# Forestry Measurements

## Presentation on theme: "Forestry Measurements"— Presentation transcript:

Forestry Measurements
Written by: Heather Dombroski July 2005

After your finished take a look at “Facts About Today's Michigan Forests”

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?

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

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

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%

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”

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

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

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

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

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

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