Status of Australia’s Forest Genetic Resources 2021

Australia has approximately 2,500 native tree species, the main genera being wattles (the genus Acacia, with almost 1,000 species) and eucalypts (the genera Eucalyptus, Corymbia and Angophora, with approximately 800 species). A total of 129 forest tree species and hybrids are listed by the FAO as forest genetic resources for Australia, including 115 native species and hybrids. These include species used for wood products, as well as species used for food, oil and fodder; this list includes some iconic and some threatened Australian forest species.

Australia’s commercial plantation forests consists of exotic (non-native) softwood species such as Pinus radiata, P. caribaea and hybrids, and native hardwood species such as Eucalyptus globulus, E. nitens and E. grandis, as well as the native softwood species Araucaria cunninghamii. Australia’s commercial softwood plantations are mostly managed on long rotations for sawn timber, while the commercial hardwood plantations are mostly managed on short rotations for pulpwood.

Australia relies on in situ conservation as the main mechanism for conservation of forest genetic resources, but also has ex situ programs for a range of forest tree and other plant species.

All the 115 native species and hybrids on the FAO list of forest genetic resources for Australia have populations conserved in situ in formal and informal reserves and protected areas; some of these species are also formally protected under legislation. Australia’s national, state and territory governments have regulations to limit and control the removal of plant and animal products from public and private forests. Management of production forests is regulated under state and territory legislation, with ecologically sustainable forest management an explicit goal, including the conservation and use of forest genetic resources.

Australia’s programs for ex situ conservation of forest species include seed banks, living collections, conservation stands, and seed orchards. Seed banks hold seed for 127 of the 129 species and hybrids listed by FAO as forest genetic resources for Australia. The Australian Tree Seed Centre is a major seed bank based at CSIRO, and a key supplier of seed for forestry species. Seed is also supplied from commercial seed orchards and some conservation plantings that have been converted to seed stands. A range of other seedbanks, including through the Australian Seed Bank Partnership, provide seed for conservation, research and revegetation projects.

Most Australian genetic diversity work has been done on forestry species or threatened species. Currently, knowledge from non-molecular characterisation of within-species diversity (including from provenance and other trials) is not formally inventoried at a national or sub-national level. However, molecular and genomic data are now being captured by various national projects and databases.

The genetic resources of Australia's forests play a critical role in maintaining and developing plantation productivity. Attributes used for selection in tree breeding programs include faster growth, improved wood quality, pest resistance, and adaptability to different environments. Ongoing access to forest genetic resources will allow selection and development of tree crops more suited to the warmer and drier conditions predicted for southern and eastern Australia under climate change, or to the warmer and wetter conditions predicted for northern Australia.

Molecular technologies, and marker-assisted selection, are increasingly used in Australia and overseas to characterise species and assist breeding programs. Genomic sequencing of flooded gum (Eucalyptus grandis), a key plantation eucalypt species, will accelerate eucalypt selection and breeding for productivity and wood quality. More than 200 Australian forest species have been examined for population genetic variation using molecular techniques, including 76 of the species listed by FAO as forest genetic resources for Australia.

There are at least 16,836 native vascular flora species (plants) in Australia’s forests. Of these, 1,074 were listed as threatened species under the Commonwealth Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act) as at 2016. Seventeen of the species on the FAO list of forest genetic resources for Australia are listed as threatened under the EPBC Act. Australia’s main plantation species, and the majority of other tree species of economic and social importance, are not listed as threatened species. State and territory legislation also protects threatened species within jurisdictions.

Habitat fragmentation, reduction in population sizes, and spatial isolation of populations are threats that can reduce genetic variation within populations, and increase genetic divergence between populations, due to effects on gene flow and breeding. Changes in genetic diversity and breeding systems associated with these factors have been shown for several forest species. Depending on the species, Australia’s management responses vary from storage (banking) of genetic material as seed, restoring connectivity between populations, and assisted translocation. Revegetation using seed sources that match the projected future climate may confer greater climate resilience on forests.

Australia is a party to international agreements, treaties and conventions that are directly or indirectly relevant to the conservation, sustainable use and development of forest genetic resources. These include the Convention on Biological Diversity, the International Tropical Timber Agreement, and the World Trade Organisation Agreement on the Application of Sanitary and Phytosanitary Measures.