Why Gamba Grass is a serious threat to the Top End of Australia.
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Uncontrolled Gamba grass spreads quickly Roadsides and other disturbance corridors (e.g fire breaks) have been the major conduits for the spread of Gamba in the NT. Seed is commonly spread via machinery(e.g slashing, grading), but may also spread by wind and the thermal currents in fires. Unassisted, Gamba may spread up to 110 m per year through native vegetation. |
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Gamba grows into tall, thick clumps that choke out wildlife and other vegetation. It gets so thick that one has difficulty even walking amongst it.
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All this grass creates enormous fuel loads for fires. Gamba grass
fuel loads up to 21 tonnes per hectare have been measured around
the Coomalie region. 3. Gamba grass creates much hotter fires |
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When this huge fuel load burns it generates up to 8 times the intensity of native fires, with flames up to 15-20 m, reaching above the tree canopy. This is compared to early dry season native grass fires which have flames of just 1 m. A fire at Rum Jungle in 2004 traveled 5 km in just 25 minutes, destroying bushland and property in its path. This is totally different behavior to normal Top End native bushfires.
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4. Hotter fires may kill native trees Repeated Gamba grass fires can kill native trees, potentially replacing diverse bushland with just grasslands of Gamba. Research has shown that in some areas south of Darwin, the tree canopy has been reduced to half after just five years of Gamba grass fires. 5. Hotter Gamba grass fires pose a fire hazard threat to buildings & people |
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Because Gamba grass fires travel faster than normal Top End bushfires this creates a serious threat to buildings and people. Over the last few years there have been several incidences of Gamba grass destroying sheds and other buildings. More severe losses have been avoided thanks to the efforts of bushfires council, but if the Gamba problem gets worse, the losses of property are likely to become more regular.