Ministry of Forests SIBEC Web Site


•	1. Introduction
•	2. Site Index Basics
•	3. Site Index and Site Factors
•	4. Methodology
•	5. Report Format and Content
•	6. Field Use
•	7. References
•	Appendix 1. Species Conversion Tables
•	Appendix 2. Resources

2008 Approximation

•	SISU By Region Report (PDF Format)
•	SISU By Region Report (Excel Format)
•	SISU By BGC Unit Report (PDF Format)
•	SISU By BGC Unit Report (Excel Format)
•	Custom Reports Web Page
•	Comparison Report


•	Sampling and Data Standards Version 5.2


•	SIBEC e-brochure
•	SIBEC Technical Report

Site Index estimates by Site Series (SIBEC) - second approximation

APPENDIX 1 - Site Index Species Conversions For Mixed Species Stands

The site index species conversion tables below provide 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 tables properly.

When Will These Tables Be Useful?

These tables are useful when site index is in a SISU table for one species and it is required for another species but the site index cannot be obtained using other methods, including SIBEC. 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 Tables

To use the conversion tables, determine the site index of one species from the SISU tables. Find the conversion table that corresponds to this species and look up the site index predicted for a second species on the same site. For example, if the SISU-based site index was 22 m for Sx in an Interior stand, find the table labelled "When You Know 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.

Notes

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 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.

Also see Research Branch's SiteTools website for electronic site index species conversion tables.

Average Site Index Relationships for Interior Species

When you know interior Bl site index (1)

The species that can be predicted

Average site index (m) relationship

Interior Pl

Interior Sw

10	12	14	16	18	20	22	24	26	28	30
10.4	12.6	14.7	16.9	19.1	21.3	23.5	25.6	27.8	30.0	32.2
9.7	12.0	14.3	16.7	19.0	21.3	23.6	26.0	28.3	30.6	32.9

Example: If you have data that were gathered on interior Bl that indicates a site index of 22, it can be used to predict that the site index of interior white spruce will be 23.6.

When You Know Interior Fd Site Index

	10	12	14	16	18	20	22	24	26	28	30
Interior Pl	9.9	12.1	14.2	16.4	18.5	20.6	22.8	24.9	27.1	29.2	31.3
Interior Sw	7.1	9.8	12.6	15.3	18.0	20.7	23.4	26.1	28.8	31.5	34.3
Interior Hw	6.1	8.4	10.6	12.9	15.2	17.4	19.7	21.9	24.2	26.4	28.7
Interior Lw	10.9	12.9	14.9	17.0	19.0	21.0	23.1	25.1	27.2	29.2	31.2

When You Know Interior Hw Site Index

	10	12	14	16	18	20	22	24	26	28	30
Interior Fd	13.4	15.2	17.0	18.8	20.5	22.3	24.1	25.8	27.6	29.4	31.2

When You Know Interior Lw Site Index

	10	12	14	16	18	20	22	24	26	28	30
Interior Pl	8.4	10.5	12.6	14.6	16.7	18.8	20.9	23.0	25.0	27.1	29.2
Interior Fd	9.1	11.1	13.1	15.0	17.0	19.0	20.9	22.9	24.9	26.8	28.8

When You Know Interior Pl Site Index

	10	12	14	16	18	20	22	24	26	28	30
Interior Bl	9.6	11.5	13.3	15.2	17.0	18.8	20.7	22.5	24.3	26.2	28.0
Interior Fd	10.1	11.9	13.8	15.7	17.5	19.4	21.3	23.1	25.0	26.9	28.7
Interior Lw	11.5	13.5	15.4	17.3	19.2	21.2	23.1	25.0	26.9	28.8	30.8
Interior Sb	9.2	10.4	11.7	13.0	14.3	15.5	16.8	18.1	19.4	20.6	21.9
Interior Sx	8.7	10.9	13.1	15.2	17.4	19.6	21.8	23.9	26.1	28.3	30.5

When You Know Interior Sb Site Index

	10	12	14	16	18	20	22	24	26	28	30
Interior Pl	11.3	14.5	17.6	20.7	23.9	27.0	30.1	33.3	36.4	39.5	42.7

When You Know Interior Sx Site Index

	10	12	14	16	18	20	22	24	26	28	30
Interior Bl	10.3	12.0	13.7	15.4	17.2	18.9	20.6	22.3	24.0	25.8	27.5
Interior Fd	12.1	13.6	15.1	16.5	18.0	19.5	21.0	22.4	23.9	25.4	26.9
Interior Pl	11.2	13.0	14.9	16.7	18.5	20.4	22.2	24.1	25.9	27.7	29.6

Average Site Index Relationships for Coastal Species

When You Know Coastal Ba Site Index

	15	18	21	24	27	30	33	36	39	42
Coastal Hw	17.2	20.3	23.3	26.3	29.4	32.4	35.5	38.5	41.6	44.6

When You Know Coastal Cw Site Index

	15	18	21	24	27	30	33	36	39	42
Coastal Hw	17.0	20.1	23.3	26.4	29.6	32.7	35.8	39.0	42.1	45.3

When You Know Coastal Fd Site Index

	15	18	21	24	27	30	33	36	39	42
Coastal Hw	13.1	15.7	18.4	21.1	23.8	26.5	29.2	31.9	34.6	37.3

When You Know Coastal Hw Site Index

	15	18	21	24	27	30	33	36	39	42
Coastal Fd	17.2	20.5	23.8	27.2	30.5	33.9	37.2	40.5	43.9	47.2
Coastal Ss	13.8	17.5	21.3	25.0	28.8	32.5	36.3	40.0	43.7	47.5
Coastal Cw	13.1	16.0	18.8	21.7	24.6	27.4	30.3	33.2	36.0	38.9
Coastal Ba	12.8	15.8	18.7	21.7	24.6	27.6	30.6	33.5	36.5	39.4

When You Know Coastal Ss Site Index

	15	18	21	24	27	30	33	36	39	42
Coastal Hw	16.0	18.4	20.8	23.2	25.6	28.0	30.4	32.8	35.2	37.6