Clearfelling

Otway Ranges

In simple terms, clearfelling is the removal or burning of nearly all the living matter in a given area of forest known as a coupe. Most coupes in Victoria are around 40 hectares in size.

The Department of Natural Resources and Environment (DNRE) forestry experts adopted this method of logging because it is cost effective i.e. the most amount of timber for the least amount of effort. Despite constant criticism and evidence to the contrary from public and scientists alike they still claim that this clearing and burning "mimics" natural processes! It's hard to imagine a natural process that leaves results like those of a logtruck, bulldozer or similar twenty tonne piece of logging machinery that either compacts or grinds through the soil sometimes bringing acid sulphate subsoils to the surface. This results in complex chemical reactions which in turn cause problems for soil micro flora and fauna etc.

Another problem arises when deep ruts and channels from machine tracks fill up and fester with toxic, stagnant and pathogen filled water that runs into waterways following rain. Sediment run-off also suffocates and fills rivers and estuaries.

Central Highlands

Other negative impacts from clearfelling include

N.E. Victoria

Clearfelling:

·  disturbs natural ecotones within forest. Ecotonal, or transitional forest has more diversity.

·  destroys the undergrowth which can be older than the trees in the forest.

·  disturbs soil structure resulting in changes to soil flora and fauna.

·  releases toxic compounds and elements from the soil into the environment.

·  produces sediments that choke and poison waterways.

·  poses risks to human health from pathogens like giardia that breed in depressions left by logging machinery.

· exposes rainforest to drying effects.

·  requires bait laying to deter natural predation e.g. 1080 baits to kill wallabies.

 

Dense regrowth forests from clearfelling:

·  pose increased fire risk to sensitive vegetation communities like rainforest gullies.

       ·   suppress competing species thereby altering forest composition (logging in short rotations prevents forest from developing mature structural charcteristics e.g. diverse understorey)

       ·  are not suitable habitat for many species as they are in a perpetual state of arrested development. (see point above)

From The AGE

Clear-felling: a big, burning issue

By Claire Miller

May 13 2002

If a picture speaks a thousand words, then the image of a freshly clear-felled coupe, blackened and smoking, tells a confusing story. For conservationists, it is an image of wanton destruction to feed a voracious export woodchip market. But for the state's forest managers and the timber industry, clear-felling is about renewal. Sure, it is not pretty to start with, but within a few short years, a better forest is growing back. In principle, the practice is ''natural" because it mimics the effects of wildfires. Certainly the aftermath of clear-felling and wildfires look pretty much the same at first glance, except that a fire generally leaves far more trees standing and alive.

Clearfell logging in Melbournes water catchment.

But such subtle differences tell another story - that clear-felling may be changing native forests in ways anything but natural. Peer-reviewed scientific research here and overseas suggests clear-felling has serious, long-term and negative ecological effects. Such concerns have led to clear-felling being reviewed, modified, and in some cases, abandoned in developed countries such as the United States and Canada. In view of such concerns, Environment and Conservation Minister Sherryl Garbutt has commissioned a review by Melbourne University's Forest Science Centre. Centre director Mark Adams says the review of the scientific literature would highlight how different forest types respond to logging and other disturbances, natural and man-made.

A spokesman for Garbutt says logging practices generate much community debate and the government has a responsibility to obtain the best and most accurate information. "We would be negligent if we didn't do it." He says the findings of the review would be "an important tool in developing future forestry policies". About 30 per cent of Victoria's forests with commercial potential are open to logging after taking out reserves, stream buffer zones, and other constraints, according to Forestry Victoria general manager Peter Rutherford. About half the 12,000 hectares logged each year is clear-felled. Forestry Victoria operations manager Peter Ford says clear-felling is the way to get a healthy, growing forest. Often in the past the best trees and species were selectively removed so that forests were no longer representative of their natural state. Starting over meant the original mix could be regenerated. "We try to mimic nature and get the product out at the same time," he says. But Simon Birrell of the Otway Range Environment Network says clear-felling changes biodiverse forests into an artificial environment. "It is no longer natural, it is something of human creation," he says. Humans have already transformed so much of the landscape through agriculture and plantations that what little natural land is left should be protected.

"The "mosaic" of forests of different ages"...?

Clear-felling has strong industry and union support. Victorian Association of Forest Industries public affairs director Pat Wilson says clear-felling is not appropriate in every case, but it is safer for workers and seems to promote better regeneration. He says the industry would need to be convinced alternatives were safer and promoted better-quality trees. Clear-felling is also more economic than selective logging. Trees destined for woodchipping are removed at the same time as logs for value-adding in sawmills, adding to contractors' incomes. In the Otways, for example, cutting and transporting woodchip logs accounts for 60 per cent of the loggers' income, according to Freedom of Information documents. However, forest ecology experts say the suitability of clear-felling depends on whether the forest is managed primarily for timber production or not. They say clear-felling, particularly on the short 60-80 year rotations practised in Victoria, is reducing the overall diversity and abundance of wildlife and plant species, lowering water run-off, and, arguably, making forests more vulnerable to fire.

In 1998, the Cooperative Research Centre for Catchment Hydrology reported that run-off from a clear-felled coupe in a mountain ash forest halves over the first 40 years and does not recover until the regrowth is more than 150 years old. This means an extra 17,000 megalitres of water a year would flow into Melbourne's Thomson Dam if the forest was left to grow old, according to a government-appointed committee discussion paper on meeting future water needs. The $147 million value of the extra water compares with the $1.43 million a year the government earns from the logging.

Similarly, according to a 2001 Sinclair Knight Mertz report for the government, run-off would rise 10 per cent and 26 per cent by 2080 for Geelong and Warrnambool respectively if clear-felling stopped in their Otways catchments. The report also says there is a rapid drop in water yield in the event of a severe wildfire. But Adelaide University paleo-ecologist Peter Gell says there is a critical difference. Charcoal records suggest that, in prehistoric times, severe wildfires comparable in effects to clear-felling swept through Victoria's tall, wet forests perhaps only once every 300 years. This compares with clear-felling every few decades. But Gell says the frequency and intensity of fires has increased dramatically since white settlement and has changed the character of the forests. Clear-felling has continued that pattern of human-induced change.

The CSIRO's Malcolm Gill, an expert in fire ecology, says if forest managers are interested only in timber values, then clear-felling could be similar to wildfire in terms of boosting the regeneration of certain trees, like the commercially valuable mountain ash. But he says clear-felling and wildfires have different impacts if other concerns are taken into account. For example, trees take at least 150 years to form hollows, upon which a third of native fauna species rely for breeding, shelter and prey. ''If you are cutting the trees at 60 years and it takes hollows 150 years to form, then anything dependent on the hollows is doomed," Gill says.

Australian National University biologist David Lindenmayer has spent almost 20 years studying the ecology of Victoria's mountain ash forests. He says wildfires leave a centuries-old biological and structural legacy. Clear-felling, on the other hand, removes almost all vegetation, so that a quite different, botanically simplified and even-aged forest grows back. Lindenmayer says clear-felling leaves too few trees to sustain species relying on hollows. Victoria's endangered faunal emblem, the Leadbeaters possum, for example, suffers because it needs multiaged forests where short-lived, fire-loving forage trees stand under a canopy of old, hollow-bearing giants that have survived a series of mild and moderate blazes over the centuries. He says logging should be varied according to natural landscape variations. He says other countries such as Sweden are adjusting methods to resemble local patterns of natural disturbance. This means, for example, that a patch with little natural fire history would never be logged. ''We are behind the world in best practice and we have some work to do to catch up now," he says.

Consultant ecologist and former head of the Natural Resources and Environment Department's forest flora unit, Steve Mueck, says clear-felling is a long-term fire hazard because the forest that grows back contains a mix of species typical of drier forest types. It is therefore at risk of burning more frequently with greater intensity and speed. Mueck says clear-felling dramatically reduces the abundance of long-lived plants like tree ferns that otherwise recover quickly from wildfires and help suppress blazes by keeping the forest floor damp. Dense regrowth of saplings also creates an oil-rich canopy closer to the ground, making it easier for flames to jump into the tree-tops and race away. "In a situation where wetter (plant) components have been eliminated, the forest is drier and structurally there is a great opportunity for fires to start, so we are building a potential firebomb. "This is not to say it wasn't flammable to start with, but we are making the situation worse from a fire perspective." Principal fellow at Melbourne University's School of Botany, Peter Attiwell, says while there is evidence that species typical of drier forests do invade after clear-felling, no studies have been done to establish if there is a missing link leading to more flammable forests.

Forests are complex. It is difficult to generalise across different types, topography and climatic conditions. It is possible to find botanically diverse regrowth forests, and old growth forests as botanically diverse as clear-felled areas. Since any forest would burn under the right sorts of conditions, he says it is a matter of degree whether, overall, they burn more or less in the decades after clear-felling. Attiwell says it would be difficult to show conclusively that clear-felling really tipped the balance towards a more flammable kind of forest.

Head of geospatial science at RMIT University in Melbourne, Tony Norton, says it is not true that clear-felling mimics the ecological effects of wildfires. "There are plenty of scientific journal articles written in the last 15 years indicating how the impacts of clear-felling actually do not mimic natural disturbances in these forests - but we haven't moved too far to reflect that in our forest management."