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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2.3.3 SURFACE AREA
The most active photosynthetic region in a tree crown comprises the young leaves at or near the crown surface. Thus, the surface area of the crown should be a useful predictor of the growth of a tree particularly prior to over-maturity. Surface area is estimated from crown width and depth assuming an appropriate solid shape for the crown space. Usually, this space is modelled as a conoid (particularly apt for conifers and young hardwoods) but for some species and under certain circumstances, a paraboloidal or hemispheric model may be more appropriate. Thus, the formulae appropriate for deriving the surface area of tree crowns, ignoring the crown base, are:
where CA is the crown surface area (m2), Db is the diameter at the base of the crown (m), and L is the crown depth (m).