GRAEME WORBOYS: Kosciuszko: Post 2020 fire responses

In January 2020 severe bushfires burnt parts of Kosciuszko National Park impacting its National Heritage listed catchment wetlands, fauna and flora values.

The fires also impacted part of Cabramurra, Mt Selwyn ski resort, Snowy 2 engineering equipment and historic structures. In its fire blackened state, feral animals were a major threat to the park, especially the fire area’s 15,000 feral horses. Urgent responses by government are sought.

In early January 2020 major fires entered Kosciuszko National Park on its western boundary and burnt eastwards in catastrophic fire weather conditions. There was a touch of inevitability to these events. During December, fires had been burning in extreme conditions to the north, west and south of Sydney, west of the Great Divide and along the NSW south coast. 2019 had been Australia’s warmest and driest year since records began in 1900 and the rural sector was stressed in a manner that only the worst of Australia’s droughts could achieve. Rivers and streams had dried up, dust storms despatched precious top soil eastwards, regional towns were desperately short of water and many farmers had run out of feed for their stock.

Kosciuszko was also drought stressed. It was dry and the extreme December 2019 temperatures even affected Australia’s highest mountains. Fires burning from the northwest, through agricultural lands, orchards and state forests impacted Kiandra and the Bogong Peaks in Kosciuszko. This large and dangerous so-called Dunns Road fire had moved across the landscape with great speed, burning some homes and properties and had threatened townships. It burnt into Kosciuszko as an upslope fire and under severe wind conditions. It was fast moving, intense and all consuming. It burnt structures and facilities at the Mount Selwyn ski resort, burnt parts of Cabramurra township and Snowy 2.0 equipment was destroyed at the Ravine. The historic Kiandra courthouse was burnt under extreme, blast furnace like heat, leaving only its bluestone walls standing. Caves house at Yarrangobilly was an exception. It was saved by on-site NPWS fire crews assisted by sprinkler systems on buildings installed during restoration works. Some mountain huts were also saved after intensive protection efforts, though some could not be saved.

There were ecological impacts to this great national park. The fires burnt through alpine ash forests regenerating from similarly severe fires in 2003. These grand species propagate through seed and 17 years may not be enough time for the young, regenerating trees to produce new seed. Some remnant older alpine ash would also have been burnt and their associated hollows providing critical habitat for native birds and mammals would have been lost. Frequent fire, higher temperatures and regular droughts were transforming mountain ecosystems. At higher altitudes on the Kiandra plains, fires impacted regenerating snowgums. This species is critical for enhancing water yield for the Murray and Murrumbidgee catchments and too frequent fire would see the loss of these subalpine trees. Native grassland, wetlands and stream side heath were also burnt. Some small grass and heath patches were left unburnt on the Kiandra plain.

Kosciuszko’s native alpine animals and their habitats were impacted by the fires. A thick vegetation cover of subalpine heath and tussock grasses (for example) provided habitat and protection for the endangered Mastacomys, the magnificent Australian bush rat. The 2020 fires removed such protective cover in many parts of Kosciuszko. It also burnt vegetation on the boulder fields near Happy Jacks including the mountain plum pine, a food source of the resident mountain pygmy possums. Kangaroos, wallabies, wombats, echidna’s, possums, bats, birds, snakes, lizards, skinks, frogs, insects, and crayfish are some of the sub-alpine wildlife affected by these fires. Tragically many of these different animals will have been killed. Native fish and platypus in streams will also be impacted by post fire run-off and erosion of ash and burnt soil contaminants into the streams. Grass for red-necked wallabies and wombats in the subalpine burnt areas will be scant, with unburnt patches and new green shoots being important for these animals.

If the fire was not bad enough, native sub alpine species now had to contend with the presence of Kosciuszko’s unwanted introduced animals. It will be a second wave of impacts for the park’s native flora and fauna. Predators were a major issue. Feral cats and foxes benefited directly from bushfires that opened up protective habitat. These voracious animals prey on native subalpine species including endangered skinks, mammals, mountain crayfish and insects, animals not found anywhere else on Earth. There is some hope. These efficient killers have been controlled in small areas of Kosciuszko where endangered species have been protected by the NPWS. This however needs intensive management intervention. Dr Linda Broome’s brilliant protection of the mountain pygmy possum near the Perisher Range resorts included good science; intelligence from wildlife cameras; the use of highly trained sniffer dogs and rubber edged traps. Kosciuszko’s wildlife can be protected from foxes and cats, but realistic resources are urgently needed to undertake this work.

In 2020, without the fire, feral horses represented the single greatest environmental impact agent to the park’s sub alpine and montane ecosystems and water catchments. Grazing impacts by feral pigs and wild deer to native alpine plant species post fire were also an issue. The feral horse population had ballooned from 6,000 (2014) to 19,000 (2019) under anti-national park legislation introduced by John Barilaro of the NSW National Party. Contradicting every premise that an iconic national park and National Heritage listed property stands for, NPWS staff were instructed not to control these destructive feral animals. The park was quickly encumbered with the excessive feral horse numbers. When one heavy horse can trash a mountain stream or a wetland, there is little hope for the native environments of the Kiandra plain – Tantangara area where there is a population of 15,000 horses.

The 2020 fires immediately compounded the feral horse problem. The animals appeared to have survived the fire in great numbers. Now their impacts were more concentrated and the blackened subalpine environment more vulnerable. Islands of unburnt subalpine grassland would be preferentially grazed by excessive numbers of feral horses and any surviving Australian species such as our native wallabies and wombats will be outcompeted. Burnt and blackened wetlands, so important for water yield when recovered, will be trashed. Post fire green shoots will be grazed immediately and the wetland’s associated burnt sphagnum and insipient, top of catchment drainage lines trampled. Thousands of hungry horses will destroy vulnerable post-fire wetlands and headwater streams and many flora species could be exterminated locally. It will mean an on-going vandalism of Australia’s high mountain water catchments.

Control actions for the feral horses are known, humane and effective in protecting the park. They just need to be implemented immediately. NSW Premier Gladys Berejiklian needs to override her deputy Barilaro to authorise and resource Environment Minister Kean and the NPWS to undertake effective feral horse control under the provisions of the 2008 NPWS horse management plan. Pro-brumby supporters will be loud, but in the interests of the park, the catchments and Australian native animals and plants, they will need to be stared down. Single interest groups can have their say but it is the national interest what is most important now. Too much damage to Australia’s National Heritage at Kosciuszko has already been done. Reducing the feral horse numbers is an urgent post-fire action given the severity of the impacts projected.

Dr Graeme L. Worboys is an (Honorary) Associate Professor at the Fenner School of Environment and Society, Australian National University and a recipient of the National Medal with clasp for his bushfire management service.

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