ feet
Step 5: Determine distance using a tape measure
Tape measure distance _______________ feet
Discussion questions: Are the distance measurements different? If so, why? Which one is most
likely to be correct? Why? How will we measure distance seven generations from now?
Tree Volume and Products Worksheet
Timber volume is sometimes expressed in cords or board feet. A cord equals 128 ft3 of wood,
air, and bark (for example, 8 feet x 4 feet x 4 feet). A board foot is 144 in3 of wood (for
example, 12 inches x 12 inches x 1 inch). As a rough conversion, there are approximately 500
board feet in one cord.
Board foot
Cord
Step 1
Measure and record the diameter of your tree. Round each diameter measurement to the nearest
inch. As an example, trees with a diameter of 9.6 – 10.5 inches would be recorded as having a
diameter of 10 inches.
Example data
Actual
_10.7_
Your data
Rounded
__11___ Diameter (inches)
Actual
______
Rounded
_______ Diameter (inches)
A
B
Source: American Forest Foundation. http://65.109.144.97/curriculum/PreK-8_Resources/PreK8%20Guide%20Student%20Pages/Act_67_Student_Pages.pdf
Step 2
Measure and record the height of your tree. Round each height measurement to the nearest 10
feet. As an example, trees with a height of 46 – 55 feet tall would be recorded as being 50 feet
tall.
Example data
Actual
__44__
Your data
Rounded
__40___ Height (feet)
Actual
______
Rounded
_______ Height (feet)
Actual height of the person standing next to the tree ____________ feet
Height of the (A) person as measured using ruler or other device ____________ inches
Height of tree (B) as measured using ruler or other device ____________ inches
Tree height = Person’s height (feet) X Tree’s height from ruler (inches)
Person’s height from ruler (inches)
Tree height = _________________ X ____________________________ = _____________ feet
Step 3A
Use the volume Table 3A to determine number of cords from diameter and height
Number of cords ______________
Number of board feet = _______________ cords x 500 = __________ board feet
OR
Step 3B
Use the volume Table 3B to determine number of cords from diameter and height. Follow the
example below for a tree that is 40 feet tall and 11 inches in diameter (11.1 cubic feet).
Number of cords =
Number of cubic feet =
128
11.1 = 0.08 cords
128
Number of board feet = Number of cords x 500 = 0.08 x 500 = 40 board feet
Number of cords =
______________________= __________ cords
128
Number of board feet = _______________ cords x 500 = __________ board feet
Step 4
Assume that one birdhouse = 3 board feet. How many birdhouses could be produced?
Board feet = _________ birdhouses
3 board feet
Assume that one picnic table = 99 board feet. How many picnic tables could be produced?
Board feet = _________ picnic tables
99 board feet
How many toothpicks and personal checks could be produced?
7,500,000 toothpicks x ____________ cords = ____________________________ toothpicks
460,000 personal checks x ____________ cords = ____________________________ checks
Volume Table 3A (volume in cords)
Diameter
(inches)
Volume in cords when total height is
20 feet
30 feet
40 feet
50 feet
60 feet
70 feet
80 feet
90 feet
3
0.004
0.005
0.006
0.008
---
---
---
---
4
0.006
0.009
0.012
0.014
0.017
---
---
---
5
0.010
0.013
0.018
0.023
0.027
0.031
---
---
6
0.015
0.020
0.026
0.032
0.038
0.045
---
---
7
0.020
0.027
0.035
0.044
0.052
0.061
0.070
---
8
---
0.034
0.041
0.057
0.069
0.080
0.091
0.103
9
---
0.044
0.058
0.073
0.087
0.102
0.116
0.130
10
---
0.054
0.072
0.089
0.107
0.125
0.143
0.161
11
---
---
0.087
0.109
0.130
0.152
0.173
0.195
12
---
---
0.103
0.129
0.155
0.180
0.206
0.232
13
---
---
0.121
0.152
0.181
0.212
0.242
0.273
14
---
---
0.141
0.175
0.210
0.245
0.280
0.316
15
---
---
0.161
0.202
0.241
0.282
0.322
0.363
16
---
---
0.184
0.229
0.275
0.320
0.366
0.413
17
---
---
0.207
0.259
0.310
0.362
0.414
0.466
18
---
---
0.232
0.290
0.348
0.405
0.464
0.522
19
---
---
0.259
0.323
0.388
0.452
0.517
0.581
20
---
---
0.287
0.358
0.430
0.502
0.573
0.645
21
---
---
---
0.395
0.473
0.552
0.631
0.710
22
---
---
---
0.433
0.520
0.606
0.693
0.780
23
---
---
---
0.473
0.568
0.663
0.757
0.852
24
---
---
---
0.516
0.619
0.722
0.828
0.930
25
---
---
---
0.559
0.664
0.781
0.898
1.008
Volume Table 3B (volume in cubic feet)
Diameter
(inches)
Cubic foot volume when total height is
20 feet
30 feet
40 feet
50 feet
60 feet
70 feet
80 feet
90 feet
3
0.5
0.6
0.8
1.0
---
---
---
---
4
0.8
1.1
1.5
1.8
2.2
---
---
---
5
1.3
1.7
2.3
2.9
3.4
4.0
---
---
6
1.9
2.5
3.3
4.1
4.9
5.8
---
---
7
2.6
3.4
4.5
5.6
6.7
7.8
9.0
---
8
---
4.4
5.3
7.3
8.8
10.3
11.7
13.2
9
---
5.6
7.4
9.3
11.1
13.0
14.9
16.7
10
---
6.9
9.2
11.4
13.7
16.0
18.3
20.6
11
---
---
11.1
13.9
16.6
19.4
22.2
24.9
12
---
---
13.2
16.5
19.8
23.1
26.4
29.7
13
---
---
15.5
19.4
23.2
27.1
31.0
34.9
14
---
---
18.0
22.4
26.9
31.4
35.9
40.4
15
---
---
20.6
25.8
30.9
36.1
41.2
46.4
16
---
---
23.5
29.3
35.2
41.0
46.9
52.8
17
---
---
26.5
33.1
39.7
46.3
53.0
59.6
18
---
---
29.7
37.1
44.5
51.9
59.4
66.8
19
---
---
33.1
41.3
49.6
57.9
66.2
74.4
20
---
---
36.7
45.8
55.0
64.2
73.3
82.5
21
---
---
---
50.5
60.6
70.7
80.8
90.9
22
---
---
---
55.4
66.5
77.6
88.7
99.8
23
---
---
---
60.6
72.7
84.8
96.9
109
24
---
---
---
66.0
79.2
92.4
106
119
25
---
---
---
71.6
85.0
100
115
129