KEY ISSUES: SUSTAINABILITY AND ENVIRONMENT
Biodiversity
Plantation forestry — involving both non-native and native tree species — is increasing, although it still only occupies a small percentage of suitable agricultural land. For the most part in Australia, plantations are established on land already cleared and are managed much like agriculture. They need to be seen as such. It is unrealistic, therefore, given the cost and price pressures of the market, to expect plantations to be able to achieve the biodiversity of native forests, but much can be done to ensure they make a contribution to conserving and enhancing Australia’s biodiversity.
According to the most recent comprehensive publication on this topic in Australia 'Trees and Biodiversity' by Salt and Lindemayer, “There are no precise formulas or prescriptions (yet).” However there is much that can be learnt from efforts to date and much research is currently being undertaken to improve understanding of how to improve the biodiversity conservation of plantations. Salt and Lindenmayers’ book is the first to provide a comprehensive basic framework for improving the biodiversity value of various forms of farm forestry.
In 2003 CSIRO overviewed the scientific research that reported little positive to say about biodiversity and plantations. New reports show that, even though the CSIRO report is only a few years old, considerable research into biodiversity in plantations has been done since it was compiled. The new studies have shown that plantations, if well designed, can contribute much more than previously thought to biodiversity conservation.
The Tumut Fragmentation Experiment has identified some of the ways for such biodiversity improvement. The experiment is focused on the Buccleuch State Forest 100km west of Canberra in southern New South Wales, a 50,000 ha plantation of radiata pine (Pinus radiata), an exotic softwood species established on areas that formerly supported native eucalypt forest.
The study found that larger patches of remnant vegetation support more native animals than smaller patches, which is logical, but an interesting finding was that patches as small as half a hectare support much higher number of vertebrates than previously realised. Remnant patches close to (<500m) large continuous areas of native vegetation are more likely to be occupied by some vertebrate taxa (e.g. small mammals and arboreal marsupials) than more isolated ones. However, even isolated patches can have significant conservation value for many species (e.g. birds).
Remnant protection is often given as a priority to riparian areas (along waterways). The Tumut research confirmed that riparian areas are indeed a priority area in the landscape for the movement, dispersal and habitat of fauna. Streamlines and gullies should be targeted for retention during plantation development, preferably linking existing patches of bush. Therefore large plantations, even of exotic vegetation like radiata pine, can retain significant biodiversity value if they contain a mosaic of remnant patches of native vegetation, especially if these are linked by riparian native vegetation.
Many investigations are now being initiated, similar to the Tumut experiment, and it is expected that the understanding of how to improve the biodiversity value of plantations will increase considerably in the coming years. CSIRO Sustainable Ecosystems Division is developing a rating system for biodiversity and plantation forests using Salt and Lindenmayers’ work. Initial discussions have suggested that it may also be possible to adapt this work to develop a scoring system, incorporating issues such as vegetation retention and fragmentation to assess the consideration of biodiversity at a company and industry level.
Supporting strategies
A3P's Sustainability Action Plan commits members to:
- Assist the development of structures that enhance biodiversity benefits from plantations including
biodiversity credits. - Undertake monitoring and protection of biodiversity.
- Integrate the identification, evaluation and management of biodiversity into planning, decision
making and reporting. - Siting and design of plantations to complement remnant native vegetation.
- Protect riparian zones.
Timber Information
Free technical information on the source, selection, properties and other atributes of plantation timber based products available for use in building and construction applications.