Re-thinking fire management in Kakadu

New research using decades of time-series monitoring data from TERN has identified significant problems with the current state of fire management in one of Australia’s premier National Parks: Kakadu. The findings of this research will be used by park managers to plan and deliver more sustainable and ecologically appropriate fire management in the reserve.
New research using TERN environment database indicates that the impact of fire on the ecology in Kakadu National Park is “more dire than previously thought”

New research has evaluated the current state of fire management for biodiversity conservation in Australia’s premier, and most publicly funded savanna reserve, Kakadu National Park.

The assessment, just published in Ecosphere, draws on long-term data on fire incidence and severity, and vegetation and fauna collected at the 220 monitoring plots of the Three Parks Savanna Fire Effects Plot Network, part of TERN’s Long Term Ecological Research Network (LTERN).

To assess management effectiveness of current fire management practices in the National Park, researchers used LTERN data combined with satellite-derived fire and habitat mapping data to model responses of vegetation and fauna.

“We now know that contemporary fire regimes, especially the high frequency of large, relatively severe late season fires, have contributed to the declines in small mammals and impacted fire-sensitive flora in the park,” says Mr Jay Evans of Charles Darwin University’s Darwin Centre for Bushfire Research.

“But the performance metrics we used to quantify this indicate that the impact of fire on the ecology in the reserve is more dire than previously thought.”

Beyond the threshold: quantifying unsustainable fire management

The research team used ecological performance threshold metrics to assess how past and current fire regimes are impacting on Kakadu’s ecology.  A series of thresholds, or ecological tipping points, relating to fire’s impact on Kakadu’s ecosystems were assigned and the data used to assess their status.  Moving beyond a threshold indicates significant ecological impact.

“Of 14 assessed performance threshold metrics, two were within acceptable thresholds at the end of 2015, and none had improved materially over the decadal assessment period,” write Jay and his co-authors in the paper.

“For example, by the end of 2015 it was observed that just 6% of woodland habitat in lowland and 23% in upland situations had remained unburnt for longer than three years and 98% of mapped fires in lowland and 87% in upland habitats were >1 km2 in extent.”

Bird’s-eye view of a prescribed burn in Kakadu National Park

Savanna burning greenhouse gas emissions abatement projects need to be explored

“Our research has shown that areas which experience low intensity fires earlier in the dry season are more ecologically healthy than those impacted by late season severe fires,” says Professor Jeremy Russell-Smith, also of the Darwin Centre for Bushfire Research and Co-Leader of the Three Parks Savanna Fire-Effects Plot Network within LTERN.

“By prescribed burning areas of the parks early in the dry season, park managers are trying to reduce the extent of fires later in the season”.

But, such seasonally intensive, fine-grained adaptive fire management for biodiversity conservation is incredibly difficult and expensive.  So, in addition to creating a more environmentally sustainable fire management program, the research also recommends landscape-scale carbon sequestration and savanna burning emissions abatement projects as an additional management tool.

“We are very keen to promote formal carbon-market savanna burning approaches in the Northern Territory, similar to those undertaken in Western Arnhem Land through the West Arnhem Land Fire Abatement [WALFA] project, which have proven very successful environmentally, economically and culturally,” says Jeremy.

Under WAFMA ConocoPhillips pays around $1million a year to Indigenous ranger groups to undertake savanna fire management to offset the carbon emissions from its liquefied natural gas plant in Darwin Harbour. Since 2006 the project has abated over 100,000 tonnes of CO2 annually—equivalent to around 14,000 homes’ electricity use for a year.

“Such projects provide traditional custodians and knowledge-holders with a very viable means to stay on the land they care for and earn an income from it in the new carbon economy,” says Jeremy.

Essential research for improved park management

The realisation of the paper’s management proposals may come sooner than expected thanks to the direct involvement of park managers in the research.

Anthony Simms, of Parks Australia, was a co-author of the paper and says that the collaborative, integrated nature of this work is key to efficiently translating the science into policy and practice.

“We [Parks Australia] are intimately involved with the scientists, statisticians, rangers, Aboriginal custodians, school and university students, and agronomists conducting research at Kakadu,” says Anthony. “There are cost savings, but more importantly this inclusiveness means that park managers understand fires in savannas and how they affect biodiversity, and are better placed to implement appropriate management in policy and practice.”

As extreme fires are likely to become more frequent in Australia it is essential that the long-term collection of data within Kakadu National Park is continued.

Without the continuity and availability of long-term biodiversity and vegetation data the potential for ongoing collaboration of these experts and their conservation and research agencies is servery undermined. But this is vital if we are to sustainably manage our reserves and retain healthily functioning ecosystems. And is a challenge for Australia more generally.

  • This research draws on the data collected from the 220 permanent monitoring plots of the Three Parks Savanna Fire Effects Plot Network, a member of TERN’s Long Term Ecological Research Network (LTERN).
  • Data on fire incidence and severity, and vegetation and fauna across habitats in Litchfield, Kakadu and Nitmiluk national parks are available via TERN’s Data Discovery Portal and the LTERN data portal.

The plots in the Three Parks Savanna Fire Effects Plot Network, which forms part of TERN’s Long Term Ecological Research Network (LTERN)

Published in TERN newsletter July 2017

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