Danger Tree Awareness

Question 1

What is a Dangerous Tree?

Answer 1

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)

Question 2

What considerations do you need to think about when working in forestry areas?

Answer 2

• 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

Question 3

What things do you need to remember when working with Danger Trees?

Answer 3

• 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

Question 4

What are some reasons that Dangerous Trees may be left on site unintentionally?

Answer 4

• 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

Question 5

What are some reasons that Dangerous Trees may be left on site intentionally?

Answer 5

• 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

Question 6

What are Wildlife Trees?

Answer 6

Trees left on a worksite to provide habitat for wildlife - eg. birds and animals

Question 7

Why might wildlife trees present a hazard to workers and what risk management steps need to be taken when working around them?

Answer 7

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.

Question 8

What steps do you need to take when working in forestry in regards to Danger Trees?

Answer 8

1. Before you start work, you need to communicate with your co-workers about the hazards involved in your shared activities
2. Discuss the mitigations you will use to reduce the risk of worker injury
3. 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

Question 9

What is an Emergency Evacuation Plan?

Answer 9

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.

Question 10

When working around Danger Trees, what 2 factors can increase the likelihood of a bad outcome?

Answer 10

1. EXPOSURE - how long and under what condition you would be available as a ‘target’ for the hazard to hit.
2. MECHANISM - how the hazard is set in motion i.e. wind, fire in the tree, snowload, or vibration from a saw or heavy equipment

Question 11

What 2 choices do you have when confronted by a Danger Tree?

Answer 11

1. 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.
2. 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.

Question 12

What steps do you need to keep yourself and others safe when working in forestry?

Answer 12

1. Have a valid Emergency Evacuation Plan
2. Recognise the hazards
3. Mitigate the hazards
4. If it’s too dangerous to mitigate the hazards, change your plans
5. Recognise there may be a new set of risk when you do so

Question 13

What are some factors that can increase the risk of a Danger Tree becoming dangerous to workers?

Answer 13

• 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

Question 14

What must happen when a worker is working around a Danger Tree?

Answer 14

1. When people could get hurt by a tree, it must be removed or assessed
2. A Wildlife Dangerous Tree Assessor (DTA) who is trained and certified must complete the assessment
3. The ‘heavier’ the work, the more comprehensive the assessment needs to be
4. Falls will mark dangerous trees for removal

Question 15

How are Danger Trees marked?

Answer 15

• 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

Question 16

What is a No Work Zone?

Answer 16

• If a tree or trees can’t be removed, a No-Work-Zone (NWZ) is set up to keep workers out of an area
• NWZ can also be used to mark a small hazard or prevent damage that might happen if the tree is felled
• Must be sufficiently marked so workers see it clearly
• Should be 1.5 times the length of the hazardous defect - larger under other conditions, like a steep slope
• Never enter a NWZ

Question 17

What must be communicated to workers about areas that have been assessed?

Answer 17

Workers must be clearly informed about:
a) what areas have been assessed,
b) to what level they have been assessed,
c) how safe trees and NWZs are marked,
d) and any issues that may have arisen from the assessment

Question 18

How can risk assessment information be communicated to workers?

Answer 18

1. Morning briefings
2. Maps or site handouts
3. Safety boards
4. Notes on ribbons at the start and end of sections
5. Other ways as appropriate

Question 19

What must be included in briefings before beginning work on a site?

Answer 19

The potential presence of Danger Trees and if the site has been assessed.

Question 20

How can changing conditions affect the risk of working in an area of forestry?

Answer 20

Unexpected weather events like strong winds, heavy rain, or snow can create new danger trees even after previous assessment. It could disrupt the use of certain types of equipment. Consequently, you must be aware of the hazards that changing weather conditions may create. Reassess what you’re doing to make sure the area is still safe to work in and how you could mitigate the hazards

Question 21

What specific hazards or combinations of hazards does a Danger Tree possess?

Answer 21

• Dead forked top with crack at the union
• Lightning scar
• Nest cavity
• Witches’ broom (with visible structural weakness)
• Large dead limb (with visible structural weakness)
• Broken or hanging limb
• Stem scar (damage with visible signs of decay)
• Butt canker
• Split trunk (from frost cracks, tension splits)
• Fungal fruiting bodies (conks)
• Basal fire scar
• Mushrooms indicating root rot
• Cut or burned root
• Leaning tree
• Rotten roots

Question 22

What are the simplified characteristics of a Danger Tree?

Answer 22

1. Deterioration or rot
2. Overhead conditions
3. Physical damage
4. Lean
5. Location

Question 23

What might the mushrooms growing on trees tell you?

Answer 23

These are a composting fungus that may tell you that the inside of a tree is rotten.

Question 24

What are the 4 steps to managing a Danger Tree in your workplace

Answer 24

1. Site assessment and confirming what activities you’ll be doing on site
2. Look for suspect Danger Trees
3. Make a decision as to whether a tree is safe or dangerous
4. Document and communicate to your crew that the hazards have been controlled or that you’ve communicated what needs to be done to make the site safe

Question 25

What is the most important advice for working in forestry?

Answer 25

Never assume an area is completely safe.
When in doubt, back out (and tell your supervisor)

Question 26

What is the protocol for entering a worksite?

Answer 26

1. Look at your surroundings
2. Scan the work area and note anything that seems off
3. Communicate hazards to other workers
4. Report hazards to your supervisor

Question 27

What things should you pay attention when you enter a worksite?

Answer 27

1. General condition of forest stand
2. Signs of danger tree work
3. Overhead hazards - leaning or broken trees
4. Retention patches and block boundaries
5. Different forest types - coniferous versus deciduous

Question 28

What things should you pay attention to while you are working that may increase risk of bad outcomes?

Answer 28

1. Changing weather
   - Changes in wind direction and wind speed
   - Advancing storms
   - Other weather conditions that can increase hazards in the worksite
2. Changing work
   - ‘Heavier’ work i.e. working with heavier machinery/equipment that could disturb danger trees
   - Moving into a new area