Fire risks in your forest

While fire can cause severe damage to your forest, it may not destroy it. 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, high temperatures and severe frosts.

While the forest and its fire environment are the hazard, people are the risk factor. In New Zealand 99% of wildfires are started by people’s activities – it only takes a spark.

A forest may not be destroyed if it suffers a fire. It’s possible to salvage damaged trees if you harvest them quickly.

Think of the fire risk before you plant

When you're planning your forest you should consider:

  • what species you're planting and how you're going to manage them
  • the local climate and terrain
  • vehicle access
  • access to water
  • fire history of the site
  • setback requirements when planting near powerlines.

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.

Drought and the increased risk of fire – Farm Forestry New Zealand

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 at least 4 metres wide which are not planted with trees.
  • Maintaining firebreaks by removing or managing vegetation. For example, mowing, grazing or blading it off with a light bulldozer.
  • Making sure equipment is in good order, with spark arresters if needed. This includes things like chainsaws and motorbikes.
  • 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:

  • thinning
  • harvesting
  • hot works
  • agricultural machinery work
  • public access.

Who can help?

Fire and Emergency staff can help landowners with risk assessments and fire reduction activities.

Preventing wildfires on forest plantations – Fire and Emergency New Zealand

Powerlines

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.

You must:

  • 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.

New Zealand Farm Forestry and Transpower have more information about safe setback and powerline risks.

Tree Grower: Forestry management around transmission lines – Farm Forestry New Zealand Trees and Transmission Lines – Transpower

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. The most hazardous period for forestry is within 12 to 18 months following pruning.

Read more about fire environmental factors and fire behaviour from Scion’s case study.

Fire behaviour case study: Mt Cook Station fire – Scion