Module 3 — Stand level components
of biodiversity
British Columbia
Ministry of Forests
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Module 3, Part B — Wildlife trees — continued
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Module 3
Worker safety considerations for wildlife trees

icon Are there other worker safety considerations?
If so, name them.


Some wildlife trees present a hazard to workers and some do not. In general, the risk that a tree is dangerous is related to its decay class and factors such as tree defects, lean, wild exposure or slope and the type of work activity to be carried out. 

The following information about safety considerations is based on the nine classifications of wildlife trees (figure 8).

Class 1

class 1 live healthy tree
Class 1

These trees are healthy with minor or no defects and as such pose no safety hazard.

Class 2

class 2 live unhealthy tree
Class 2

These trees range from being live, realtively healthy trees to those that have deformities or defects. They may have insect damage, old wounds, lightning strikes, or fire damage.

These trees can be stable and pose the least threat to workers, except when they suffer butt rot or other disease or infestation.

Sometimes their tops pose a hazard. A Class 2 tree with an old wound may be unstable because of associated internal decay.

Resinous conifers (red cedar and yellow cedar) last longer; nonresinous trees are more hazardous.

Classes 3, 4, & 5

class 3 dead tree
Class 3  

class 4 dead tree
Class 4  
class 5 dead tree
Class 5

These trees are variable in degree of hazard. Depending on the location, lean, damage, decay and work activity (level of disturbance), they may be hazardous or not hazardous

Classes 6 & 7

class 6 dead tree
Class 6    
class 7 dead tree
Class 7   

These trees are often unstable and commonly pose a hazard to workers. However, certain species (such as red cedar and yellow cedar, Douglas-fir, ponderosa pine, and larch) have spreading and large buttress roots, and are often stable even within these classes.

Classes 8 & 9

Class 8 
Class 9

These trees are often, but not always, too short to present a hazard.


Only people who have successfully completed a 2-day course are certified to carry out wildlife/danger tree assessments.

See also Figure 8: British Columbia's wildlife tree classification system 

See the Wildlife/Danger Tree Assessor's Course (Wildlife tree classification system for BC) for detailed information on these classes.

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