4-H Forestry Project No. 7

Measuring Standing Sawtimber

One of the most important aspects of forestry is growing a crop of trees. That's right; trees are a crop. However, a crop of trees is measured and sold in a different way than are the crops familiar to most of us. Soybeans are sold by the bushel, and cotton is sold by the pound or bale. Farmers receive a certain amount, depending on the markets, for each bushel or pound they sell. Have you ever wondered how a tree farmer measures his crop of trees and how these trees are sold?

Lumber is bought and sold by the board foot. A board foot is "a unit of lumber measurement equal to one foot square by one inch thick."

Board foot volume in a piece of wood is determined by length in feet x width in inches x thickness in inches ÷ 12.

Board foot is also the term used to measure and express the amount of wood in trees. To find the board foot volume of a tree, the diameter and merchantable (usable) height must be measured. Standing timber is bought and sold in increments of one thousand board feet (MBF). For example, a tree farmer might have 50 MBF of pine sawtimber for sale.

Selling timber is a business proposition, so it is important tree farmers know how many board feet of sawtimber they have. To determine timber volumes, farmers must measure their trees. Otherwise, they would not know the value of their timber crops. Measuring timber is not difficult to learn and is one of the most important skills landowners should possess.

Project References

1. Know Your Trees, Publication 146, Mississippi Cooperative Extension Service.
2. Measure, Don't Guess, Publication 229, Mississippi Cooperative Extension Service.
3. Construction and Use of Tree Scale (Biltmore) Stick, Mississippi Cooperative Extension Service MTN 1 A.
4. Forestry Terms for Landowners, Publication 1250, Mississippi Cooperative Extension Service.
5. Lumber and Wood Products Literature, National Forest Products Association.

1. A tree scale stick (Biltmore Stick) Doyle Scale.
2. A tape measure or a piece of nonstretch string 66 feet long.
3. Notebook and pencil.

Sources of Help and Information

1. County Extension agent or 4-H youth agent.
2. County forester, Mississippi Forestry Commission.
3. District conservationist, Natural Resources Conservation Service, U.S. Department of Agriculture.
4. District ranger, Forest Service, U.S. Department of Agriculture.
5. Foresters with local forest industries.
6. Consulting foresters, self-employed.
7. Park managers, Department of Wildlife, Fisheries, and Parks.

Instructions

Tree diameter is the first measurement required in measuring timber. Take this measurement at 41/2 feet above ground on the uphill side of the tree. This measurement is known by foresters as DBH (diameter breast height) and is measured in inches.

With a measuring tape, measure 41/2 feet from the ground and see where it falls on your body. For many people it is the second button down from the shirt collar. Determine where it is on you and use this mark as a guide in measuring diameters.

Dendrometers are instruments used to measure tree diameters. There are many types of dendrometers, but one of the easiest to use is the Biltmore Stick, which is a straight wooden stick graduated for direct readings of DBH. A Doyle Rule tree scale stick will be used in this project because the Doyle Rule is the legal volume rule in Mississippi.

Use the flat side of the stick, indicated "Diameter of Tree (inches)." This side is the Biltmore Stick. Hold the stick level at 25 inches from the eye, against the tree at 41/2 feet above the ground (use the DBH mark you found earlier for this measurement). You will have to measure and practice holding the stick at the 25-inch distance from your eye. With the stick placed against the tree, close one eye and sight at the left or zero end. This end and the tree bark should be in the same line. Move your eye across the stick to the right-hand edge of the tree. Be sure not to move your head, only your eye. Read the tree diameter to the nearest inch where the right side of the tree crosses the stick.

Measuring Tree Height

The usable tree height is the second measurement used to find board foot volume. Hypsometers are instruments foresters use to measure tree heights. Many different types of height-measuring devices are available. The Merritt hypsometer is a linear scale imprinted on one face of the tree scale stick you used in finding tree diameters. You can use this same tree scale stick to find both your diameter and tree height.

To measure the merchantable (usable) length of a standing tree, you must first measure out 66 feet from the base of the tree. You can use a tape measure or mark a length of nonstretch string 66 feet to get this distance. With a little practice you will learn how to pace this distance. Always be sure you can see the entire length of the tree. Hold the stick vertical to the ground with the "number of 16-foot logs" side facing you and the zero end pointed toward the ground. Holding the stick in this position 25 inches from your eye, sight the zero end to appear to rest on the stump height of the tree. Then without moving your head, run your eye up the stick to the point where the top of the last merchantable log would be cut. The minimum top diameter of logs is 8 inches. Read the number of 16-foot logs that can be cut from the tree to the nearest one-half log (8 feet). The Merritt hypsometer scale is marked in 16-foot logs, so you will have to estimate the half logs. If the top of the last merchantable log falls halfway between two 16-foot log readings, then add one-half log to the reading.

Determining Tree Volume

Volume tables determine the volume of wood in a standing tree based on DBH and merchantable height measurements. A volume table is printed on the side of your tree scale stick on the Biltmore Stick side. After you measure the diameter and determine merchantable height, you can read across and down on the tree scale stick to find the volume of the tree. For example, if the DBH is measured to be 18 inches and the merchantable height three 16-foot logs, the volume would be 230 board feet (Doyle Rule).

Most volume tables give tree volumes in one-half log (8-foot) lengths, but the volume table on the tree scale stick is based on 16-foot logs. Therefore, you will have to figure the volumes for trees measured to the nearest one-half log. For example, if you measured an 18-inch DBH tree with 31/2 logs, the volume would be 247 board feet.

An 18-inch DBH tree with 4 logs has.......265 bd ft
An 18-inch DBH tree with 3 logs has.......230 bd ft
The difference is the volume of one log.....35 bd ft

35 bd ft ÷ 2 = 17.5, rounded off to 17 bd ft for 1/2 log

Therefore,
an 18-inch DBH tree with 3 logs has........230 bd ft
one-half an 18-inch log has....................17 bd ft
  So, the total volume of the tree is.........247 bd ft

Volume tables listed on tree scale sticks are sometimes based on different Tree Form Classes (tree taper) and may not all have the same volume figures. The standard Form Class most often used is 78. You can use whatever volumes your Doyle tree scale stick has.

Measuring Standing Sawtimber

1. Contact a local forester for help in obtaining a Tree Scale Stick (Doyle Rule).
2. Locate an area with suitable sawtimber trees to measure. Trees must be at least 10 inches DBH, with one 16-foot log and have a minimum top diameter of 8 inches. Your own yard may have enough suitable trees, or your family may have land with sawtimber trees. State parks and national forests are ideal areas. If you have trouble locating suitable trees, get help from a local forester or Extension agent.
3. Measure the DBH and merchantable height (to the nearest one-half log) of 20 different sawtimber trees and enter the measurements on the record sheet. Be sure to measure different species of trees. Try to measure several species of both pine and hardwood trees.
4. Using the volume table on your tree scale stick, find the board foot volumes of each tree and enter this volume in your record sheet. Remember. You will have to determine the volumes of trees with one-half logs.
5. After you have measured and recorded the information on all 20 trees, total the board foot volumes of all the pine and hardwood trees. Pine and hardwood volumes are recorded separately because they are usually sold separately. Divide your total tree volumes by 1,000 board feet to get MBF.
6. Contact a local forester or Extension agent and find out what the current average stumpage price is for pine and hardwood sawtimber. Enter this information on the record sheet. Stumpage is the value of trees as they stand in the woods uncut (on the stump). Timber buyers purchase standing sawtimber by the MBF, so stumpage values will be per MBF.
7. Multiply the pine and hardwood volumes (MBF) by the current average stumpage prices. This will give you the value of the trees you have measured. The pine and hardwood stumpage prices are different because pine and hardwood are used to make different wood products. The value and demand of these products determine the stumpage prices.
8. If you borrowed a tree scale stick, be sure to return it to the owner immediately after you finish measuring your trees and recording your volumes.
9. If possible, get a forester to check your tree measurements and answer any questions you may have. Ask the forester to sign your record sheet when your project has been completed.
10. Have your adult 4-H leader check your project and sign your record sheet. Include the record sheet in your 4-H member's record. Save the project sheet and other materials as future references as you continue in other 4 H Forestry projects.

4-H Forestry Project Record No. 7
Measuring Standing Sawtimber

Your full name_____________________________Your age________

Grade in school______No. years in 4-H______Date of birth______________

Your parent/guardian's name_________________________________________________

Your address_________________________________________County_________________

Name of club________________________Adult leader's name______________________

1. When did you measure your trees? (month)_______(day)_______(year)_________

2. Describe in detail the location of the area where you measured your trees. Include number of miles, direction, town or city, and county.
___________________________________________________________________________________________
___________________________________________________________________________________________

Example: On John Doe's farm near the Hickory Grove Community, 6 miles north of Grenada, Mississippi,in Grenada County.

3. List the different trees you measured and enter the species, DBH, merchantable height, and board foot volume measurements on the the back page of this project guide. Calculate the total board foot volumes for both pine and hardwood species.

4. How many different species did you measure?

5. What is the current average sawtimber stumpage price (Doyle Rule) for your area? (Example: $350 /MBF)
Pine sawtimber $___________ / MBF    Hardwood sawtimber $___________ / MBF

6. Whom did you contact for help in finding the current average stumpage prices for sawtimber?

7. Where did he/she find the stumpage prices he/she gave you?

8. Calculate the current stumpage value for the trees you measured.

Example: Pine	(MBF) 4.7	x $350	= $1,645
Pine volume	(MBF)______	x stumpage price($)____________	= $_____________
Hardwood volume	(MBF)_______	x stumpage price($)_____________	= $________
		Total value	= $__________

9. Which species group (pine or hardwood) had the highest stumpage prices?___________________

10. What reasons can you give for the differences in stumpage prices?_____________________________
____________________________________________________________________________________

11. Were you surprised at the value of the trees you measured?_____ Why?_____________________
_________________________________________________________________________________

12. List five wood products that can be made from trees like the ones you measured.

	Pine	Hardwood
Example:	Plywood	Baseball bats
	___________________	___________________
	___________________	___________________
	___________________	___________________
	___________________	___________________
	___________________	___________________
	___________________	___________________

13. Where did you get the tree scale stick you used to measure the trees?____________________
_____________________________________________________________________________

14. List two other tree scales besides the Doyle Scale that are used to determine Board Foot Volumes._______________________________________________________________________
______________________________________________________________________________

15. What other types of dendrometers do foresters use to measure tree diameters?
______________________________________________________________________________

16. Name two hypsometers (other than the Merritt hypsometer) used to measure tree heights.
______________________________________________________________________________

17. What sources of help and information did you consult on this project?
_______________________________________________________________________________

18. Write any suggestions you have on how this project could be improved.
_______________________________________________________________________________
_______________________________________________________________________________

As a forester, I have checked these Standing Tree Measurements and found them to be in accordance with proper forest measurement techniques.

	_____________________________
	Forester

As an adult 4-H leader, I have checked this Measuring Standing Sawtimber Project and Record and found it to be completed satisfactorily.

	______________________________
	4-H Leader

Total board foot volume
   Thousand board feet (MBF) to nearest tenth
   (Example: 4,680 ÷ 1,000 = 4.680 MBF or 4.7 MBF)

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Publication 1473
Extension Service of Mississippi State University, cooperating with U.S. Department of Agriculture. Published in furtherance of Acts of Congress, May 8 and June 30, 1914. Ronald A. Brown, Director

This document may be copied and distributed for nonprofit educational purposes provided that credit is given to the Mississippi State University Extension Service.