Where we are headed
Map reading and compass use Species identification (FOR 219) Tree measurement (diameters and heights) Defect recognition and determination Quality determination (grading) Use of timber cruising tools Traverses Elementary use of aerial photography
Compass and GPS Loggers tape Dendrometer and Hypsometer Increment Borer Flagging and Stakes Maps, Aerial Photos, Cruising plan Axe and paint Data recording device (electronic or manual) Prism Calculator
Boots Chaps First aid kit Hard Hat Safety glasses Vest Radio Water supply
Part 1 - Diameter
An instrument used to measure trees
Diameter Breast Height Average diameter at 4.5 feet (1.4 meters) Easiest to measure, less taper, not height of cut Outside bark Uphill side of tree
basal area of a forest stand can be found by adding the basal areas of all of the trees in an area and dividing by the area of land in which the trees were measured. Basal area is generally expressed as ft 2 /acre
Held 25” from eye
One-inch diameter class examples 5-inch class = 4.6 to 5.5 inches 9-inch class = 8.6 to 9.5 inches Two-inch diameter class examples 12-inch class = 11.0 to 12.9 inches 14-inch class = 13.0 to 14.9 inches
Needed for tree form, taper, and volume. Can determine merchantable height. Need to be able to do this easily, quickly and safely.
Review
To use the one-half diameter method, make two marks opposite each other on the stem at 4.5 feet. Measure the distance between the marks with the diameter tape and double the measurement to determine DBH. Repeat the process for the other tree.
If these measurements are at equal distance from 4.5 feet, average A and C to arrive at DBH measurement. If point A and point C are at unequal distances from 4.5 feet, interpolate the distances to arrive at DBH measurement
a.Measure diameter above DBH where shape is normal, point A in diagram at right. b.Measure height to the point where DBH was taken. c.Determine average taper from comparable trees of the same species in immediate area. d.Interpolate DBH measurement "C" based on diameter measurement "A", the estimated average taper, and length "B".
For split trees, measure DBH with calipers or use the one-half diameter technique. Make two marks opposite each other on the stem at 4.5 feet. Measure the distance between the two marks with a diameter tape and double the measurement to determine the diameter
Since DBH includes bark you must estimate what the measurement would be including the missing bark. If all bark is missing, try to get a measure from similar nearby trees.
-- Diameter tape (D-Tape). Adjust the tape at a normally rounded position to allow for the catface portion missing. If the tape is not adjusted but is pulled tight, the tape will be straight across the missing portion and the diameter read will be less than it should be. -- Calipers. Measure DBH at right angle to catface. -- One-half Diameter Technique. Use this technique on trees growing together.
Crown Width
Highly correlated to tree vigor and other measurable parameters. Helps predict response from silviculture treatments like thinning or fertilization Useful in ecological studies
1.Average of Maximum and Minimum diameters 2.Average of Maximum diameter and the one perpendicular to that axis 3.Average of some random width and the perpendicular axis width 4.For highly irregular crowns more than 2 measurements may be averaged
How, What, Where, Why
Easily seen from a distance Type of mark may be distinctive for type of tree (i.e. diagonal line for boundary, horizontal line for pulp tree, etc. Boundary trees marks visible from three sides. Boundary trees visible from each other.
Survives after operation Downhill side Remove loose bark, etc first Paint into bark furrows and between root swellings Include tree and soil Law enforcement ramifications
Black paint used first to hide old paint All forest service paint contains tracers - Thus USFS paint requires tight supervision, inventory, security.
May be used when need to identify this tree is temporary or short lived.
Cruise ID number painted on tree Cruiser initials also Paint applied towards plot center if part of sample point.