Beacon Lesson Plan Library
Measuring the Merchantable Height of a Tree
Jacqueline Roberts
Bay District Schools
Description
In this activity, students learn techniques that determine the merchantable height of a tree and the number of logs a tree provides.
Standards
Florida Sunshine State Standards
MA.B.1.4.1
Uses concrete and graphic models to derive formulas for finding perimeter, area, surface area, circumference, and volume of two- and three- dimensional shapes including rectangular solids, cylinders, cones and pyramids.
MA.B.3.4.1
Solves real-world and mathematical problems involving estimates of measurements including length, time, weight/mass, temperature, money, perimeter, area, volume, and estimates the effects of measurement errors on calculations.
MA.B.4.4.1
Determines the level of accuracy and precision, including absolute and relative errors or tolerance, required in real-world measurement situations.
MA.B.4.4.2
Selects and uses appropriate instruments, technology, and techniques to measure quantities in order to achieve specified degrees of accuracy in a problem situation.
Florida Process Standards
Effective Communicators
02 Florida students communicate in English and other languages using information, concepts, prose, symbols, reports, audio and video recordings, speeches, graphic displays, and computer-based programs.
Numeric Problem Solvers
03 Florida students use numeric operations and concepts to describe, analyze, communicate, synthesize numeric data, and to identify and solve problems.
Critical and Creative Thinkers
04 Florida students use creative thinking skills to generate new ideas, make the best decision, recognize and solve problems through reasoning, interpret symbolic data, and develop efficient techniques for lifelong learning.
Materials
-Biltmore Stick with Hypsometer
-Tape measure
-Calculator
-Area to do the activity
-Copies of Tree Measurement Attachment, Diagram of Hypsometer Scale, Data Sheet, Rubrics (one per student)(see aAttached Files)
Helpful Resources:
Florida Division of Forestry - Education Department
715 W. 15th Street
Panama City, Florida
850-872-4175
Introduction to Forestry in Florida, Florida Department of Agriculture and Consumer Services, Division of Forestry Service, Tallahassee, Florida.
Florida's Forest Facts, Florida Division of Forestry, pamphlet
Preparations
1. Make copies of the documents in the attached file for students.
2. Determine where students will complete the activities and mark trees.
3. Be prepared to review the following topics:
*Pacing
*Gunther Chain.
*Use of Hypsometer
*Definition of merchantable height
*Definition of pulpwood and sawtimber
*Uses of pulpwood (paper products)
*Uses of sawtimber (lumber)
*Definition of "eyeball" observation
*Margin of error and importance of accurate estimations
Procedures
(Note: The attached file contains information which may be helpful in determining some of the information below.)
(Note: Share the handouts and rubrics with students prior to beginning this lesson. Students will need to understand how they will be assessed before beginning the activity. Once they have complete understanding, then begin the activity.)
(Note: As with the other lessons in this unit, be sure to use the vocabulary found in the first lesson of this unit called Wanted Dead or Alive....How Big Is It? By now, students should know the definitions and be able to use them accurately as they are completing the activities.)
Conduct a review of the previous lessons in this unit. Make sure each student:
1. Understands merchantable tree height is the upper limit of usable wood on a tree stem.
2. Understands that measurement of tree height is accomplished with a Merrit Hypsometer Scale which is found on a Biltmore Stick.
3. Understands that the Hypsometer is -ruler-like- in that it has increments numbering from 1 through 5. Each increment represents a sixteen foot log.
4. Understands how to -sight - height with a Hypsometer. (Continue reading for guidance.)
5. Understands how to pace a Gunther Chain.
6. Understands that to use the Hypsometer requires an individual pace a Gunther Chain (66ft) away from the tree.
7. Understands the uses of sawtimber.
8. Understands the uses of pulpwood.
9. Understands circumference.
10. Understands diameter.
11. Understands the forest industry's standard of measurement for diameter is at breast height.
12. Understands that when measuring for sawtimber an "eyeball" observation is made to determine where the upper most limit of the stem is 8 inches in diameter
13. Understands that when measuring for pulpwood an "eyeball observation is made to determine where the upper most limit of the stem is 4 inches in diameter.
14. Understands that the hypsometer must be held upright and at a distance of twenty-five inches away from the body. (This is approximately an arm length.)
15. Understands that to measure accurately the base of the hypsometer must be aligned with the bottom or base of the tree.
16. Understands that the scale is read to location (height) of ocular estimation previously established.
17. Understands the concept of margin of error.
For the remainder of the time, students demonstrate their knowledge through laboratory assessment and oral presentation. Explain the following steps and make sure students know what to do.
STUDENT ACTIVITY: (Show students the rubric prior to beginning this activity.)
1. Students work with a partner to complete this activity. (See Attached Files.)
2. Students measure the circumference of a tree at breast height.
3. Students record this on Data Sheet. (See Associated File)
4. Students divide circumference by 3.14 (Pi) to establish diameter.
5. Students record diameter on data sheet.
6. Students then determine if the tree is sawtimber or pulpwood and record this information on the data sheet.
7. Students pace a Gunther Chain (66 ft.) away from the tree. Students maintain clear sight of base and top of the tree at the end of paced chain.
8. Students estimate the merchantable height of the tree and record on data sheet.
9. Students estimate how many 16-foot logs the tree could produce.
10. Students estimate location at the top of the tree where the diameter might be 4 inches if measuring pulpwood or 8 inches if measuring saw timber.
11. Students hold Hypsometer directly in front of the body and twenty-five inches away from the body. (Twenty-five inches is approximately arm's length.)
12. Students maintain alignment of Hypsometer. The stick should be even with the base or bottom of the tree.
13. Students hold the Hypsometer steady, sighting the stick upward to the point students previously established as merchantable top of tree.
14. Students read Hypsometer scale and record to the nearest stick of pulpwood or sawtimber.
15. Students convert the number of sticks to merchantable height and record data.
16. Students compare their personal estimates with the measurements taken with the Hypsometer and record margin of error data.
17. Students share their findings with the class.
Assessments
Formativley assess students' work and oral presentations by using the
Oral Presentation and Lab Rubrics located in the attached file. This lesson does not assess all of MAB. 1.4.1 (cones and pyramids). Students may need feedback, reteaching, and additional practice since these skills are covered on the summative assessments.
Extensions
Click here to view the Beacon Unit Plan associated with this lesson. See Attached Files to download the Unit Plan Overview, Unit Assessments, and other associated files.
Web Links
Web supplement for Measuring the Merchantable Height of a Tree Florida Forests Forever
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