Photo: Kristian Bell
Media

Short-term Impacts of the 2019/20 Fire Season

Fire ecologists are meeting online today to discuss the impact of the devastating 2019/20 fire season. Topics range from impacts on Gondwanan rainforests, snakes and koalas; recovery of ground-dwelling mammals; and the effect of the fires on endemic flora like the critically endangered Wollemi Pine. 

Participants available for interview – contact Grace Heathcote; Ecological Society of Australia on 0404 542 523 or media@ecolsoc.org.au

Researchers from Macquarie University have identified which Australian plant species are most at risk of declines and extinction after more than 10 million hectares of Australia burned in the 2019-2020 bushfire season.

Data on the distribution of more than 26,000 plant species were coupled with spatial data like the incidence of drought, previous fire history, and weed and feral animal occurrence. This was combined with information on key traits such as species capacity to resprout after fire, obligate seeding, and growth form.

Of the 26,062 species assessed, 255 had 80% or more of their range burnt and were ranked HIGH for one or more criteria.

“Overall, the interactive effects of fire and drought, damage by feral herbivores and the risks posed to plant populations by short fire intervals emerged as clear factors shaping species potential for recovery,” says Dr Rachael Gallagher from Macquarie University.

“This analysis highlights how cascading hazards combine to inflate risks of population declines,” she says.

The results of the study have informed the work of the Threatened Species Commissioner’s Bushfire Recovery Expert Panel and are also being used to prioritise conservation actions such as listing affected taxa as threatened under the EPBC Act and state legislation, post-fire conservation survey and actions, and restoration and seed-banking efforts.

In addition, a study by scientists with the NSW Department of Planning, Industry and Environment on the impacts of the 2019-2020 bushfires on the last remaining stands of critically endangered Wollemi Pine (Wollemia nobilis) has found that high frequency fire is preventing recruitment and threatening long-term persistence.

An unprecedented fire-fighting operation successfully protected the largest, mature individuals despite some trunk loss and damage due to basal charring and impacts from falling rocks and trees. However most smaller, immature trees suffered complete canopy scorch and a bank of several hundred seedlings and small juveniles may have been eliminated.

“This is our first opportunity since the species’ discovery to observe how wild Wollemi Pines respond to fire,” says Berin Mackenzie from the NSW DPIE.

“Slow growth rates in conjunction with contemporary fire regimes appear to be preventing seedlings and coppices from attaining the minimum escape heights required to avoid total canopy loss during subsequent fires,” says Mackenzie.

“Large stumps succeeded by significantly smaller trunks on mature trees suggest a long-term, continuing decline in tree size and structure consistent with the cumulative impacts of repeated, frequent fires.”

The study concludes that Wollemi Pines require extended fire-free intervals spanning many decades for post-fire recovery, recruitment and persistence. This presents a significant challenge for conservation managers given the predicted increase in the frequency and severity of wildfires.

Wollemi photos available below. All images must be accompanied by credits provided.

Also in this session:

  • Loss of resilience after longwall mining leads to post-fire collapse of peatland ecosystems
  • The 19/20 Queensland Bushfire Season and Post-fire Plant Responses in the Border Ranges (Qld)
  • Fire in Gondwanan Rainforests, impacts and recovery of range restricted threatened flora, north east NSW
  • Interactive effects of logging and wildfire on forest carbon stability
  • Estimating fire impact on koalas – an impact / control design
  • Impact and recovery of ground dwelling mammals from the epicentre of the 2020 Currowan bushfire
  • Impacts of the 2020 wildfires on an endangered snake: insights from a 29 year study
  • A live panel discussion

 

Media releases: www.ecolsoc.org.au/media-and-events/media-releases

On Twitter: #ESAus20 // @EcolSocAus

Conference website: www.esa2020.org.au/

 

 

Phil Lamrock / NPWS – The main Wollemi Pine grove

 

 

 

Phil Lamrock / NPWS – Aerial view of the main Wollemi Pine grove immediately after the fire

 

 

 

John Spencer / NPWS – Scientific assessment of post-fire impacts

 

 

 

John Spencer / NPWS – Charring of Wollemi Pine trunks

 

 

 

Berin Mackenzie / DPIE – One of the first Wollemi Pine seedlings to emerge after the fires

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