Lesson 5 spacer Growth Intercept Method
Lesson 1
Lesson 2
Lesson 3
Lesson 4
Lesson 5

Lesson Objectives

Growth Intercept Method Notes

How to Use the GI Method

Survey Timing

Number of Plots

1. Pre-stratifying the Opening

2. Select the Site Index Species

3. Collect Growth Intercept Data

4. Summary

Lesson 6
Lesson 7
Lesson 8
Lesson 9
Lesson 10
Lesson 11
Lesson 12
Appendix 1
Appendix 2
Appendix 3
Appendix 4
Appendix 5
Appendix 6
Appendix 7
Appendix 8
Appendix 9
Course Homepage

4. Summary

Once the strata boundaries have been finalized and the data have been collected, use the appropriate table to determine SI for each sample tree (Figure 5.8). The average SI for all of the sample trees site indices is then calculated.

If a sample tree has more than 30 rings at DBH, use the appropriate site index curves to determine its SI.

A complete set of tables is provided in Appendix 3 "Growth Intercept Method For Silviculture Surveys."

Step 1: Site index is determined for each sample tree in a stratum.

Step 2: Calculate the average site index for all sample trees per stratum.

Interior spruce growth intercept table

Figure 5.8. Summarizing GI survey data.


Here is data from three GI plots in stratum C of 82F045-001:

Species Rings Height SI
Hw 8 3.5 m ___
Hw 12 4.3 m ___
Hw 10 4.7 m ___

What is the SI predicted by each sample tree on this coastal site?


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