Danger Tree Awareness Flashcards
What is a Dangerous Tree?
A Dangerous Tree means a tree that is a hazard due to
a) its location or lean,
b) its physical damage,
c) overhead conditions
d) deterioration of its limbs, stem or root system
e) any combination of the conditions in paragraphs (a) to (d)
What considerations do you need to think about when working in forestry areas?
- Trees are not uniform
- Trees are in various states of life and strength
- Trees may have visible and invisible defects
- When some trees are disturbed (even lightly) they can cause injury
- This is when a tree becomes a Danger Tree
What things do you need to remember when working with Danger Trees?
- Any tree can be dangerous and must be checked to see if workers can work around it
- Trees with a visible hazard must be checked by a qualified person
- Generally danger trees are cut down so that workers can have a safe worksite
What are some reasons that Dangerous Trees may be left on site unintentionally?
- Human error (missed during assessment)
- Hidden defects
- Unexpected changes due to weather after previous assessment (leaving new danger trees behind)
- In an area that hasn’t been checked
What are some reasons that Dangerous Trees may be left on site intentionally?
- Too dangerous to remove the hazard (eg. if tree is on steep slope, too many danger trees to fall safely, or nobody qualified to cut down)
- Good wildlife habitat characteristics (may house wildlife)
- Ecologically or culturally valuable
- Stand level biodiversity
- Left as seed trees
- Act as visual screens for nearby areas
What are Wildlife Trees?
Trees left on a worksite to provide habitat for wildlife - eg. birds and animals
Why might wildlife trees present a hazard to workers and what risk management steps need to be taken when working around them?
Wildlife Trees may present a hazard because although characteristics such as hollows may be beneficial for the wildlife that lives in them, it may become a risk due to the structural instability that can cause.
These are a type of Danger Tree and workers must know where wildlife trees are located on the worksite so that they can lower the risk of a bad outcome.
What steps do you need to take when working in forestry in regards to Danger Trees?
- Before you start work, you need to communicate with your co-workers about the hazards involved in your shared activities
- Discuss the mitigations you will use to reduce the risk of worker injury
- Knowing that you will be exposed to hazards in your work environment means that you will need an emergency work evacuation plan in place for all field activities
What is an Emergency Evacuation Plan?
It is a pre-planned protocol for an emergency response in the event of an injury. The plan should be customised to fit the project being worked on.
When working around Danger Trees, what 2 factors can increase the likelihood of a bad outcome?
- EXPOSURE - how long and under what condition you would be available as a ‘target’ for the hazard to hit.
- MECHANISM - how the hazard is set in motion i.e. wind, fire in the tree, snowload, or vibration from a saw or heavy equipment
What 2 choices do you have when confronted by a Danger Tree?
- Mitigate the hazard i.e. you can fell the tree or let it burn down. You can use use mechanical means or explosives to bring the tree down.
- If you’re unable to safely mitigate the hazard, Change your plans. This means you need to find a safer way to accomplish your objectives i.e. You can re-locate your fireline, find a safer parking area, wait until the wind stops, or avoid the area altogether. Walking away is a valid mitigation when you feel that the risk of a bad outcome is too high.
What steps do you need to keep yourself and others safe when working in forestry?
- Have a valid Emergency Evacuation Plan
- Recognise the hazards
- Mitigate the hazards
- If it’s too dangerous to mitigate the hazards, change your plans
- Recognise there may be a new set of risk when you do so
What are some factors that can increase the risk of a Danger Tree becoming dangerous to workers?
- High winds - mature, solid trees can be uprooted by extreme winds and trees with defects can be blown over by lower speed winds
- Rotten or fire-damaged roots and stems
- Wildfire
What must happen when a worker is working around a Danger Tree?
- When people could get hurt by a tree, it must be removed or assessed
- A Wildlife Dangerous Tree Assessor (DTA) who is trained and certified must complete the assessment
- The ‘heavier’ the work, the more comprehensive the assessment needs to be
- Falls will mark dangerous trees for removal
How are Danger Trees marked?
- Colour flagging or paint may be used to mark a dangerous tree
- “D” or “X or coloured dots may be used as markings
- “No Work Zone” flagging indicates the presence of standing dangerous trees; do not enter these areas
- Communication about the meaning of a marking system is essential
