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The alpine ash (Eucalyptus delegatensis) – called ‘Woolybutt’ in Victoria – is the classic tree of the sub alpine forests and tends to be replaced by snow gum woodlands at higher elevations. In Victoria, it occurs at altitudes between 900 and 1500 metres. These are the trees you drive through as you leave the valley towns and head into the mountains.

Snow gums (Eucalyptus pauciflora) are the classic alpine tree of the mainland, generally growing at elevations between 1300 and 1800 metres and ending at the treeline where the true alpine zone becomes dominant. To describe their character, you would say charismatic. Beautiful, diverse and interesting. I have never seen two snow gums that look alike.

Like other eucalypts, snow gums are fire adapted – they don’t mind a burn. Depending on the severity, they may simply survive the fire, or they’ll regenerate from seed, by epicormic shoots below the bark, or from lignotubers at the base of the tree. A lignotuber is a woody swelling of the root crown possessed by some plants as a protection against destruction of the plant stem, such as by fire.

However, as the climate gets hotter due to human-induced global warming, we are seeing an increase in the frequency and severity of fires. There have been significant fires in the Victorian High Country in 1998, 2002/3, 2006/7, 2013 and 2019/20. Much of Kosciuszko National Park was burnt in 2003 and 2019/20. Southeastern Australia suffered a decade-long drought which has increased the severity of fires since the turn of the 21st century.

What this means is that in many instances, snow gum forests are being pushed beyond their ability to recover. After one fire you will often see rapid regrowth of seedlings or sprouting from the base or branches. But the regrowing forests are often densely packed and burn hot if they experience a second fire. Multiple fires can lead to the death of the parent trees and seedlings that grew after the first fire.

In many areas, we are now starting to see ecological collapse in these alpine forests.

This means that the snow gums are being pushed beyond their ability to recover and being replaced by grasses and shrubs. The original form of the forest – and the graceful old trees – are lost, as are the many benefits that come from there being mature forests; from important habitat for birds and other animals to better holding of the snow pack well into spring so that rivers receive a steady stream of water from the mountains. Mature trees have been shown to increase snowpack accumulation and moderate melt, making snow gum critically important to the hydrology and water resources of southeast Australia.

Ridge after ridge of bleached grey ‘ghost forests’ are replacing the snow gum forests we know and love. This is climate change in real time.

This has huge implications for the ecology. It also impacts us. Having spent much of my life skiing and walking among snow gums, I am seeing the trees get younger over time. Craig Hore from Parks Victoria’s reflects on his years of work in the High Country. In his early days as a ranger he could drive through older forests for hours but now so much of the Alpine National Park has been badly impacted by fires that, “I doubt we will ever see those old forests again.”

It is the same story with the alpine ash. The situation is so bad that after the 2013 fires in Victoria, the state government launched an Ash Restoration Project, which collects seed from trees and then sows areas burnt in wildfires where the trees have been killed off. We know that nature is incredibly resilient, and over time these forests will come back from even the most intense fire. But now they are facing a world where recurring fire threatens their very existence. It is mind boggling to think we need to intervene on a landscape scale to try and keep an entire forest community viable in the wild.

But that is where we are at.

We now also need to intervene if we want to see the old snow gum forests remain.

More than 90 per cent of snow gum woodlands have burnt at least once in recent decades. Knowing that snow gums are susceptible to frequent fire, a meaningful intervention would be to do our best to exclude fire while these forests recover. We need to better understand where the pockets of remaining old snow gums are, and then commit to protect them from wildfire. We also need to ‘regrow’ old forests – that is, exclude fire over many decades as recovering forests turn into mature forests.

One significant piece of research that should inform our understanding about fire on snow gum forests looks at the impacts of fires on Lake Mountain and the Buffalo Plateau in Victoria. The report – written by Fiona Coates, Philip Cullen, Heidi Zimmer and James Shannon – used the long unburnt Baw Baw Plateau as an example of what these systems could be like in the absence of fire events.

The report found that:

Repeated fires change the character of snow gum forests, creating a multi-stemmed forest of shorter trees. That is, forests get denser with more of a ‘mallee’ aspect to how the trees grow. They call this “potentially irreversible degradation of stand structure”, which has already happened to the extent that old growth snow gum forests are now rare.

Repeated fires can inhibit the ability of trees to store carbon above the ground.

The researchers repeatedly note there are serious doubts about the value of fuel reduction burning in these forests. They note that low intensity fires still negatively impact on tree resprouting ability.

They conclude that “fire exclusion is imperative to preserve landscape quality and representation of long unburnt snow gums.”

Even areas that have been subjected to hot and destructive wildfire, such as on the Lake Mountain plateau during the 2009 Black Saturday fires, can be expected to recover, provided we can keep fires out of these systems. However, this will take time. They suggest it will take the forests at Lake Mountain at least 70 years to return to pre-fire structure. No specific management needs to be undertaken to aid this process beyond excluding fires.

We know that without action to radically reduce greenhouse gas emissions on a global scale, we will continue to experience ever greater warming and hence longer and more intense fire seasons. Former NSW fire chief Greg Mullins recently acknowledged that further warming is “baked into the system… until 2050” but what happens after was “entirely reliant” on what the government does to reduce emissions today.

A key message to understand is that there is still time to act.

“The people who love our Australian snow – who feel its call – base their lives, their communities, their income, their joy, their identities around it. They would be bereft to consider that this incomparable place could die,” offers science writer Dr Jonica Newby. “The dying snow gums are to our snow-lands as the bleaching corals are to the Barrier Reef. A plea from the emergency ward, a desperate call to save this place before it is too late. I cannot bear to contemplate what will happen if we ignore this call.”

You can read the Friends of the Earth’s report into the state of the Victorian High Country here. You can support the work of several groups fighting to save the High Country here and you can sign a letter to the Victorian Environment Minister here.

If you’re feeling more adventurous, Friends of the Earth are offering guided walks through the High Country. The first on November 5 is to the headwaters of the Little Dargo River near Mount Hotham. The second on November 6 is a citizen science field trip to Mt. Tabletop to investigate the ongoing impacts of the Black Summer bushfires.