New Provincial Format for the BEC Method
In the fall of 1997, the B.C. Ministry of Forests released the document Site
index estimates by site series for coniferous tree species in British
Columbia. This book is known as the SIBEC guide (Site IndexBiogeoclimatic
Ecosystem Classification). The SIBEC guide provides BEC method estimates
of SI for many of the common species-site series combinations in the
province. The SIBEC guide replaces the BEC method SI estimates in the
Vancouver, Prince Rupert, and Nelson eco-guides.
In addition to tables of average SI by species, site series, and forest region, the SIBEC guide includes a discussion of:
- the relationships between SI and soil moisture, soil nutrients, and biogeoclimatic subzone;
- the accuracy that can be expected from the BEC method and its limitations; and
- the overall SIBEC program.
Figures 4.5 to 4.7 provide examples of the SIBEC guide tables. When these tables are compared to the previous examples of the old BEC method formats from the Nelson, Vancouver, and Prince Rupert forest regions, it is clear that the new SIBEC guide:
- provides site index estimates for more speciessite series
- indicates the reliability of the SI estimates;
- includes footnotes by the regional ecologists to supplement the
- provides greater resolution and clarity than the Prince Rupert and
Vancouver forest region formats; and
- provides site index as a class midpoint with 4 m classes in the
CDF, CWH, and MH zones and 3 m classes in all other zones.
Figure 4.5. New province-wide format for BEC method
Vancouver Forest RegionCWHdm (click on the above thumbnail to
see a full screen version of the table).
Figure 4.6. New province-wide format for BEC methodPrince
Rupert Forest RegionCWHwm (click on the above thumbnail to see
a full screen version of the table).
Figure 4.7. New province-wide format for BEC methodNelson
Forest RegionMSdk (click on the above thumbnail to see a full
screen version of the table).