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.

Research from this project and others has been showcased in a new website ‘Gamba grass research synthesis’.

Research through the Australian Government’s National Environmental Science Program has helped land managers better understand the scale of the gamba problem, the serious threat it poses to biodiversity and how research can support successful gamba management approaches.

The new website showcases more than 2 decades of research into the invasive weed gamba grass.

You’ll find a sobering case study of the rapid spread of gamba in Litchfield National Park to cover 30,000 hectares, how gamba has significantly increased the cost of fire management to up to $100,000 for a single fire and how fine-scale herbicide application and reducing the frequency of gamba fires are helping rangers successfully manage gamba grass on Mary River National Park.

The research also highlights the cost of not funding gamba management – the longer you leave it, the more gamba spreads and the more costly management becomes.

Data, maps, photos, videos, animations and diagrams are used throughout to present the research in informative and easy-to-understand ways.

This is a ‘living’ website, meaning we’ll keep adding to it with findings from current and future research into this high-priority weed.