This Web guide provides background information for the second approximation of site index estimates for tree species according to site units of the Biogeoclimatic Ecosystem Classification system of British Columbia. The estimates themselves are presented in tabular form in two downloadable reports.

The background information consists of seven sections and two appendices. Following this introduction, Section 2 explains the basics of site index. In Section 3, the general relationships between site index and site factors are discussed. Section 4 provides a summary of the methods used to generate the site index estimates presented in the two reports. Section 5 outlines the content and format of the report tables. Section 6 explains how to use the tabular information presented in each report to estimate site index in the field. References to literature cited in this guide are provided in Section 7. Appendix 1 contains a site index species conversion table for mixed species stands. Appendix 2 provides a listing of additional references, resources, and important contacts.

Two reports are available in PDF format and as downloadable Microsoft Excel files. The first report, "Site Index-Site Unit Report by Region", provides a compilation of site index estimates by biogeoclimatic unit for each forest region. The second report, "Site Index-Site Unit Report by Biogeoclimatic Unit", displays site index estimates by site series for each biogeoclimatic subzone/variant.

The site index estimates provided in these reports are second approximations as they report mean plot site index and its standard error for each BEC site series/species combination that have a minimum sample size of 7. This new estimate replaces the first approximation (1997) site index class estimate only if the minimum sample size criterion is met. As more data become available, subsequent approximations will be produced and named by year, e.g., 2006 approximation.

A companion report, "SIBEC comparison report", provides an at-a-glance view of the changes in the latest release of the SIBEC estimates to the 1997 Approximation.

Site index estimates for some hardwood species are also included in this edition. To contribute data to the provincial SIBEC (Site Index-Biogeoclimatic Ecosystem Classification) data warehouse, please contact the SIBEC Administrator , B.C. Ministry of Forests.

For SIBEC data collection standards, see the Site Productivity Working Group’s SIBEC Sampling and Data Standards (Version 5.3).

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