Where a given tree species is
present within the site series, a site index point estimate is given along with its
associated standard error and the number of sample plots on which the site index data are
based. For some site series, the estimates did not have sufficient samples and these
estimates are reported as site index class mid-points (see Table 2).
Therefore, the estimates provided in the reports are a mix of:
- second approximation mean site index estimates (or point estimates), and
- first approximation site index class estimates.
See Section 4 for more information about these
two types of estimates.
Table 2
Coast (1) |
Interior (2) |
Site index |
Site class |
0.0-5.9 |
4 |
6.0-9.9 |
8 |
10.0-13.9 |
12 |
14.0-17.9 |
16 |
18.0-21.9 |
20 |
22.0-25.9 |
24 |
26.0-29.9 |
28 |
30.0-33.9 |
32 |
34.0-37.9 |
36 |
38.0-41.9 |
40 |
42.0-45.9 |
44 |
46.0-49.9 |
48 |
50.0-53.9 |
52 |
|
Site index |
Site class |
0.0-4.4 |
3 |
4.5-7.4 |
6 |
7.5-10.4 |
9 |
10.5-13.4 |
12 |
13.5-16.4 |
15 |
16.5-19.4 |
18 |
19.5-22.4 |
21 |
22.5-25.4 |
24 |
25.5-28.4 |
27 |
28.5-31.4 |
30 |
31.5-34.4 |
33 |
34.5-37.4 |
36 |
37.5-40.4 |
39 |
|
- CWH, CDF, and MH zones
- All other zones
In general, site index class estimates use 3-m classes, with the exception being the
Coastal Western Hemlock (CWH), Coastal Douglas-fir (CDF), and Mountain Hemlock (MH) zones,
where 4-m classes are used. Classes were used for first approximation estimates to dampen
some of the inherent variability in the raw data, make it easier for experts to verify and
adjust the regression estimates if required, and to suggest to users an approximate level
of precision.
5.2 Format of the
Two Site Index-Site Unit Reports
In the
Site Index-Site Unit Report
by Region, the tables for biogeoclimatic
subzones and variants (BGC units) are indexed alphabetically by forest region and BGC
units. There is one table for each forested BGC unit in the region.
Each regional BGC unit table contains a data column for each coniferous tree species
occurring in the unit and a row for each of the reported site series. Point estimates of
mean plot site index are accompanied by the associated sample size and the standard error.
Site index class estimates are also included in this report (see Figure
5). Most non-forested site series (wetlands and grasslands) are excluded.
Figure 5. The tabular format of the Site Index-Site Unit
Report by Region.
In the Site Index-Site Unit Report by Biogeoclimatic Unit, the tables are indexed
alphabetically by biogeoclimatic subzones and variants (BGC units) and numerically by site
series associations.
The Report by Biogeoclimatic Unit contains both point estimates of mean plot site index
and site index class estimates. The site series data summary provided includes tree
species abbreviations, sample size, mean site index, and associated standard error (see Figure 6).
Figure 6. The tabular format of the Site Index-Site Unit
Report by Biogeoclimatic Unit.