(2020) BC's Old Growth: A Last Stand for Biodiversity

By Karen Price, Rachel Holt, and Dave Daust

The Province has appointed a task force to investigate the state of BC’s old growth forest. The panel will report to government in April 2020.

The old growth task force website1 shows a map of the old growth forest in BC — and says “Based on government’s working definition, old-growth forests comprise about 23% of forested areas, or about 13.2 million hectares”.

We have written this report because old growth cannot be portrayed by a single number or map. Old forest comes in many forms.

We have used publicly available provincial data and definitions to examine the status of different types of old forest found across the province in different ecosystems (biogeoclimatic variants) and productivity classes. These distinctions matter because while all forms of old growth have inherent value, different types provide tremendously different habitat, functional, cultural, spiritual and timber values. BC’s globally rare high productivity forests have particular value for their high biomass, structural complexity and stable carbon storage.

Our analysis concludes the following:

The provincial total area of old forest (~13.2 million hectares) matches our total.
The vast majority of this forest (80%) consists of small trees:
- › ~5.3 million hectares have site index2 5–10m; another ~5.3 million hectares have a site index 10–15m.
- › Small trees characterize many of BC’s natural old forest types, including black spruce bog forests in the northeast, subalpine forests at high elevation, and low productivity western redcedar forests on the outer coast.
- › Large areas of this old forest type remain because the trees are too small to be worth harvesting (under today’s prices).
In contrast, only a tiny proportion of BC’s remaining old forest (3%) supports large trees:

› ~380,000 hectares have a site index 20–25m, and only ~35,000 hectares of old forest have a site index greater than 25m.

› These types of forests match most people’s vision of old growth. They provide unique habitats, structures, and spiritual values associated with large trees.

› Productive old forests are naturally rare in BC. Sites with the potential to grow very large trees cover less than 3% of the province. Old forests on these sites have dwindled considerably due to intense harvest so that only 2.7% of this 3% is currently old (see pie chart). These ecosystems are effectively the white rhino of old growth forests. They are almost extinguished and will not recover from logging.

› Over 85% of productive forest sites have less than 30% of the amount of old expected naturally, and nearly half of these ecosystems have less than 1% of the old forest expected naturally. This current status puts biodiversity, ecological integrity and resilience at high risk today.

A Last Stand For Biodiversity (2020).pdf