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Fall-down Rates of Subalpine Fir Snags at Sicamous Creek: Implications for Worker Safety and Habitat Supply

Author(s) or contact(s): D.J. Huggard
Source: Research Branch
Subject: Safety
Series: Extension Note
Other details:  Published 1997. Hardcopy is available.


Current regulations require that all dead trees over 3 m tall are felled when an area is being logged (Workers' Compensation Board regulation 60.38). This clearly protects workers because tree-falling, especially hand-falling, is more dangerous when other trees, live or dead, could interfere with the falling tree. Snags must also be removed within 1.5 tree heights of work areas. This buffer is intended to decrease the risk that a worker in a block will be injured by a falling dead tree. However, there are several costs to snag-falling:
- Ecological damage. Many wildlife species require snags, including 35% of bird species and 30% of mammal species in British Columbia (Bunnell and Kremsater 1990). Different species require different stages of decay, from recently dead snags to soft stubs, and many species require canopy-sized snags. Many other, lesser-known species are linked to snags, including lichens (Goward and Arsenault 1997), fungi, and invertebrates in Sweden, 268 species of invertebrates are threatened or endangered due to loss of snags in managed forests (Berg et al. 1994).
- Worker hazard. Snag-falling is one of the most dangerous occupations in forestry. It is particularly dangerous in the 1.5 tree-height buffer Economic costs. Because their job is so dangerous, snag-fallers are well-paid, and the work cannot be done quickly. As a result, snag-falling costs are high ($670/ha in 1995 at the Sicamous Creek site). Also, snag-falling buffers around cutblocks can be large areas - a 10-ha cutblock, 400 x 250 m, requires snag-falling in 6.5 adjacent hectares if trees are 30 m tall.

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Updated April 17, 2007