You are viewing an archived copy of this website captured Fri Sep 23 12:38:13 AEST 2011

A new silviculture for Tasmania’s public forests

The former Prime Minister, the Hon. John Howard, and the former Premier of Tasmania, the Hon. Paul Lennon, jointly announced the Tasmanian Community Forest Agreement (TCFA) on 13 May 2005.

The TCFA is a joint commitment of the Australian and Tasmanian Governments to enhance conservation of Tasmania’s oldgrowth forests and development of the Tasmanian forest industry.

One component of the TCFA is to facilitate research into alternatives to the use of clearfelling in oldgrowth forests. This commits the Australian and Tasmanian Governments to cooperate in a program to facilitate reduction in the use of clearfell harvesting in oldgrowth forests to less than 20 per cent of the annual harvest of such coupes by 2010.

The Australian Government’s contribution of $2 million for this research program supplements the $11.1 million being invested by Tasmania in further research and implementation, including training and support for harvesting contractors. The joint investment facilitated acceleration of the research associated with the Silvicultural Systems Trial at the Warra LTER site in southern Tasmania, and enabled its expansion into other forests in other parts of the State.

As a result, variable retention silviculture is being implemented as the main alternative to clearfelling, and in 2009 the program was fully summarised and reviewed in a major document ‘A New Silviculture for Tasmania’s Public Forests’.

The review was informed by a Science Panel of internationally recognised experts in forest and conservation science, and by the major themes of the Old Forests, New Management conference held in Hobart in February 2008. This report confirms that it is possible to achieve by 2010 the non-clearfelling target of less than 20 per cent of the annual harvest of coupes containing oldgrowth forest. By doing this, the report’s findings provide the pathway to achieving the next step forward for environmental forestry. Variable retention is now the global standard for best practice when harvesting oldgrowth forests. Forestry Tasmania has articulated the option of extending the use of variable retention into regrowth forests where oldgrowth elements
are sparse, to improve biodiversity outcomes and provide continuing habitat for a range of species.

Scientific thinking is thus moving away from a narrow focus on protection of oldgrowth forest, towards a greater focus on maintaining mature forest elements across the whole forest. The extent of variable retention will be limited by the increased costs involved, operational difficulties and continuing the Forestry Tasmania obligation to make available 300 000 m3 of sawlogs and veneer logs annually.

Currently it is possible to harvest 1 000 hectares of forest by variable retention each year, although that area could be increased if on-coupe burning risks change following establishment of a biomass plant. Variable retention costs $5.20 a tonne more than clearfelling, which equates to more than $1 million in extra costs over the 1 000 hectares.

The successful development of variable retention builds on a succession of measures to improve environmental management of Tasmanian State forests since the Forest and Forest Industry Strategy in 1990. These include the protection of one million hectares of oldgrowth forest, cessation of use of 1080 poison and atrazine, and the end to conversion of native forest to plantation. The Sustainability Charter released in 2008 affirms Forestry Tasmania’s commitment to reserve at least 250 000 hectares of oldgrowth forest on State forest, a quarter of all oldgrowth forest protected in Tasmania.