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| Mountain Ash forest (Flickr/sitkasitchensis) |
The Central Highlands of Victoria are home to the world’s tallest flowering plants, the Mountain Ash, and one of Australia’s most endangered mammals, the Leadbeater’s Possum.
Both are threatened by ongoing clear-felling and bushfires.
To ensure their survival, I would argue we need to create a new national park, not only to protect possums and forests, but carbon stocks, water supplies, and lower the risk of bushfires. Here’s the evidence.
Extinction and collapse
The central highlands region of Victoria is located around towns such as Healesville, Warburton, Marysville and Woods Point.
The region includes the vast majority of remaining (and declining) Leadbeater’s Possums, Mountain Ash, the most carbon dense forests in the world; and supplies a large proportion of the drinking water for the city of Melbourne.
But the Mountain Ash forests are threatened by recurrent and widespread industrial clearfell logging and major fires (including the Black Saturday fires of 2009).
The result is that we now have 1,886 hectares of old growth forest, spread across 147 different patches. This is estimated to be 1.5-3% of the historical area of old growth forest.
The population of large old hollow-bearing trees has collapsed. These are a critical habitat for the animals that use them, including Leadbeater’s Possum. There is a high risk that the possums will become exinct in the next 20-40 years.
And as forests regrow from logging, they are at increased risk of re-burning at high severity.
Leadbeater’s Possum and Mountain Ash forests have persisted for tens of millions of years, including through major wildfire events. But in just the last few decades the possum is at risk of extinction, and the forests are at risk of ecological collapse.
The threat of clear felling
The one factor that has demonstrably changed this ecosystem in the past century and created these risks has been intensive and widespread industrial clear felling. Clear felling has a number of significant detrimental effects in Mountain Ash forests.
Clear felling kills animals outright. Logged areas are unsuitable for animals that depend on hollow-bearing trees for over 150 years.
Logging accelerates the loss of tree hollows; and we know that these hollows can’t be replaced by nest boxes. Logging stops old growth forest regenerating, and it increases the fire proneness of the forests.
A bigger reserve
To preserve Leadbeater’s Possum, and in fact the entire Mountain Ash forest ecosystem, we need a bigger national park in the central highlands.
There are already reserves and national parks in the area, but these need to be expanded and connected to deal with the threats facing Leadbeater’s Possum and Mountain Ash forests.
The new national park is important as it removes the key process - industrial clear felling - that is threatening both Leadbeater’s Possum and Mountain Ash forest.
Why do we need to expand our reserves in the area?
First, the current reserve system is too small to support a viable population of Leadbeater’s Possums, particularly if there are more fires in the next 50-100 years.
Second, a large ecological reserve provides a greater chance for natural fire regimes and growth of large old trees to be restored.
Third, as Mountain Ash forests store vast amounts of carbon, a new national park will be critical to maintaining carbon stocks. The park would therefore be critical to any policy to reduce carbon emissions.
Our studies clearly indicate that clear felling significantly depletes carbon storage in Mountain Ash forests whereas allowing stands to grow through to a mature or old growth significantly increases carbon storage (even in the event of a major wildfire).
Fourth, water yields from Mountain Ash catchments are maximised when forests are dominated by old growth stands.
Location, location
The new park needs to connect key areas of habitat for Leadbeater’s Possum, and also connect existing reserves. Connectivity like this promotes the dispersal of the possums through the forests, including those recovering after wildfire.
The national park must encompass areas of existing old growth forest and also areas where environmental modelling indicates old growth will develop in the future.
The park must also be big enough to be larger than major disturbance events such as wildfires. This will ensure there is sufficient habitat to support viable populations of Leadbeater’s Possum.
At the same time as creating the park, pulp and timber yield from the the Mountain Ash forests must be reduced.
Mountain Ash forests have already been over-cut, and to maintain sustained yield from the forests and set aside the Giant Forest National Park will even further increase over-cutting. This is because it will concentrate indutsrial clearfelling on a reduced area of available forest.
Economic benefits
A new Giant Forest National Park could be a major economic boost for Victoria. It could be particularly helpful for regional economies like those around Marysville still rebuilding after the 2009 wildfires.
Victorian governments have never seriously advertised the fact that, within 1.5 hours from the MCG, you can find the world’s tallest flowering plants and some of the most stunningly beautiful environments on the Australian continent.
The park will need some seed funding to establish and maintain walking tracks, huts, caravan parks for grey nomads as well as other visitor infrastructure. The benefits of such investment - when done strategically - have been documented by many authors over the past few decades.
Moreover, investments in tourism would be in stark contrast to the significant loss-making native forest paper pulp and timber industries in eastern Australia.
Large ecological reserves are at the core of any credible approach for forest biodiversity conservation plan. This is particularly true in the case of Victorian mountain ash forests.
The incoming federal government’s policy on forests is broadly to: “stop any further lock-ups” of forests.
But the scientific and other evidence supporting the need for a new national park in the wet ash forests of the Central Highlands of Victoria is both overwhelming and compelling. Moreover, there are strong social and economic arguments to establish a new Giant Forest National Park.
David Lindenmayer has received funding from the Australian Research Council.
This article was originally published at The Conversation. Read the original article.
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