Fire and weeds in the Top End

This research project has shown:

  • Gamba grass has rapidly expanded in the park since 2014, with infestations now covering ~30,000 ha.
  • This is the largest gamba grass infestation in a national park in Australia.
  • Without intensive weed control, we predict gamba grass will cover more than 42,000 ha within a decade.
  • We describe 2 options for mangers to protect highly valued environmental and tourism assets:
    1. eradicating 594 ha of gamba grass from the existing eradication zone on Tabletop Range, predicted to cost $825,000 over 5 years
    2. eradicating 801 ha of gamba grass in a much larger eradication zone, to better protect park assets, predicted to cost $6.6 million over 5 years.
  • Significant investment in intensive gamba grass control and monitoring is needed to protect assets in the park.

Read more about these findings in this scientific paper and accompanying factsheet and media release.

This animation of maps from Rossiter-Rachor et al. 2023 shows the surveyed and modelled distribution of the weed gamba grass in the Northern Territory’s Litchfield National Park from 2008–32.

  • Mary River ranger among recovering trees in previously gamba-infested landscape. Photo NESP Northern Hub.
  • Tree death from gamba invasion and subsequent fires (aerial), photo NESP Northern Hub.
  • Recovering native savanna in Mary River National Park, photo NESP Northern Hub.
  • Person standing in front of tall stand of gamba. Photo NESP Northern Hub.
  • Gamba grass fire. Photo Sam Setterfield.
  • Measuring gamba grass fuel loads, photo Fiona Freestone.
  • Collecting soil samples, photo Daisy Lippiatt.
  • Tree death after gamba grass fire, photo Natalie Rossiter-Rachor
  • Gamba grass tussocks, photo Michael Lawrence-Taylor
  • Checking seed germination, photo Natalie Rossiter-Rachor.
  • Gamba grass tussock
  • Gamba grass tussocks, photo Michael Lawrence-Taylor