In British Columbia, grizzly bears are considered to be a "vulnerable" species, and, in some parts of the province, grizzly bear populations are considered to be "threatened" (B.C. Ministry of Environment, Lands and Parks 1997). Rich valley bottoms in the Coastal Western Hemlock Zone are important grizzly bear habitat (MacHutchon et al. 1993). These areas are also valued for high timber productivity.
Grizzly bear food plants grow in abundance under the partially open canopy of primary forests in valley bottom sites (MacHutchon et al. 1993). In contrast, stands managed primarily for timber supply have little, if any, understory of value to grizzly bears (Alaback and Herman 1988). Silvicultural systems and treatments that supply food for bears throughout the stand rotation will help provide habitat while maintaining timber production.
The provincial government, through the Grizzly Bear Conservation Strategy (B.C. Ministry of Environment, Lands and Parks 1995) and the Identified Wildlife Management Strategy (B.C. Ministry of Environment, Lands and Parks 1999), is taking steps to conserve and manage grizzly bear habitat in critical areas.
Trials comparing silviculture treatments and stocking regimes that attempt to maintain or enhance grizzly bear forage supply in the Coastal Western Hemlock (CWH) biogeoclimatic zone began in 1992 (Johnson 1995). The goal of these projects has been to establish and maintain a commercially viable stand of trees, while managing for conditions conducive to the survival, growth, and productivity of grizzly bear forage throughout the rotation of the stand (Johnson and McLennan 2000).
Guidelines for integrating grizzly bear habitat and silviculture have been developed based on these trials. These guidelines are described in detail in both the Vancouver Forest Region and Prince Rupert Forest Region Establishment to Free Growing Guidebook (Appendix 11). The guidelines:
- identify the high-priority forested ecosystems associated with grizzly bear forage production (see Table 1);
- describe the recommended stocking standards for those ecosystems;
- suggest alternative silviculture treatments;
- list the main plant species considered to be preferred grizzly bear forage; and
- suggest parameters for conducting and monitoring field operations.
Where conditions are suitable, forest managers are encouraged to follow the guidelines when developing prescriptions. An adaptive management approach (see sidebar) to guideline application is recommended. This approach will produce the critical feedback needed to improve our understanding of grizzly bear habitat management through silviculture and, in turn, to refine the guidelines.
These adaptive management projects should include a mix of operational practices. Short- and long-term costs, forage responses, crop tree survival, and growth and yield responses should be monitored over time.
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Updated April 19, 2007