For average tree diameters between 7 to 15 inches, which chart should be used?

For average tree diameters between 7 to 15 inches, which chart should be used?

• A. The chart on the left
• B. The chart on the right
• C. The chart in the middle
• D. No chart is used

Answer: (B)

Matching the diameter class to the chart is essential. Charts are calibrated for specific DBH ranges, so you get reliable estimates only when the trees fall within that range. For average diameters in the mid-range, 7 to 15 inches, the chart on the right is tuned for that band, providing accurate interpolation and reflecting how the relationship between diameter and the target metric behaves in mid-sized trees. Using a chart meant for smaller diameters would force extrapolation beyond its validated range, reducing accuracy, while a chart for larger diameters would misrepresent the values within this range. Not using a chart at all misses a standardized, consistent method.

Matching the diameter class to the chart is essential. Charts are calibrated for specific DBH ranges, so you get reliable estimates only when the trees fall within that range. For average diameters in the mid-range, 7 to 15 inches, the chart on the right is tuned for that band, providing accurate interpolation and reflecting how the relationship between diameter and the target metric behaves in mid-sized trees. Using a chart meant for smaller diameters would force extrapolation beyond its validated range, reducing accuracy, while a chart for larger diameters would misrepresent the values within this range. Not using a chart at all misses a standardized, consistent method.