Friday, October 8, 2010

Keppel Lookout over Marysville, October 2010

Keppel Lookout, south of Marysville, the epicenter of the public effect of bushfire. The Cathedral Ranges are seen further north. As of late 2010, the effects of fire are still visible.

Stephen Smith from the local Department of Sustainability & Environment talked to us about some of the observed ecological responses to fire. Some devastated, some rejuvenated. Positively, some endangered species, such as the Buxton Gum, fall into that latter category, which is apparently flourishing after the disturbance February 7th, 2009, provided.

The story of the Barred Galaxias (Galaxias fuscus, right) is particularly fascinating. Prior to the fires, the greatest threat to the fish was due to colonisation of its habitat by introduced Brown and Rainbow Trout. Incredibly, what preserved the fish's distribution in the streams near Marysville was due to a poorly constructed culvert that acted as a trout barrier. It's incredible that, occasionally, human negligence and poor engineering skills can have a positive effect on an endangered species.

The culvert has since been repaired, and replaced with a constructed trout barrier.

Three Years Before The Fires

Ever since the Black Saturday bushfires wiped out the majority of the Kinglake National Park and the Wallaby Creek Closed Catchment, I've heard lecturers and friends talk about those forests in eulogistic tones, seemingly regretful that they could not do anything to personally spare those 300-odd year old Mountain Ash (Eucalyptus regnans) trees the girdling flames of February 7th 2009.

I was mourning them, too, as I knew that I had spent hardly any time amongst them, and as far as I could remember, had never documented them.

However, perhaps due to the general haze and confusion of undergrad, I had forgotten that I had actually been taken on a field trip to those forests in 2006 by Dr. Peter Ades as part of a Trees & Forests subject.

After some digging around on some old external hard drives, I managed to find a set of photos I had taken on that field trip.

If Peter is correct, because of the dismal crash of forestry enrollments at The University of Melbourne between 2005-09, we would have been the last cohort of forestry students to have visited Wallaby Creek before it was burnt.

It was in the Wallaby Creek Closed Catchment, which is to the west of Kinglake National Park, where some of the tallest living flowering plants in Victoria, let alone the world, resided. These Eucalyptus regnans were the product of a bushfire sometime in the 1700s, and by the sheer luck of exclusion from countless fires, including Black Thursday, Friday and Ash Wednesday, they were never engulfed in flames until only one year ago.

In the tallest trees stakes, the top of the list is still dominated by a few trees in regrowth Tasmania. For the mainland, however, it is likely that the tallest living trees are now those in the Dandenong Ranges along Sassafras and Clematis Creek.

What is most striking about a 300-year old Mountain Ash forest is largely aesthetic - due to the vast distance between the height of the understory and the sky-scraping upper stratum, it seems as the Mountain Ash are not trees but pillars holding up the sky.

Futhermore, natural thinning of these forests result in there being surprisingly few actual trees per hecatre, which is interspersed with a greater number of rainforest species and a reduced dominance of wattle.

All is not lost, of course - the Wallaby Creek forest isn't 'destroyed', per se, but rather the time has come for the next cohort of trees to grow between the marbled-toned pillars of their parents. As to whether, however, the next 300 years offers a climate stable enough for them to reach their prior height and maturity will be no more than a game of speculation.

While these two images aren't of the same forest, and represent different age classes, it's the same forest species, and gives you something of an idea of the before and after effect of a major bushfire event.

Sunday, February 7, 2010

In Memory of Black Saturday, Feb. 7th, 2009

A firebreak currently being constructed along the ridge of the O'Shannassy catchment and the
forest that eventually leads toward Marysville. Some may scoff at the importance of it now, well after the
fires that devastated community forest and wildlife, but it's purpose is not for now, but in 70 years time, when
'Black Saturday' means as much as 'Black Friday' did over a year ago.

Tuesday, January 26, 2010

North-Eastern Forests of Victoria

Nothafagus cunninghamii (Myrtle beech) forest, near Mt. Donna Buang, January 2010

Eucalytpus regnans (Mountain Ash), near Marysville, January 2010

Eucalyptus pauciflora (Snow gum), January 2010

Lake Mountain, January 2010

Marysville, January 2010

Recent logging coup, near Toolangi, January 2010

Wednesday, January 20, 2010

The Old Growth That Goes Unnoticed

It's hard not to join in the chants when they come to town - mainly because it's something of a no-brainer. Old growth forests, those mythic stands of trees, whatever species they may be (if we even care in the first place what species they are), touch something deep within us that compel us to argue for them to be conserved, protected and revered. We don't care for definitions, all we care is that they're old, they're forests, and they're safely locked in reserves far from the touch of humankind.

It's a noble cause, and to paraphrase the eminent Victorian forest ecologist David Lindenmayer, we are living in a time when we shouldn't have to log or destroy our old growth forests. It is a mark of the truly civilised society, then, that the soil shall never shake with the vibration of a falling giant ever again.

But there is a question that hangs over these presumptions that no one seems to consider - what happens when the old growth dies, of natural causes? In the case of Australian old growth, the majestic Eucalyptus regnans tends to live for around 400 years - dwarfed by the 2,200 years of it's rival-in-height, Sequoia sempervirens. Are we prepared to let go of old-growth, if that loss occurs free of the hand of man or bushfire?

The greatest issue concerning Victorian old-growth forest is not so much as to do whether it is adequately mapped and protected, or whether the loss of old growth would represent a loss of a vast and efficient carbon sink. As Tim Flannery noted in his 2003 Quarterly Essay 'Beautiful Lies', it may very well be that there is an unfair level of devoted attention paid to them when it comes to debates about sustainable land management.

It's a tricky argument, and you're not likely to garner many friends (of the earth - ha!) while pursuing it - it is too easy a sentiment to be appropriated by anti-conservationists as an argument for no-holds-barred native forest harvesting. However, there needs to be a level of reconsideration when it comes to old-growth forests. As Tim Low pointed out in his 2003 novel 'The New Nature', the notion of wilderness can, at times, be an unhelpful idea - potentially even a "dangerous myth", one of the "biggest buzz words in history", an "idealised view of nature [speaking] strongly to people disillusioned with city values."

In my interpretation, the most dangerous thing about "wilderness" is that it exiles nature to that which lives outside the city limits. And thus, everything in and around our suburban gardens, city streets, and rivers - indeed, all that is closest to our hearts and homes - aren't given the due weight they deserve. This is particularly so in the case of the urban forest.

In 2007, Randy Stringer from the University of Adelaide presented a paper at the annual Treenet Symposium titled 'The Benefits of Adelaide's Street Trees Revisited'. Some of his general conclusions included the observation that trees in Adelaide's urban landscape provide not only aesthetic value, but without them, summer temperatures in the city would be 0.5-2.0 degrees Celsius warmer, translating to a per household per year air conditioning energy consumption
increase of $20. This occurred alongside stormwater reduction, carbon dioxide sequestration and air pollution reduction.

However, one of the most interesting remarks was that, all in all, older, larger street trees in urban landscapes can provide up to 60 times the benefits of younger smaller trees. Therefore - we need old growth not only in wilderness reserves, but in our cities too. This is a great challenge - it requires our planning to take account the next 50 years, and an intelligent overlap between young trees and old trees to ensure we never end up with barren streets burning in the heat of summer. Furthermore, it requires us to choose trees that will survive the hotter and drier future that awaits us.

But most of all, it is but another reason why we need to realise that we never are, and never will be, distinct and separate from nature. The distinction, if it was ever there at all, is porous and malleable. Nature's heart beats to the same ceaseless rhythm in the misty wilderness reserves as it does in the sprawling metropolis. It's just up to us to listen to it.