Appendix 5 spacer Average Site Index Relationships Between Species
Lesson 1
Lesson 2
Lesson 3
Lesson 4
Lesson 5
Lesson 6
Lesson 7
Lesson 8
Lesson 9
Lesson 10
Lesson 11
Lesson 12
Appendix 1
Appendix 2
Appendix 3
Appendix 4
Appendix 5

When will this table be useful?

Why not assume all species on site have the same site index?

How to use this table


Appendix 6
Appendix 7
Appendix 8
Appendix 9
Course Homepage


This “site index species conversion table” provides the average site index expected for a species when site index is known for another species growing on the same site. The text that follows provides the background to assist in using the table properly.

When Will this Table Be Useful?

This table is useful when site index has been accurately determined for one species and it is required for another species. This could occur when the silviculture and inventory labels differ in leading species, and data were only collected on sample trees of one species. Rather than assume that both species have the same site index,use the conversion table to improve the estimate of the site index for the second species.

Why not assume all species on site have the same site index?

You should not assume that the site index determined for one species can be applied to all other species on the site. On any forest site, trees of one species will grow faster or slower than trees of a second species. A site may be good for one tree species, but only fair for a second species. Each species on the site has a unique site index.

How to Use the Table

To use the table, accurately determine the site index of one species. Find the section in the table that corresponds to this species and look up the site index predicted for a second species on the same site. For example, if site index was accurately determined as 22 m for Sx in an interior stand, find the section of the table labeled “Interior Sx site index.” Look across the section heading to find the column for site index 22 m. Look down this column to find that the average site index predicted for Fd on the same site is 21 m.


This table provides rough estimates of site index. These estimates are based on the average site index relationship between species. On any individual site, the site index for the second species may differ considerably from the average provided in the table. The most accurate site index for a second species on site is obtained by collecting growth intercept or site index curve data on suitable sample trees of the second species. However, on average, using the conversion table will provide you with better site index estimates than if you simply assume that all species on site have the same site index.


  PreviousTop of Pagenext