Units of measurement, symbols, significant digits and rounding off
1.1 Units of measurement and symbols
1.2 Significant digits
1.3 Rounding off
1.4 Bias, accuracy and precision
Individual Trees and Logs
2.1 Bole characteristics
2.1.1 Diameter
2.1.2 Height
2.1.3 Bark thickness
2.1.4 Volume
2.1.5 Stem form and taper
2.2 Log characteristics
2.2.1 Diameter
2.2.2 Length
2.2.3 Volume
2.2.4 Weight
2.2.5 Allowance for defect
2.3 Crown characteristics
2.3.1 Width
2.3.2 Depth
2.3.3 Surface area
2.3.4 Volume
2.3.5 Biomass
2.4 Stem analysis
Groups of Trees (Stands)
3.1 Number of trees
3.2 Diameter
3.3 Basal area
3.3.1 Fixed-area plots
3.3.2 Angle count sampling
3.3.3 Advantages and disadvantages of angle count sampling
3.4 Height
3.4.1 Mean height
3.4.2 Predominant height, top height, dominant height
3.4.3 Stand height curve
3.5 Volume
3.6 Crown closure
3.7 Crown biomass
3.8 Growth and increment
References
Appendix 1: Checklist of equipment and materials

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2.2.1 DIAMETER

  • Measure in whole centimetres (commonly rounded down) unless a higher precision of measurement is expressly required (e.g. research).

  • When using a scale ruler (at the log ends) or calipers, measure diameter along two axes aligned perpendicular to each other, and average. Measurement along one axis only may be appropriate where highly accurate volumes of individual logs is not required.

  • Differentiate between butt logs and other (middle and upper) logs. The basal flare in butt logs can cause serious bias in the volume estimate unless allowance is made for it.

  • If a specified point of measurement on a log is unrepresentative, choose a representative point to replace it (except when using Bruce's formula - refer Table 2.4 (b)).

  • If measuring by diameter tape, choose a steel tape. Wind the tape firmly around the circumference of the log in a plane at right angles to the long axis and ensure that it is not twisted.

  

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January, 1999.