Where we are headed

Timber Cruiser

Map reading and compass useSpecies identification (FOR 219)Tree measurement (diameters and heights)Defect recognition and determinationQuality determination (grading)Use of timber cruising toolsTraversesElementary use of aerial photography

Timber Cruiser Skill Set

Compass and GPSLoggers tapeDendrometer and HypsometerIncrement BorerFlagging and StakesMaps, Aerial Photos, Cruising planAxe and paintData recording device (electronic or manual)PrismCalculator

Field Equipment

BootsChapsFirst aid kitHard HatSafety glassesVestRadioWater supply

Safety Equipment

Part 1 - Diameter

Measuring Trees

An instrument used to measure trees

Dendrometer

Diameter Breast HeightAverage diameter at 4.5 feet (1.4 meters)

Easiest to measure, less taper, not height of cutOutside barkUphill side of tree

DBH

Measuring trees

Radius:

Circumference:

Area:

Basal Area(ft2)= .005454 DBH2

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 ft2/acre

Biltmore Stick

Held 25” from eye

Tree diameters – Oblong Boles

Calipers

Using Calipers

Sector Fork

D-Tape

D-Tape scale

Tape must be perpendicular to tree

One-inch diameter class examples5-inch class = 4.6 to 5.5 inches9-inch class = 8.6 to 9.5 inches

Two-inch diameter class examples12-inch class = 11.0 to 12.9 inches14-inch class = 13.0 to 14.9 inches

Diameter Classes

Can average DBH for stand and/or by species

After calculating Basal Areas for all trees. You can average the BA for the stand and/or by species

The square root of the mean BA/.005454 is the quadratic mean diameter or the diameter of the tree of mean basal area.

Summarizing

Needed for tree form, taper, and volume.

Can determine merchantable height.

Need to be able to do this easily, quickly and safely.

Upper Stem Diameters

Spiegel Relaskop

Relaskop screen

Relaskop compensates for angles

Wheeler Pentaprism – optical caliper

Review

Measuring Tree Diameters

Measuring Problem Trees

Tree diameters – Oblong Boles

DBH Measurement for irregular stems

D-Tape for leaning tree

Trees growing togetherTo 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.

Tree Growing on or around an object

If these measurements are at equal distance from 4.5 feet, average A and C to arrive at DBH measurement.

Abnormality at DBHIf point A and point C are at unequal distances from 4.5 feet, interpolate the distances to arrive at DBH measurement

Butt Swell

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".

Broken Tree/Severed Tree

Down Tree

Split TreeFor 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

Missing Bark

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.

Missing Bark – use Bark GaugeAdd thickness of bark to missing region

Catfaces-- 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

Additional Measurements

Highly correlated to tree vigor and other measurable parameters.

Helps predict response from silviculture treatments like thinning or fertilization

Useful in ecological studies

Crown Diameter

How to MeasureCrown Diameter

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

Timber MarkingHow, What, Where, Why

Eye Level MarkEasily seen from a distanceType 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.

Stump MarkSurvives after operationDownhill sideRemove loose bark, etc firstPaint into bark furrows and between root

swellingsInclude tree and soilLaw enforcement ramifications

Canceling Prior WorkBlack paint used first to hide old paint

All forest service paint contains tracers - Thus USFS paint requires tight supervision, inventory, security.

FlaggingMay be used when need to identify this tree is

temporary or short lived.

Tree Numbering – Permanent PlotsCruise ID number painted on treeCruiser initials alsoPaint applied towards plot center if part of

sample point.

Paint Colors