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snow gums

‘They offer great beauty. They offer shelter. They nurture us.’

Across the Australian high country, the snow gum woodlands are facing an existential threat from dieback and climate change driven fire regimes.

These threats are detailed here, as are some potential solutions.

While the loss of these forests would have major physical and ecological impacts on mountain environments, what would it mean for our personal connection to the high country? For me these trees are an essential part of life in the mountains. When I drive or walk up from the valley and have a wander among old trees, I feel like I have come home. I know these forests have been here for time beyond our imagining:

Continue reading “‘They offer great beauty. They offer shelter. They nurture us.’” →

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‘Long-unburnt snow gum forests are now exceedingly rare’.

Across the mountains of south eastern Australia, climate change is already driving profound change. In many places in the high country of NSW and Victoria, snow gum forests are facing a double sided threat: dieback, caused by a native beetle is killing individual trees, and climate change driven fire regimes are devastating vast areas of forest. Climate change, drought, insects and soil microbes are all thought to contribute to dieback. The spread and impacts of the beetle appear to be super charged by climate change (more beetles are surviving because of milder winters and more mortality of water stressed trees in summer).

More frequent and intense wild fire also poses an existential threat to the survival of snow gum woodlands and forests. A new report reveals the scale of the fire impact on these forests in the Victorian high country.

In the paper ‘Long-unburnt stands of snow gum (Eucalyptus pauciflora Sieber ex Spreng) are exceedingly rare in the Victorian Alps: implications for their conservation and management’, John Morgan, Michael Shackleton and Zac Walker from the Research Centre for Applied Alpine Ecology at La Trobe University highlight that ‘Long-unburnt snow gum forests (now) comprise less than 1% of snow gum forests in the Victorian Alps. We identify where long-unburnt snow gum stands persist in the Victorian Alps and outline why management intervention is necessary to protect unburnt refuges and, more broadly, to allow mature/adult stands (such as occur on the Baw Baw Plateau) to develop into future old forests’.

Continue reading “‘Long-unburnt snow gum forests are now exceedingly rare’.” →

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Welcome coverage of threats to snow gums in The Age

You may have seen today’s story by Miki Perkins in The Age here.  It considers the threats posed to snow gum woodlands (and other mountain forests) by more frequent and intense bushfires.

The story says ‘the global climate crisis, driven by humans burning fossil fuels, has brought a new threat to these mountain peaks: more frequent and more intense bushfires.

Because snow gums have not evolved to cope with these conditions, experts say the nature of Australia’s high mountain landscapes are changing, and the ecological collapse of snow gum woodlands – the abrupt decline or change of this ecosystem – is happening before our eyes’.

Continue reading “Welcome coverage of threats to snow gums in The Age” →

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“Ecological collapse is likely to start sooner than previously expected”

The Guardian recently reported that ecological collapse is likely to start sooner than previously expected, according to a new study that models how tipping points can amplify and accelerate one another.

Based on these findings, the authors warn that more than a fifth of ecosystems worldwide, including the Amazon rainforest, are at risk of a catastrophic breakdown within a human lifetime.

“It could happen very soon,” said Prof Simon Willcock of Rothamsted Research, who co-led the study. “We could realistically be the last generation to see the Amazon.”

The research was published on Thursday in Nature Sustainability.

Here in Australia we are starting to witness tipping points, where specific ecosystems are being pushed beyond their capacity to recover from impacts like fire, then experiencing ecological collapse whereby an existing system – for instance an alpine ash forest – collapses and is replaced by something else (in the case of alpine ash it might be a mix of grass and shrubs).

Continue reading ““Ecological collapse is likely to start sooner than previously expected”” →

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A rescue plan for the Snow Gums

The first time I skied in the backcountry in the Rocky Mountains in Colorado, I was shocked by the dieback of pine trees. While I had read a lot about the beetle that is devastating a lot of the conifer forests in that part of the world, it was a shock to see it running through entire hillsides. Even in the glorious deep powder of a northern winter, I was reminded of the terrible ecological changes that are rippling through ecosystems across the planet.

Back home I was familiar with a similar pattern. Across the mountains that I love I could see the Alpine Ash in freefall as more frequent fires were starting to see local collapse of Ash communities. More regular and intense fires has led to loss of seedlings before they can produce seed. The situation is so dire that the Victorian government has an aerial seeding program to try and keep Ash populations viable.

Meanwhile, at higher elevations in the snow gum country, a double sided threat is charging through the forests: dieback, caused by a native beetle is killing individual trees, while climate change driven fire regimes were devastating vast areas of the high country.

Once you see these changes, you can’t unsee them. The endless stands of grey dead trunks. The loss of the old trees. The thickets of flammable regrowth. Every trip to the mountains reminds you that we are seeing ecological collapse in real time.

Continue reading “A rescue plan for the Snow Gums” →

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Quantifying the climate cost of the Black summer fires

We know that climate change is resulting in increased fire severity and extent in Australia’s temperate Eucalyptus forests. While Eucalyptus forest communities are generally adapted to the presence of fire and in some instances need irregular fires, as the gap between fires become shorter and fires become more severe, there are obvious biodiversity impacts. For instance, forests are already changing – especially the alpine ash and snow gums, which are in a state of decline and even ecological collapse in many parts of the high country.

There is also the question of the how carbon released during these fires adds further fuel to climate change. While the general understanding is that carbon lost to the atmosphere during a fire is drawn down again in subsequent regrowth, is climate driven fire seasons causing more carbon to be lost into the atmosphere, thereby making climate change worse?

New research (Tree mortality and carbon emission as a function of wildfire severity in south-eastern Australian temperate forests, to be published in the journal Science of the Total Environment – a summary is available here) considers these issues and fills some significant gaps in our knowledge about the links between fire and its contribution to climate change.

Continue reading “Quantifying the climate cost of the Black summer fires” →

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Where are the old 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.

Continue reading “Where are the old snow gums?” →

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The multiple threats to the survival of snow gums

For years now, Mountain Journal has posted about the multiple threats posed to our mountain environments which link back to climate change, including increased frequency of fire, higher temperatures, more frequent drought, and more impact from dieback (which is a natural phenomenon which is being super charged by global heating). These have also been documented in the Friends of the Earth report An Icon at Risk.

Its always good to see mainstream news coverage of these threats.

Genelle Weule, writing for ABC Science, has written an indepth piece which covers these threats.

Continue reading “The multiple threats to the survival of snow gums” →

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The elders among the devastation

If you visit this website often you will be familiar with the depressing stories about the decline of the wonderful snow gum. Between dieback and more intense fire seasons, the iconic tree of the high country is in decline.

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. If you’re interested in the detail of this, check these articles.

But we still have a lot of amazing older and mixed age snow gum forests. And in the depressing reality of the 21st century, it’s good to celebrate and love the places that are still intact. Please share your favourite spots.

Continue reading “The elders among the devastation” →

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Documenting loss of Snow Gums in the VIC Alps

The recent The IPCC WGII Sixth Assessment Report included details about the threat posed by climate change to Snow Gum woodlands (story here). Mountain Journal has been recording the local loss of Snow Gum woodlands across the Australian high country for several years now.

In a welcome sign, the last two summers have been mild and wet, and this has led to reseeding in some previously burnt areas of Snow Gums after years of no growth. However almost every trip to the higher mountains reveals new areas that have been burnt to the point of ecological collapse.

Continue reading “Documenting loss of Snow Gums in the VIC Alps” →

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IPCC report points to collapse of Alpine Ash and Snowgum woodland

The IPCC WGII Sixth Assessment Report has just been released (and is available here).

The take home message is:

Further climate change is inevitable, with the rate and magnitude of impact largely dependent on the emission reduction pathways that we choose. Time is running out if we want to act.

The final sentence of new IPCC report is: “The scientific evidence is unequivocal: climate change is a threat to human well-being and the health of the planet. Any further delay in concerted global action will miss a brief and rapidly closing window to secure a liveable future.”

The Chapter on Australasia (available here) has a considerable amount of detail on likely impacts on mountain areas of south eastern Australia and lutruwita/ Tasmania. Some of these are summarised below. It looks at both observed impacts and predicted future impacts (applying a level of certainty to each of these).

Continue reading “IPCC report points to collapse of Alpine Ash and Snowgum woodland” →

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Yet another warning that we need to act now to protect forests from climate change-driven fire

According to a report released by the United Nations Environment Program and environmental not-for-profit organisation GRID-Arendal, as climate change continues to destablise global weather patterns, we can expect up to 50% more wildfires by the turn of the century.

This will impact on us locally and the mountain forests we love.

One example of this is Alpine Ash forests, which have been heavily impacted by fire in recent decades. The same threats are starting to cause local collapse of Snow Gum woodlands.

Continue reading “Yet another warning that we need to act now to protect forests from climate change-driven fire” →

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