Wildfire research focuses on beech forests

New research is putting the litter bed flammability of New Zealand’s beech forests under the microscope. The Bioeconomy Science Institute Maiangi Taiao’s extreme wildfire research team and Lincoln University academic staff are jointly supervising student Georgia Stevenson, who is conducting ignition experiments in Canterbury beech forests between now and April as part of her PhD.

These experiments – the first to examine litter flammability and conduct field-based ignition tests in any native forest type in NZ – are taking place at two locations near Craigieburn. The tests are small in scale, with flames only allowed to spread for 30cm before being extinguished.

Through these experiments, Georgia will evaluate the thresholds at which beech forests can ignite and spread. Her main aim is to identify the conditions under which litter beds will ignite and develop into self-sustained wildfires in mountain or black beech forests in the region.

“It’s essential to understand litter flammability for effective fire management,” Georgia says. “Results from this research aim to help the prediction and management of wildfires in these forests.”

The timing of the experiments is weather-dependent but they will run on up to 15 days throughout the planned timeframe. Georgia has Department of Conservation authorisation to do the research. Seven attempts at ignition have been made so far, over two burn days. “Most of these haven’t succeeded,” Georgia says. “The litter has been too damp, and we’re hoping for drier and warmer conditions so we can conduct tests until we get a self-sustaining ignition.

Bioeconomy Science Institute fire ecologist Shana Gross says wildfires in these forests present a significant challenge for conservation and the management of landscape fire risk. “Several significant wildfires have impacted native beech rainforests in NZ over the past decade.

“New Zealand forests are not considered very flammable because they’re often too wet to burn. However, everything can burn when conditions align, as we saw in the 2024 Bridge Hill fire that burned a significant amount of beech forest in the Craigieburn area. Georgia’s research is helping identify the conditions under which a native forest no longer acts as a fire break – and where we would lose these important ecosystems.

“In NZ, the fuel moisture conditions we use as part of the fire weather warning system were developed for pine forests,” Shana says. “Georgia’s research is an important step in helping us understand how these fuel moisture conditions relate to the fire hazard in NZ’s beech forests.”

Georgia’s experiments are part of and funded by a larger Ministry of Business, Innovation and Employment project aimed at better understanding when native forests will ignite and when fires will escalate into extreme wildfires. The Brian Mason Scientific and Technical Trust has also contributed funding to Georgia’s project.

Strict safety protocols will be in place for all experiments. These include keeping the ignition tests at a small scale and always having a team of firefighters and their equipment on hand.

Source & image credit: NZ Institute for Bioeconomy Science