1. Develop an agreed list of significant characteristics of eucalypts and eucalypt-dominated vegetation that contribute to the outstanding universal value of the sub-theme of “eucalypt-dominated vegetation”.
2. Revise the draft technical report on the sub-theme of eucalypt-dominated vegetation so that it provides an appropriate summary of the significant characteristics of eucalypts and eucalypt-dominated vegetation that contribute to their outstanding universal value.
3. Provide advice where appropriate on likely data requirements for future assessment of areas identified by the World Heritage Expert Panel as having potential World Heritage significance in representing the eucalypt sub-theme.
4. Provide comments on drafts and assist where necessary with the development of the final report of the workshop.
Within this regional context, eight broad eucalypt-dominated vegetation types were recognised by Beadle (1981). He noted that eucalypt species dominate most of the regions with higher rainfall. The species generally differ from region to region, except for a few which occur in two contiguous regions. A brief summary, derived from Beadle (1981), of each of the major eucalypt-dominated vegetation types classified at the continental scale follows.
1. Eucalypt Communities of the Tropics
The northern tropical regions are characterised by summer rainfall and winter drought. Much of the area supports eucalypt forests and woodlands, broadly divided into two regional components by the Gulf of Carpentaria and its associated grassland areas. All subgenera are represented in these tropical regions. A high proportion of eucalypt taxa are from three subgenera Blakella, Corymbia and Eudesmia, and many of these are community dominants.
2. Tall Eucalypt Forests of the Eastern Coastal Lowlands on soils of higher fertility
The tall eucalypt forests on fertile soils occur mainly in the temperate areas of northern New South Wales extending into southern and central Queensland. Relict stands also occur north of the Tropic. These tall forests typically occur at warmer coastal lowlands sites, but also extend up onto the cooler tablelands of the Divide. They often share a common boundary with rainforest vegetation and rainforest species are common in the understorey. Eucalyptus robusta forests with a predominantly grassy or halophytic understorey located adjacent to the littoral zone are included amongst these forests.
3. Eucalypt Forests and Woodlands of the Eastern Coastal Lowlands on soils of lower fertility
The forest and woodland communities on less fertile soils extend down the east coast, from near the Tropic into Victoria. They give way to heath vegetation on the poorest soils or where drainage is poor, and also intergrade with the tall forests on more fertile soils. The understorey vegetation includes a major scleromorphic component, which generally increases in species diversity from north to south, and reaches its maximum expression on the sandstones of the Sydney region. Some of the eucalypt dominants have a broad latitudinal range, whereas others are restricted in their distribution, generally either to the northern or southern part of the region.
4. Eucalypt Communities of the cooler climates of the Eastern Highlands, Lowland Victoria and Tasmania
Cold-adapted eucalypt forests and woodlands dominate the higher parts (above 1000 metres) of the Great Divide, extending to treeline. The higher parts of the Divide broadly include the Northern, Central and Southern Tablelands regions of New South Wales, and the Southern Alps region in the south-east of the continent, which extends from the Koscuiszko plateau into Victoria. High altitude areas also occur in parts of Tasmania. In these regions, the higher parts of the Divide separate the wetter, eastern flora from the drier, western flora. In general, the species assemblage of the northern parts of the Divide differs from that of the southern parts. Species with a wide latitudinal range also occur, extending to progressively lower altitudes from north to south. Some species have wide altitudinal ranges and several display pronounced ecotypic variation with altitude.
5. The Ironbark Forests and Woodlands
Ironbark forests and woodlands typically occur on lower fertility soils, extending from Cape York Peninsula to Victoria. In the north, they occur from the coast across the Great Divide to semi-arid, inland areas. In the south, they are confined to drier areas adjacent to and west of the Divide, although some taxa also occur in rainshadow areas in the lowlands to the east of the Divide. Two broad species groups can be distinguished. One, which mostly includes taxa in Series Pruinosae, occurs mainly in northern regions with summer rainfall. The other, which comprises Eucalyptus sideroxylon, Series Melliodorae, and taxa in Series Paniculatae, occurs predominantly in southern areas with winter rainfall. Ironbark forests and woodlands adjoin all of the other eastern eucalypt communities, except for the higher altitude communities. They also co-occur with other species of Eucalyptus and Angophora, and include a large number of ecotonal associations.
6. The Box Woodlands of the East and South-east
The box woodlands occur in drier areas in the eastern and southern parts of the continent, extending from Cape York Peninsula to South Australia. They effectively separate the forests of wetter coastal and montane areas from the arid interior of the continent, although they also extend into coastal regions associated with areas of rainshadow. The box woodlands are dominated by species in the subgenus Symphyomyrtus. The species tend to be stratified latitudinally, but also display areas of overlapping distribution and ecotonal interaction.
Mallee communities are dominated by multi-stemmed, shrub forms of Eucalyptus. They typically extend across the southern half of the continent in areas of between 220 and 375 mm mean annual rainfall. The southern area of mallee fringes the arid zone, and is broadly divided into eastern and western components by the Nullarbor Plain and Great Australian Bight. Some mallee species are widely distributed, but many are restricted in their distribution to the east or the west. Mallee communities occur as isolated patches scattered throughout the arid interior of the continent, and extend as far north as the Tropic. Some mallee outliers also occur in wetter areas; these are apparently relictual and may reflect a former, wider distribution of this vegetation type. Marlock communities are structurally similar to mallee, but are dominated by single-stemmed, shrub forms of Eucalyptus. They are found in drier parts of the south-west of the continent. The composition of the understorey of mallee vegetation varies widely, depending on soil factors.
8. Eucalypt Forests and Woodlands in the South-West
Eucalypt forests and woodlands dominate higher rainfall areas in the south-west of the continent. The forest communities are restricted to the wetter areas in the far south-west, whereas woodland vegetation extends into the drier regions to the east. Rainfall and soil type are major determinants of eucalypt species distribution. The tallest forests of karri (Eucalyptus diversicolor) and red tingle (Eucalyptus jacksonii) occur in the few wetter areas with fertile soils. Extensive lateritic soils support forests of jarrah (Eucalyptus marginata) and marri (Eucalyptus calophylla), and the tuart forests (Eucalyptus gomphocephala) are associated with coastal limestones. In response to decreasing rainfall, some of these forest dominants may exhibit decreasing stature, but all are eventually replaced by other eucalypt species. Areas of forest and woodland are frequently interspersed with extensive areas of mallee and marlock, or with non-eucalypt heath communities, in response to low nutrient soils or impeded drainage.