Fire risks in your forest
While fire can cause severe damage to your forest. There are things you can do to minimise risk and damage.
What is the risk of fire?
Fire is a minor risk in many areas of New Zealand. Dry, eastern and central areas of the country are most at risk. These areas are more prone to drought, strong winds, high temperatures and severe frosts.
While the forest and its fire environment are the hazard, people are the risk factor. In New Zealand 98% of wildfires are started by people’s activities – it only takes a spark.
A fast-moving rural fire not only destroys forests, it can also extend to pasture, crops and vegetation, homes and livelihoods.
Think of the fire risk before you plant
When you're planning your forest you should consider:
- the local climate and terrain
- vehicle access
- access to water
- fire history of the site
- setback requirements when planting near powerlines and boundaries
- council and legislation requirements
- what species you're planting and how you're going to manage them.
There is a range of burn rates for tree species in New Zealand.
Climate change predictions
It's expected there will be a 60-70% increase in wildfire risk by 2040 due to hotter, drier, longer summer seasons. We’ve seen fires start earlier in the year (August and September) with dry conditions lasting till May. Many areas of New Zealand experienced drought during the 2019 and 2020 summers.
With the predicted El Niño conditions, many areas of New Zealand may experience drought during the 2023 and 2024 summers.
Reduce the fire risk in your forest
You can reduce the risk of fire by:
- Establishing firebreaks to stop a fire getting into the forest or to slow its progress. Firebreaks are strips of land that provide a gap in vegetation to slow or stop the progress of fire.
- Maintaining firebreaks by removing or managing vegetation. For example, mowing, grazing or blading it off with a light bulldozer.
- Making sure machinery and equipment is in good order, with suitable fire extinguishers on board and spark arresters if needed. This includes things like chainsaws and motorbikes.
- Consider how and where you use battery power tools, equipment and vehicles.
- Developing a fire risk management plan for your forest that includes actions such as:
- managing activities in the forest
- limiting access during high fire risk periods
- coordinating fire control with neighbours and other local forest owners.
Forest grazing is a way of controlling undergrowth around the edges or in lower stocked plantations. This helps reduce fuel availability (grass) and fire hazards.
When fire risk is extreme, you should suspend activities such as:
- hot works for example use of welders or grinders
- agricultural machinery work
- public access.
Who can help?
Fire and Emergency staff can help landowners with risk assessments and fire reduction activities.
Wildfires associated with powerlines are often started and continued when auto-reclosers restore power to lines that may have been brought down in high winds.
- plant within safe setback areas
- make sure there is no branch intrusion in powerline corridors
- notify powerline companies of any powerline or isolator faults, and encroaching vegetation growth.
The Electricity (Hazards from Trees) Regulations 2003 are currently being updated by the Ministry of Business, Innovation and Employment.
New Zealand Farm Forestry and Forest Industry Safety Council (SafeTree) have more information about safe setback and powerline risks.
Forest management research
There are many different forest management regimes. Research shows the amount, dryness and arrangement of the fuel has a significant impact on the fire hazard.
How you look after your forest and when you complete forest management work can increase or reduce fire risk. For example, if you thin trees in summer, you increase the risk. The most hazardous period for forestry is within 12 to 18 months following pruning.
Read more about fire environment factors and fire behaviour from Scion’s case study.