What is the bitterlich method?
Bitterlich’s method is based on the relationship between the basal area of a tree and the basal area per acre that this tree represents. This means that a tree with 12”diameter in a circular plot with 33’radius represents a basal area of 10 sq. ft per acre. The factor of 10 is called the Basal Area Factor, or BAF.
How do you use a BAF prism?
Hold prism (not your eye) over the selected point at a comfortable distance from the eye, with the long side horizontal. Hold prism with right hand by lower part of the thicker edge. 2. With one eye closed, point with the upper part of the prism so as to divide the tree in question at breast height.
How do you find the TPA in a variable radius plot?
Expansion factor = Plot size denominator / Plots 2. Add up the total number of trees for all the plots in the stand. 3. Multiply the total number of plot trees by the expansion factor to determine total TPA for the stand.
What is a prism used for in forestry?
The wedge prism is primarily used in a similar manner as an angle gauge in variable-radius plot sampling. In this type of sampling, the wedge prism is used to estimate basal area of a group of trees by counting trees which are “in” or “out” of a plot centered on a single point.
How do you use Relaskop?
The relaskop adjusts for slope when measuring diameters at any height above the ground. When measuring a diameter, take two measurements at right angles (90 degrees) to each other. Use the relaskop for abnormal diameters by shooting above or below DBH and adjusting for taper.
How do you use Relascope?
The Relascope is used by looking through the hole in the front of the instrument. When users look through this hole they will see several scales that are used for different measurements on the bottom half of their view, and on the top half they will see the tree that they are looking at.
What is plot radius factor?
A standard plot radius factor was used to determine limiting distance to the center of a tree, and is computed by 8.696/SQR(BAF). A corrected PRF subtracts 1/24 (0.041666) from the standard plot radius factor.
What is variable radius plot sampling?
Variable-radius plots (VRPs), also referred to as point sampling or prism cruising, rely on the relationship between the diameter at breast height (DBH) of observed trees and the distance between those trees and an observer who stands at plot center.
What is variable radius?
Variable radius fillets are curved surfaces defined according to a variable radius. A variable radius corner means that at least two different constant radii are applied to two entire edges.
How do you use a Relascope?
How does a diameter tape work?
How Does an OD Tape Work? An OD tape is sometimes called a “Pi tape.” To use an OD tape to determine the diameter, you actually wrap the tape around the circumference of the pipe. The tape has the formula for the circumference of a circle backed into the measurements on the tape.
How do you use Haga altimeter?
Using a Haga to determine tree height:
- Select a distance, preferably 15, 20, 25, or 30 meters away from the tree, where the required point on the tree (e.g. tree tip) can be seen.
- Select the appropriate distance scale on the rotating rod.
- Release the pointer by pressing the button on the side of the instrument.
What is Bitterlich sampling?
It is some times also referred to point sampling, horizontal point sampling, variable plot sampling, angle count technique, prism cruising, angle gauge sampling, and simply Bitterlich sampling.
How do you choose the basal area factor in Bitterlich sampling?
The choice of the basal area factor (\\ (k\\)) in Bitterlich sampling is equivalent to the choice of plot size for fixed radius plot sampling. The criteria to be considered in the choice of basal area factor are visibility in the stand and average number of sample trees desired at a sample point.
What is horizontal variable radius plot sampling?
The use of horizontal variable radius plot sampling, also known as horizontal point sampling, is widely used in operational forest inventory in North America (Iles 2003, p. 495). In this approach, plots are based on the area pro- jected around a tree rather than the area around a sampling point.
What is the sampling intensity of the horizontal line sampling method?
The sampling intensity of the horizontal line sampling method remains an understudied issue in terms of appro- priate number of sampling lines, length of individual lines and the appropriate angle gauge to use in a given stand type. Beers and Miller (1976) recommend a line length of 1–2 chains (20.12–40.14 m).