1. Forestry Measurements
Written by:
Heather Dombroski
July 2005

2. Pre-reading Website reading
After your finished take a look at “Facts About Today's Michigan Forests”

3. Let’s Review What are our most popular trees?
Who owns the most forested land in Michigan?
Where is the majority of our forest?
Why are forests important?

4. Pacing How far is one step? that is your pace
Everyone's will be different, you must remember yours
We’ll measure out 1 chain (66ft)
You will practice walking this distance to get an average pace measure

5. Percent Crown Coverage
From a point looking up, what % of the sky is covered (no light gets through)
Our measurement tool is called a densitometer
We will be
making our own
and using them
outside

6. Densitometer
Hold it above your face just an inch or so, you see several squares, their either covered or not
Count the ones covered
Multiply this number by 4 to get 100% canopy cover
From spot one move 5 paces rerecord, repeat until you have 8 readings
This represents 25%

7. What is a Board Foot? 12”long X 12”wide by 1” thick
This is the measurement marketable timber is sold by (144 cubic inches per bd ft)
So if we have a 2X4 that’s 8ft long, how many Bd ft is that?
2inch x 4inch (8ft x 12in/ft) = 768 cubic/in
768/144 = 5.33 bd ft
12” 1”
12”

8. Practicing Bd ft
We cut a 1 ½ x 8 on our sawmill in the bullpen, its 10ft long. What’s the bd ft?
1.5x8 (10ft x 12in/ft) = 1440 cubic ft
1440/144 = 10 Bd Ft

9. Diameter at Breast Height
This is 4 ½ feet from the level ground
This helps us decide marketable timber
The sectional area is also called Basal area
We will use both;
diameter tape and
the Biltmore stick

10. Height in logs or bolts
Logs - 16ft marketable section of a hardwood tree
Bolts –8ft marketable section of a coniferous tree
This is measured until a break in the bole (trunk) on hardwoods or 8” diameter
And measured up to a 4” diameter on pines

11. Measuring Marketable Timber
We use # of logs and DBH to figure Marketable timber or volume
By looking at the “How much Lumber is in that Tree” handout we see there is more than one way to figure this amount

12. Aging Trees Taking a core sample
Counting sections of limbs on conifers
Tree cookies

13. Density of Trees per Acre
Usually estimates by 1/10 acre plots
Done in several random areas of a stand
These areas are then averaged
1/10 plot = a circle with a 37.2ft radius
At higher densities, the growth rates of individual trees slow down because there are more trees competing for the site's limited resources. 
37.2