Stand Density Index

Stand Density Index first proposed by Reineke, 1933 translate the current stand density into the density of 10 inches trees.

$$sdi = tpa * \left( \frac{qmd}{10} \right)^{1.605}$$

where sdi is Stand Density Index, tpa is tree per acre, and qmd is quadratic mean diameter in inches.

$$sdi = tpha * \left( \frac{qmd}{25.4} \right)^{1.605}$$

where sdi is Stand Density Index, tpha is tree per hectare, and qmd is quadratic mean diameter in centimeters.

Example

Imperial Units
tpa = 200
qmd = 12.3
unittype = "imperial"
Answer = 278.8

Metric Units
tpa = 494.1
qmd = 31
unittype = "metric"
Answer = 680.2

Code

This code is stored in my Github.com/larsendr/ site. These are direct links to the raw code.

Excel® Visual Basic Code

R Statistical Package Code

Python Code

Go Code

Javascript for Node Code

C Code

Creative Commons License
Natural Resources Biometrics by David R. Larsen is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.

Author: Dr. David R. Larsen, Copyright 2012
Created: October 9, 2012
Last Updated: December 21, 2019