Every year on September 7, National Threatened Species Day is commemorated across Australia to raise awareness of plants and animals at risk of extinction.
There are currently 457 species of fauna and 1348 species of flora listed as vulnerable, endangered or critically endangered under Australia’s Environment and Biodiversity Conservation Act 1999 (EPBC Act). Many of these are found nowhere else in the world.
This is a summary of some of the threats facing mountain species.
On the mainland
Snow Gums
Snow Gums (Eucalyptus pauciflora) are the classic alpine tree of the High Country, generally growing at heights between 1,300 and 1,800 metres asl. Anyone who has visited the Australian High Country will know – and probably love – these trees.
In recent decades, wildfire has been devastating huge areas of the Snow Gum forests, with significant fires in the Victorian High Country in 1998, 2002/3, 2006/7, 2013 and 2019/20. More than 90% of Snow Gum habitat has been burnt at least once in the last 20 years.
The species can survive fire. However, climate change driven fire seasons are leading to more frequent fire, which is causing more death of trees and changes to forest structure. In some instances, localised collapse of Snow Gum woodlands is now being observed. As climate scientist Michael Mann describes it, we are now seeing climate change play out in real time.
We must ask whether we are now seeing the start of the collapse of Snow Gum woodlands, one of Victoria’s iconic vegetation communities.
Alpine Ash
Another of our much loved mountain trees is the Alpine Ash. They are also facing potential ‘community collapse’. After the 2013 Harrietville-Alpine Bushfire, the Department of Sustainability and Environment, now DELWP) and Parks Victoria initiated a rapid response forest recovery program, which aimed to restore Alpine Ash forests that had been burnt and where only limited numbers of parent trees had survived. Since then, the program has been expanded considerably as more areas have been burnt multiple times.
A new report, An Icon at Risk, Current and Emerging threats to the Victorian High Country (available here), produced by Friends of the Earth highlights the many risks faced by the Alps, including the potential loss of the Snow Gum forests. An additional threat to Snow Gum communities stems from the increase in dieback, which is caused by a native beetle but which appears to be supercharged by global heating. Climate change is driving more intense fire seasons and drying out the alpine and valley environments.
Pressures:
Rainfall changes
Temperature
Heatwave
Storm
Fire
Habitat change/loss
Invasive species
Livestock / harvesting
Human-lit fire
Monaro Tablelands
The Monaro tablelands of south-east NSW are characterised by mosaics of grassy woodlands, grasslands and forests. These provide important habitat for a range of threatened plants and animal species, including koalas, spotted-tail quolls and dusky wood swallows, as well as 15 other smaller marsupial species, 95 bird species, 14 species of reptiles and more.
Like most other temperate grasslands and grassy woodlands in Australia, the Monaro ecosystems have declined since Indigenous burning regimes were replaced with livestock and feral herbivore grazing, along with clearing, cultivation and non-native plant invasions.
Tragically, since 2005, ribbon gums that once dominated the rolling plains have died in great numbers. This is likely associated with the Millennium drought, ongoing drying conditions and heatwaves, and exacerbated by invertebrate pest outbreaks. More recently, the catastrophic Black Summer bushfires burned extensive areas across the Monaro.
Widespread tree deaths are not only a loss of habitat for mammals, birds, reptiles and invertebrates, but significantly impact the economy through lack of shelter for livestock during the Monaro’s harsh winters and hot summers. The impacts on the landscape’s aesthetic also affects human well-being.
Pressures:
Rainfall changes
Temperature
Native species interactions
Heatwave
Fire
Habitat change/loss
Invasive species
Livestock/harvesting
Snowpatch Herbfields
The snowpatch herbfields, made up of dwarf grasses and alpine herbs, are one of the rarest and most restricted ecosystems in Australia. They occur only on steep, south-east-facing slopes of alpine and high treeless subalpine zones, where snow persists into the spring and summer growing seasons.
Over the past 50 years, climate change has caused warming of almost 1°C, and substantial decrease in snow amount and depth, cover and persistence in the Australian alpine area. Fire has also become a major force with increased frequency, dry lightning storms and extreme fire weather. And feral horses trample vegetation and cause soil erosion. These pressures, and others, are collapsing the snow patch herbfield, replacing them with larger shrubs and grasses or just eroded ground.
The collapse of the snow patch herbfields highlights the plight of the Australian alpine ecosystems in general. The alps are regional economic powerhouses; visitors to the Australian Alps generate over A$1.3 billion and the area employs almost 20,000 people.
Pressures:
Rainfall changes
Temperature
Storm
Fire
Habitat change/loss
Invasive species
Human-lit fire
Mountain Ash forests
The mountain ash ecosystem in the Central Highlands of Victoria supports the world’s tallest flowering plants. It’s among the world’s most carbon-dense forests, supporting an array of threatened forest-dependent species, and generating almost all of the water for the 5 million inhabitants of Melbourne (as well as communities and agriculturalists north of the Great Divide).
The mountain ash ecosystem is under enormous environmental pressure from widespread and recurrent wildfire, coupled with widespread clear-cut logging. Extensive old growth forests once dominated the ecosystem, but now just 1.16% of the ecosystem (1,886 hectares of 170,400 ha) is old growth. The widespread young forest is highly flammable and at extreme risk of reburning at high severity. This is especially due to increased temperatures and greater numbers of days marked as “extreme” on the forest fire danger index.
The collapse will have severe economic and social effects. The value of water from the ecosystem is 25.5 times greater than the value of the timber generated from the same ecosystem. The collapse of the ecosystem also poses an enormous threat for long-term carbon storage, biodiversity conservation and the billion-dollar tourism industry in regional Victoria.
Pressures:
Rainfall changes
Temperature
Fire
Habitat change/loss
Invasive species
Other
In lutruwita/ Tasmania
The Tasmanian Wilderness World Heritage Area covers 15,800 square kilometres. One of its key values is the high concentration of ancient invertebrate animals and plants endemic to Tasmania (often called “palaeoendemics”). An iconic example is the genus Athrotaxis in the conifer family, which is considered one of the oldest surviving plant lineages on Earth — a living fossil.
There are two existing species of Athrotaxis: Pencil pines (Athrotaxis cupressoides) and king billy pines (Athrotaxi selaginoides). Both are very slow growing and can live for more than 1,000 years.
Like other palaeoendemics, Athrotaxis species can’t tolerate frequent or intense fire, and are restricted to fireproof landscapes. Around 30% of the range of king billy pines have been lost in the last 200 years, and half the pencil pines were burnt in the summer of 1960/61 by uncontrolled fires set by graziers to renew grasslands during an intense drought.
Climate change now threatens these and other palaeoendemic species through increased fire activity due to more dry lightning storms and drought. In January 2016, lightning storms ignited numerous fires that destroyed about 1% of the remaining pencil pines. These trees are unlikely to ever return. The loss of palaeo-endemics will profoundly diminish the region’s natural and cultural values.
Securing the survival of palaeoendemics under climate change requires costly management interventions. These include establishing fire breaks, targeted planned burning to reduce fuel surrounding the palaeoendemic refuges and active restoration programs.
Mountain Journal 
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