Tree and Forest Measurement: Understanding Dendrometry
Dendrometry: Measuring Trees and Forests
Understanding Dendrometry
Dendrometry is the science that deals with determining the volume of forest trees and logs, as well as the growth and production of trees and forests. It involves measuring the volume of trees and forest stands, determining their age, and calculating their growth.
Key Concepts in Dendrometry
- Dendrometry: The measurement of trees and wooded masses.
- Epidometry: Studies growth in volume, determines the age of trees and forest masses, and spacing.
Types of Measurements
- Direct Measurement: This is made directly by the person performing the measurement on the tree.
- Indirect Measurement: This involves using optical instruments to take measurements.
- Estimate: This method saves time and reduces measurement costs in certain circumstances.
Diameter Measurements
Diameter measurement is a basic measure for calculating the volume of basal area growth.
- Instruments:
- Caliper: A ruler marked in centimeters and half centimeters, with a fixed or mobile arm at one end. For accurate readings, the arms should be perfectly parallel.
- Diameter Tape: A common metric tape.
Height Measurement
Height measurement is used especially for estimating volume and as an indicator of productive site capacity.
- Types of Height:
- Total Tree Height: The vertical distance between the tree base and apex.
- Commercial Height: The vertical distance from the stump to the point where the first bifurcation of the trunk begins, or where branches appear.
- Measurement Methods:
- Without Measuring Instruments: Using a rod.
- With Measuring Instruments: Using hypsometric scaling methods.
Measuring Standing Timber
The measurement of standing timber is calculated in two groups:
- Volume of a standing tree trunk.
- Basal Area: The cross-sectional area of the stem at breast height, 1.30 meters above ground.
- Morphic Coefficient: The relationship between the real volume (Vr) and the apparent volume (Vap) of a solid figure.
Volume Calculation of Felled Trees
Felled trees have defined geometric shapes, considering their heights:
- Base-stem: Forms a neloid.
- Portion of stem: Forms a cylinder.
- Truncated form: Forms an Apollonian paraboloid.
- Top: Forms a truncated cone.
Formulas for Volume Calculation
- Smalian’s Formula: Used to calculate the volume of logs.
- Huber’s Formula: Used to calculate the volume of a felled trunk.
Volume Calculation of Squared Timber
This involves calculating the timber volume of the work, including bark and sapwood. There are two methods:
- The Fourth Without Deduction: Applied to logs, styling them in their region of greatest diameter.
- The Fifth Deducted: Used to obtain a more perfect square, removing the bark and a good part of the sapwood.
Volume Calculation of Other Wood Products
- Crown: Estimated as an Apollonian paraboloid.
- Firewood: Measured by stacked volume (stereo).
- Bark: Measured for commercial and industrial purposes, often deducted from the total volume when sold debarked.